CN104756238A

CN104756238A - A method of controlling the switched mode ion energy distribution system

Info

Publication number: CN104756238A
Application number: CN201380056068.5A
Authority: CN
Inventors: V·布劳克; D·J·霍夫曼; D·卡特
Original assignee: Advanced Energy Industries Inc
Current assignee: Advanced Engineering Solutions Global Holdings Private Limited
Priority date: 2012-08-28
Filing date: 2013-08-26
Publication date: 2015-07-01
Anticipated expiration: 2033-08-26
Also published as: CN107978506B; WO2014035897A1; JP2015534212A; CN104756238B; KR101860182B1; JP6986113B2; JP2018152349A; CN107978506A; JP6329542B2; KR20150046251A; JP2020155408A

Abstract

Systems, methods and apparatus for regulating ion energies in a plasma chamber and chucking a substrate to a substrate support are disclosed. An exemplary method includes placing a substrate in a plasma chamber, forming a plasma in the plasma chamber, controllably switching power to the substrate so as to apply a periodic voltage function (or a modified periodic voltage function) to the substrate, and modulating, over multiple cycles of the periodic voltage function, the periodic voltage function responsive to a defined distribution of energies of ions at the surface of the substrate so as to effectuate the defined distribution of ion energies on a time-averaged basis.

Description

The method of control switch pattern ion energy distribution system

Related Cases and priority

This application is the U.S. Patent Application No. No.13/193 submitted on July 28th, 2011, the non-provisional U.S. Patent Application No. No.12/870 that the part continuation application of 299 and on August 29th, 2010 submit to, the part continuation application of 837.Application number No.13/193,299 and No.12/870, the details of 837 quotes in full mode with it and is incorporated in the application for all applicable objects.

Technical field

Present disclosure relates generally to plasma treatment.Specifically, the present invention relates to plasmaassisted etching, deposition and/or the method and apparatus of other plasma assisted process, but be not limited thereto.

Background technology

Very eurypalynous semiconductor device utilizes the etching technique based on plasma to manufacture.If conductor is etched, then the negative voltage relative to ground can be applied to conductive substrates, to create substantially consistent negative voltage at the surperficial two ends of liner conductor, the ion of positively charged attracts to conductor by it, and result, the cation of collision conductor has identical energy substantially.

But if substrate is dielectric, then the voltage of indeclinable voltage to the surperficial two ends at substrate is inoperative.But AC voltage (such as, high frequency) can be applied to conductive plate (chuck), goes out voltage to make AC region at the surface induction of substrate.During the positive half period in AC cycle, substrate suction phase is light electronics for the quality of cation; Thus a lot of electrons attracted to the surface of substrate in positive half period.As a result, the surface of substrate will be electronegative, and this makes ion will be attracted to electronegative surface.And when ionic bombardment substrate surperficial, clash into and the surface of material from substrate is evicted from, complete etching.

In many cases, expect to have narrow ion energy distribution, but sine wave being applied to substrate can induce wide ion energy distribution, which has limited the ability of the etching outline of plasma treatment carry out desired.Known realize that narrow ion energy distribution technology is very expensive, efficiency is low, be difficult to control and adversely may affect plasma density.As a result, useless being commercially used of these known technology adopted.Correspondingly, a kind of system and method is needed to solve the deficiency of current technology and provide other novel and creationary feature.

Summary of the invention

Below summarise the one exemplary embodiment of the present disclosure shown in accompanying drawing.These and other embodiment will more fully be described in embodiment part.But, should be appreciated that the intention not existing and the present invention is limited to summary of the invention part or the form described in embodiment part.One skilled in the art will recognize that many meetings fall into the amendment in the spirit and scope of the present invention as expressed in claim, equivalent and alternative structure.

According to an embodiment, the present invention can be characterized by a kind of method for setting up one or more plasma sheath voltage.The substrate support that described method can comprise to plasma chamber provides modified periodic voltage function.Described substrate support can be coupled to the substrate being configured in and carrying out in plasma processing.Equally, described modified periodic voltage function can comprise the periodic voltage function being compensated Ic amendment by ionic current.Described modified periodic voltage function can comprise the part between pulse and described pulse.Equally, described pulse can be the function of described periodic voltage function, and the slope of part between described pulse can be the function that described ionic current compensates Ic.Described method can also comprise the effective capacitance value C that access at least represents the electric capacity of described substrate support ₁.Described method finally can identify that the described ionic current of the ion energy distribution function defined of the ion by producing the surface arriving described substrate compensates the value of Ic, and wherein, described identification is described effective capacitance C ₁and the slope dV of described part between described pulse ₀the function of/dt.

According to another embodiment, the present invention can be described as a kind ofly carrying out for plasma the method that the biased thus surface of substrate in plasma processing chamber realizes the ion energy of definition.Described method can comprise the modified periodic voltage function applying to comprise the periodic voltage function being compensated amendment by ionic current to substrate support.Described method also can comprise samples to produce voltage data point at least one circulation of described modified periodic voltage function.Described method also can comprise the numerical value estimating first ion energy at described substrate surface place according to described voltage data point.Equally, described method can comprise the described modified periodic voltage function of adjustment, until described first ion energy equals the ion energy of described definition.

According to another embodiment, the present invention can be characterized by a kind of method in order to realize ion energy distribution function width.The substrate support that described method can comprise to plasma processing chamber provides modified periodic voltage function.Described method also can be included in for the first moment and in the second moment from described nonsinusoidal waveform sampling at least two voltages.Described method can comprise in addition the slope of described at least two voltages is calculated as dV/dt.Equally, described method can comprise and compares, described slope and known reference slope so that corresponding with ion energy distribution function width.Finally, described method can comprise the described modified periodic voltage function of adjustment, to make described slope close to described with reference to slope.

The another aspect of present disclosure can be characterized by a kind of device, comprises power supply, ionic current compensating unit and controller.Described power supply can provide periodic voltage function, and described periodic voltage function has the part between pulse and described pulse.Described ionic current compensating unit can revise the slope of the described part between described pulse, to form modified periodic voltage function.Described modified periodic voltage function can be configured to, for being provided to substrate support, process in plasma processing chamber.Described controller can be coupled to described switched-mode power supply and described ionic current compensating unit.Described controller can also be configured to the numerical value identifying that described ionic current compensates, if provide described ionic current to compensate to described substrate support, will produce the ion energy distribution function of the definition of the ion on the surface arriving described substrate.

The another aspect of present disclosure can be characterized by a kind of tangible computer readable storage medium storing program for executing of non-transitory, and its coding has processor instructions, to perform the method for monitoring the ionic current being configured to the plasma processing substrate.Described method can comprise: under considering the ionic current compensation situation with the first numerical value, modified periodic voltage function is sampled, and under considering the described ionic current compensation situation with second value, described modified periodic voltage function is sampled.Described method also can comprise the slope determining the described modified periodic voltage function of the function as the time based on described first sampling and described second sampling.Described method also determines the slope of the described modified periodic voltage function of the function as the time based on described first sampling and described second sampling.Described method finally can comprise the third value calculating the compensation of described ionic current based on described slope, and at described third value place, at least one cycle memory at described modified periodic voltage function exists by the constant voltage on described substrate.

These embodiments and other embodiment are described in further detail herein.

Accompanying drawing explanation

By referring to following embodiment and appended claims by reference to the accompanying drawings simultaneously, each object of the present invention and advantage and more complete understanding can be apparent and be easier to understand, wherein, throughout several accompanying drawing, identical Reference numeral refers to same or similar element, and in the accompanying drawings:

Fig. 1 shows the block diagram of the plasma process system according to an embodiment of the invention;

Fig. 2 shows the block diagram of the one exemplary embodiment of the switched-mode power supply system shown in Fig. 1;

Fig. 3 is that the schematic diagram that can be used for the parts realizing the switching mode bias supply described with reference to figure 2 represents;

Fig. 4 shows the sequential chart of two drive signal waveform;

Fig. 5 is the diagrammatic representation of the monotype of the console switch mode bias power supply realizing the ion energy distribution concentrated at specific ion energy place;

Fig. 6 shows the diagram of the bimodal pattern of the operation at the discrete peak of two of wherein generating in ion energy distribution;

Fig. 7 A and Fig. 7 B show carry out in plasma reality, direct ion energy measurement diagram;

Fig. 8 shows the block diagram of an alternative embodiment of the invention;

Fig. 9 A is the diagram that the exemplary periodic voltage function modulated by sinusoidal modulation function is shown;

Fig. 9 B is the exploded view of a part for the periodic voltage function shown in Fig. 9 A;

Fig. 9 C show obtained by the Sine Modulated of periodic voltage function, based on the time averaging ion energy distribution obtained;

Fig. 9 D shows in the plasma of the time averaging IEDF obtained when periodic voltage function is modulated by sinusoidal modulation function the actual direct ion energy measurement carried out;

Figure 10 A shows the periodic voltage function by saw tooth modulation FUNCTION MODULATION;

Figure 10 B is the exploded view of a part for the periodic voltage function shown in Figure 10 A;

Figure 10 C show obtained by the Sine Modulated of the periodic voltage function in Figure 10 A and 10B, based on the diagram of the distribution of time averaging obtained ion energy;

Figure 11 is the diagram of modulating function IEDF function being shown in the right column and being associated shown in left column;

Figure 12 shows the block diagram of the embodiment of the ionic current of its ion current compensating unit compensation plasma body indoor;

Figure 13 shows the diagram of exemplary ion current compensation parts;

Figure 14 shows the diagram of the exemplary voltage at node Vo place shown in fig. 13;

Figure 15 A-15C is in response to the voltage waveform that offset current occurs in the surface of substrate or wafer;

Figure 16 is the one exemplary embodiment that may be embodied as the current source realized with reference to the current source described by Figure 13;

Figure 17 A and 17B shows the block diagram of other embodiments of the invention;

Figure 18 shows the block diagram of an alternative embodiment of the invention;

Figure 19 shows the block diagram of another embodiment of the present invention;

Figure 20 is can in conjunction with the input parameter used with reference to the embodiment described by figure 1-19 and the block diagram controlling output;

Figure 21 shows the block diagram of another embodiment of the present invention;

Figure 22 shows the block diagram of another embodiment of the present invention;

Figure 23 shows the block diagram of another embodiment of the present invention;

Figure 24 shows the block diagram of another embodiment of the present invention;

Figure 25 shows the block diagram of another embodiment of the present invention;

Figure 26 shows the block diagram of another embodiment of the present invention;

Figure 27 shows the block diagram of another embodiment of the present invention;

Figure 28 shows the method for the embodiment according to present disclosure;

Figure 29 shows the another kind of method of the embodiment according to present disclosure;

Figure 30 shows an embodiment of the method for the ion energy distribution of the ion on the surface controlling collision substrate;

Figure 31 shows the method for arranging IEDF and ion energy;

Figure 32 shows two the modified periodic voltage function waveforms transmitted to substrate support of an embodiment according to present disclosure;

Figure 33 shows the ionic current waveform that can indicate plasma source unsteadiness in plasma density or change;

Figure 34 shows the ionic current I of the modified periodic voltage function waveform with shape aperiodic _i;

Figure 35 shows the modified periodic voltage function waveform of the fault that can indicate in bias supply;

Figure 36 shows can the modified periodic voltage function waveform of dynamic change of indication mechanism electric capacity;

Figure 37 shows the modified periodic voltage function waveform that can indicate the change of plasma density;

Figure 38 shows the sampling of the ionic current run for different process, and wherein, the drift in ionic current can indication mechanism be drifted about;

Figure 39 shows the sampling of the ionic current for different technical parameters.

Figure 40 shows in room without two offset waveform monitored when plasma;

Figure 41 shows two offset waveform that may be used for verifying plasma process;

Figure 42 shows some supply voltages and the ion energy figure of the relation between display power supply voltage and ion energy;

Figure 43 shows an embodiment of the method for the ion energy distribution of the ion on the surface controlling collision substrate;

Figure 44 shows each waveform at the difference place in system disclosed in this article;

Figure 45 shows and carry out final increase change to make it mate ionic current I in ionic current compensation Ic _ieffect;

Figure 46 shows the selection of ion energy;

Figure 47 shows selection and the expansion of ion energy distribution function width;

Figure 48 shows the supply voltage V that may be used for realizing more than one ion energy level _pSa pattern, wherein, each ion energy level has narrow IEDF width;

Figure 49 shows the supply voltage V that may be used for realizing more than one ion energy level _pSanother pattern, wherein, each ion energy level has narrow IEDF width; And

Figure 50 shows the supply voltage V that may be used for creating the IEDF defined _pSi is compensated with ionic current _ca combination.

Embodiment

The one exemplary embodiment of plasma process system is generally shows in Fig. 1.As shown, plasma electrical source 102 is coupled to plasma processing chamber 104, and switched-mode power supply 106 is coupled to support 108, and in room 104, substrate 110 is placed on support 108.Also show the controller 112 being coupled to switched-mode power supply 106.

In this exemplary embodiment, plasma processing chamber 104 can realize (such as, comprising by the emptying vacuum casting of one or more pump (not shown)) with the room of conventional structure substantially.In addition, it will be understood to those of skill in the art that, plasma in room 104 can by any one source forcing, such as comprise spiral plasma source, it comprises in order to excitation and the magnetic coil and the antenna that maintain the plasma 114 in reactor, and gas access can be provided to be introduced in room 104 by gas.

As shown, Exemplary plasma room 104 is set up and is configured to plasmaassisted is carried out in utilization material etches to the high-energy ion bombardment of substrate 110 and other plasma treatment (such as, plasma-deposited and plasmaassisted implanted ions).Plasma electrical source 102 in this embodiment to be configured under one or more frequency (such as, 13.56MHz) via matching network (not shown) by energy (such as, RF energy) be applied to room 104, so that excitation and maintain plasma 114.Should be appreciated that the invention is not restricted to arbitrary particular type in order to by Energy Coupling to the plasma electrical source 102 of room 104 or source, and by various frequency and energy level electric capacity or plasma 114 can be coupled to inductively.

As shown, dielectric substrate 110 (such as, semiconductor crystal wafer) to be processed supported by support 108 at least partly, support 108 can comprise a part (such as, for semiconductor crystal wafer process) for conventional wafer chuck.Support 108 can be formed as having insulating barrier between support 108 and substrate 110, and wherein substrate 110 is capacitively coupled to platform, but support 108 also can be floating with the voltage being different from support 108.

As mentioned above, if substrate 110 and support 108 are conductor, then fixed voltage can be applied to support 108, and due to the conductivity by substrate 110, the voltage being applied to support 108 is also applied to the surface of substrate 110.

But, under substrate 110 is dielectric situation, apply the treatment surface two ends generation voltage of fixed voltage to substrate 110 to support 108 inoperative.Therefore, exemplary switch mode power 106 is configured to controlled to realize attracting the ion in plasma 114 to carry out voltage collide with substrate 110 on the surface of substrate 110, thus the controlled etch of execution substrate 110 and/or deposition and/or other plasma assisted process.

In addition, as discussed herein further, the switched-mode power supply 106 of embodiment is configured to work to make substantially there is not interaction between the energy that applied by plasma electrical source 102 (to plasma 114) and the energy being applied to substrate 110 by switched-mode power supply 106.Such as, the energy applied by control switch mode power 106 is controlled, can control ion energy and substantially not affect plasma 114 density.

In addition, the embodiment of many exemplary switch mode powers 106 illustrated in fig. 1 is realized by the relatively inexpensive parts that can be controlled by relatively simple control algolithm.And compared with prior art, the embodiment of many switched-mode power supplies 106 is much effective; Thus reduce the cost of energy relevant with removing excessive heat energy and expensive material.

One known, and to execute alive technology to dielectric substrate be utilize high-power linear amplifier to combine with complicated control program, to apply energy to the substrate support portion inducing voltage at substrate surface.But, this technology also not adopt by commercial entity, reason does not also prove that this technology cost performance is high and is easy to management.Specifically, the linear amplifier used usually more greatly, very expensive, poor efficiency and be difficult to control.In addition, linear amplifier needs AC to be coupled (such as, blocking capacitor) inherently, and the miscellaneous function of similar chuck is by fed in parallel circuit realiration, and it can damage the AC frequency spectrum degree of purity of the system in the source with chuck.

The another kind of technology considered adds high frequency power (such as, utilizing one or more linear amplifier) to undercoat.But, because the high frequency power article on plasma volume density applied substrate has impact, therefore have been found that this technology article on plasma volume density has adverse influence.

In certain embodiments, the switched-mode power supply 106 shown in Fig. 1 can be realized by step-down, boosting or buck-boost type energy technologies.In these embodiments, the level of pulse power that changes can be applied, to induce electromotive force on the surface at substrate 110 by control switch mode power 106.

In other embodiments, switched-mode power supply 106 can be realized by other more complicated switched-mode power supply and control technology.Following reference diagram 2, such as, the switched-mode power supply described with reference to figure 1 is realized by switching mode bias supply 206, switching mode bias supply 206 for energy is applied to substrate 110, to realize the energetic ion of bombardment substrate 110 that one or more is expected.Also show ion energy control assembly 220, arc-detection parts 222 and be coupled to switching mode bias supply 206 and the controller both wave memorizer 224 212.

The setting of these shown parts is rational; Thus can combine in actual execution mode or be separated these parts further, and these parts can be connected in every way, and do not change the groundwork of system.Such as, in certain embodiments, the controller 212 that can be realized by hardware, software, firmware or its combination can be utilized to control both power supply 202 and switching mode bias supply 206.But in alternative embodiments, power supply 202 and switching mode bias supply 206 are realized by completely independently functional unit.Illustrate further, controller 212, wave memorizer 224, ion energy control part 220 and switching mode bias supply 206 can be integrated into single parts (such as, being arranged in common shell) or can be distributed in discrete parts.

Switching mode bias supply 206 in this embodiment is configured to apply voltage to support 208 in a controlled manner usually, to realize the Energy distribution of (definition) ion of the expectation of bombarding substrate surface.More specifically, switching mode bias supply 206 is configured to by the specific waveforms of one or more particular energy level being applied to substrate to realize (definition) ion energy distribution expected.And more specifically, in response to the input from ion energy control part 220, switching mode bias supply 206 applies particular energy level to realize specific ion energy, and utilizes the one or more voltage waveforms defined by the Wave data in wave memorizer 224 to apply specific energy level.Therefore, ionic control portion can be utilized to select one or more specific ion bombarding energy, to perform the controlled etching (or plasma treatment of other form) to substrate.

As shown, switched-mode power supply 206 comprises switch block 226 ', 226 " (such as; high-power field-effect transistor), it is in response to from corresponding driver part 228 ', 228 " drive singal energy is switched to the support 208 of substrate 210.And the timing defined based on the content of wave memorizer 224 and by controller 212 to by driver part 228 ', 228 " drive singal 230 ', 230 that produces " control.Such as, controller 212 in many embodiments be suitable for explain wave memorizer content and produce drive control signal 232 ', 232 ", drive control signal 232 ', 232 " by driver part 228 ', 228 " utilize control to switch block 226 ', 226 " drive singal 230 ', 230 ".Although show two switch blocks 226 ', 226 that can arrange with half-bridge configuration with exemplary object ", must expect realizing less or other switch block (such as, H bridge configuration) in various framework.

In various operational modes, drive control signal 232 ', 232 modulated by controller 212 (such as, utilizing Wave data) " timing so that substrate 210 support 208 realize expect waveform.In addition, switched-mode power supply 206 provides power supply based on ion energy control signal 234 pairs of substrates 210, control signal 234 can be DC signal or time become waveform.Therefore, the present embodiment can by the timing signal that controls to switch block and control by switch block 226 ', 226 " energy (being controlled by ion energy control assembly 220) that applies controls ion energy distribution.

In addition, the controller 212 in this embodiment is configured to: in response to the electric arc in the plasma chamber 204 detected by arc-detection parts 222 to perform arc-management function.In certain embodiments, when an arc is detected, controller 212 changes drive control signal 232 ', 232 ", to make the electric arc in the waveform extinguishing plasma 214 of the output 236 being applied to switched-mode power supply 206.In other embodiments, controller 212 is by simple drives interrupts control signal 232 ', 232 " applying carry out extinguish arcs, be interrupted with the applying of the energy making the output 236 of switching mode bias supply 206.

Following reference diagram 3, it is that the schematic diagram that may be used for the parts realizing the switching mode bias supply 206 described with reference to figure 2 represents.As shown, switch block T1 and T2 in this embodiment is arranged with half-bridge (being also referred to as totem) type topology.Jointly, R2, R3, C1 and C2 all represent plasma load, C10 is effective capacitance (being also referred to as series electrical perhaps chuck electric capacity herein), and C3 is selectable physical capacitor, to prevent from flowing through circuit from the voltage that substrate surface induces or from the DC electric current of the voltage of electrostatic chuck (not shown).C10 is called as effective capacitance, because it comprises series capacitance (or being also referred to as chuck electric capacity) of substrate support and electrostatic chuck (or e-chuck) and intrinsic other electric capacity of biased applying, and such as insulation and substrate.As shown, L1 is stray inductance (such as, to the inherent inductance of the conductor of load feeding electric energy).And in this embodiment, there are three inputs: Vbus, V2 and V4.

V2 and V4 represents that drive singal (such as, with reference to figure 2 describe by driver part 228 ', 228 " drive singal 230 ', 230 that exports "), and in this embodiment, can be V2 and V4 timing (pulse length and/or mutually delay), the closedown making it possible to modulate T1 and T2 exports the waveform of Vout with the voltage controlling to be applied to substrate support portion.In many embodiments, not perfect switch for realizing the transistor of switch block T1 and T2, therefore in order to reach the waveform of expectation, considering transistor special characteristic.Under many operator schemes, the timing changing V2 and V4 simply can realize the waveform of the expectation that will apply at Vout.

Such as, can console switch T1, T2 with make the voltage on substrate 110,210 surface be generally negative and periodic voltage pulse close to and/or only slight beyond positive voltage reference.The magnitude of voltage of substrate 110,210 surface is the value defining ion energy, and its feature can in ion energy distribution function (IEDF).In order to realize the voltage expected in substrate 110,210 surface, the pulse of Vout be generally rectangle and there is width be long enough to go out of short duration positive voltage at substrate 110,210 surface induction, the electronics of abundance to be attracted to substrate 110,210 surface, thus realize the ion energy of voltage and the correspondence expected.

Close and/or just over positive voltage reference periodic voltage pulse can have the minimum time limited by the switching capability of switch T1, T2.The roughly negative part of described voltage is extensible, as long as described voltage is not building up to the level damaging switch.Meanwhile, the length of the negative part of voltage should exceed the ion transit time.

Vbus in this embodiment defines the pulse amplitude measured at Vout, which defines voltage and the ion energy of substrate surface.Again can be coupled to ion energy control part with reference to figure 2, Vbus briefly, described ion energy control part can by for apply to Vbus DC signal or time become the DC power supply of waveform and realize.

Can modulate pulsewidth, pulse shape and/or two signals V2, V4 mutual delay to reach the expectation waveform (being also referred to as the periodic voltage function of amendment herein) at Vout, and the voltage being applied to Vbus can affect the characteristic of pulse.In other words, voltage Vbus can affect the relative phase of pulsewidth, pulse shape and/or signal V2, V4.Such as, concise and to the point reference diagram 4, shows two drive signal waveform (as V2 and the V4) timing diagrams illustrating and can be applied to T1 and T2, to produce the periodic voltage function gone out as shown in Figure 4 at Vout.In order to be modulated at the pulse shape (such as, in order to realize the minimum time of the pulse of Vout, also reaching the peak value of pulse) of Vout, the timing of two gate drive signals V2, V4 can be controlled.

Such as, two gate drive signals V2, V4 can be applied to switch block T1, T2, thus the time T-phase ratio and between pulse, can be shorter in the time of each pulse of Vout applying, but be long enough to go out positive voltage at substrate 110,210 surface induction, electronics to be attracted to substrate 110,210 surface.In addition, having been found that the gate voltage level by changing between pulse, the slope (such as, in order to realize the substantially invariable voltage of substrate surface between the pulses) of the voltage being applied to Vout between the pulses can being controlled.In certain operations pattern, the repetition rate of grid impulse is approximately 400kHz, but this repetition rate must be able to change according to the difference of application.

Although do not require, but in practice, according to based on the modeling of actual execution mode and refinement, the waveform that can be used for producing (definition) ion energy distribution expected can be defined, and described waveform can be stored (such as, in the Waveform storage portion described with reference to figure 1, the sequence as voltage level).In addition, in many embodiments, waveform (such as, not needing the feedback from Vout) can directly be produced; Therefore, the less desirable aspect (such as, setting-up time) of feedback control system is avoided.

Refer again to Fig. 3, Vbus can be modulated to control ion energy, and the waveform stored may be used for control gate drive singal V2, V4, to realize the expectation pulse amplitude at Vout place, make pulsewidth minimize simultaneously.Again, this can according to can modeling or enforcement and the special characteristic of transistor empirically set up come.Such as, with reference to figure 5, show that Vbus changes in time, the voltage on substrate 110,210 surface changes in time and the diagram of the ion energy distribution of correspondence.

Diagram in Fig. 5 shows the monotype of console switch mode bias power supply 106,206, and it achieves the ion energy distribution can concentrated in specific ion.As shown, in order to realize concentrating of single ion energy in this example, keep the voltage being applied to Vbus constant, control is simultaneously applied to the voltage of V2 and V4 (such as, utilize the drive singal shown in Fig. 3), to produce pulse at the output of switching mode bias supply 106,206, it achieves the ion energy distribution of the correspondence shown in Fig. 5.

Go out as shown in Figure 5, the electromotive force on substrate 110,210 surface is generally negative, to attract bombardment and the ion of etch substrate 110,210.The cycle short pulse that (by applying pulse to Vout) is applied to substrate 110,210 has the size defined by the electromotive force being applied to Vbus, and these pulses result in the minor variations of the electromotive force of substrate 110,210 (such as, close to just or slightly positive electromotive force), electronics is attracted to substrate surface by this, to realize the negative potential substantially along substrate 110,210 surface.Go out as shown in Figure 5, the constant voltage being applied to Vbus achieves the concentrating of single ionic flux at specific ion energy; Therefore, can by simply Vbus being set as that certain electrical potential selects specific ion bombarding energy.Under other operator scheme, what can create two or more ion energies be separated concentrates (such as, see Figure 49).

Those skilled in the art will recognize that, without the need to power supply is restricted to switched-mode power supply, and so, also the output of controllable power is to affect certain ion energy.So, when considering when not compensating with ionic current or ionic current combines, the output of power supply (no matter being switched-mode power supply or other power supply) also can be called as supply voltage V _pS.

With reference to figure 6, such as, the diagram producing in ion energy distribution and have the bimodal operator scheme of two detached peakses is shown.As shown, in this operating mode, substrate stands the level of two obvious voltages and recurrent pulse, and therefore creates concentrating of two ion energies be separated.As shown, concentrate to realize two obvious ion energies, at the voltage alternation between two levels that Vbus applies, and each level defines the energy level that two ion energies are concentrated.

Although Fig. 6 shows two voltages (such as, Figure 48) of the substrate 110,210 of alternation after each pulse, this is inevitable is not required.Such as, under other operator scheme, relative to the voltage being applied to Vout, switch (such as to the voltage being applied to V2 and V4, use the drive singal shown in Fig. 3), to make induced voltage at substrate surface after two or more pulse from the first voltage to the second voltage (vice versa) alternation (such as, Figure 49).

In the prior art, attempted the combination of (being produced by waveform generator) two waveforms to be applied to linear amplifier and the combination of two waveforms after amplification has been applied to substrate to realize multiple ion energy.But the method is much more complicated than the method described with reference to figure 6, and need expensive linear amplifier and waveform generator.

Following reference diagram 7A and 7B, respectively illustrates the diagram of the actual direct ion energy measurement in the plasma carried out corresponding with the monoenergetic of the DC voltage being applied to Vbus and two level modulation.As illustrated in figure 7 a, in response to the fixed voltage (such as, going out as shown in Figure 5) being applied to Vbus, ion energy distribution concentrates near 80eV.And in figure 7b, in response to two level adjustment (such as, going out as shown in Figure 6) of Vbus, two ion energies be separated are concentrated and are present near 85eV and 115eV.

Following reference diagram 8, shows the block diagram that another embodiment is shown of the present invention.As shown, switched-mode power supply 806 is coupled to controller 812, ion energy control assembly 820 and substrate support portion 808 via arc-detection parts 822.Controller 812, switched-mode power supply 806 and ion energy control assembly 820 jointly work and apply energy to substrate support portion 808, to realize (definition) ion energy distribution expected on time averaging basis on the surface of substrate 810.

Tout court with reference to figure 9A, the cycle that such as shows is about the periodic voltage function of 400kHz, and it is modulated by the sinusoidal modulation function of about 5kHz during multiple cycles of described periodic voltage function.Fig. 9 B is the exploded view of the part of the periodic voltage function circulated in Fig. 9 A, and Fig. 9 C show obtained by the Sine Modulated of periodic voltage function, on time averaging basis, the distribution of ion energy that obtains.And Fig. 9 D shows the direct ion energy measurement of the reality of carrying out in the plasma of that obtain when periodic voltage function is modulated by sinusoidal modulation function, time averaging IEDF.As discussed further herein, (definition) ion energy distribution time averaging basis realizing expect can realize by changing the modulating function being applied to periodic voltage simply.

With reference to Figure 10 A and 10B as another example, modulated the periodic voltage function of 400kHz by the saw tooth modulation function of about 5kHz, to reach the ion energy distribution shown in Figure 10 C on time averaging basis.As shown, except the periodic voltage function in Figure 10 is by sawtooth function but not SIN function is modulated, the periodic voltage function used in conjunction with Figure 10 is identical with Fig. 9.

Will be appreciated that, Fig. 9 C and the ion energy distribution function shown by Figure 10 C do not represent the instantaneous ion Energy distribution on substrate 810 surface, but the time averaging ion energy of phase antirepresentation.Such as, with reference to figure 9C, in a certain particular moment, ion energy distribution will be the subset of that exist on the whole periodic process of modulating function, shown ion energy distribution.

It should also be appreciated that modulating function needs not to be fixed function, also need not be fixed frequency.In some cases, such as, may expect to carry out modulation to realize specific, time averaging ion energy distribution to the periodic voltage function with one or more specific modulation period of a function, and then modulation be carried out to realize another time averaging ion energy distribution to the periodic voltage function in the cycle with one or more another modulating function.Under many circumstances, can be favourable to this change of (function of voltage modulation period) modulating function.Such as, if need specific ion Energy distribution to etch specific geometric configuration or to be etched through certain material, just can use the first modulating function, and then, another modulating function can be used subsequently to realize different etch geometries or to be etched through another material.

Similarly, periodic voltage function (such as, Vout in the parts of the 400kHz in Fig. 9 A, 9B, 10A and 10B and Fig. 4) need not strictly fix (such as, the shape of periodic voltage function and frequency can change), but its frequency was determined by the transit time of the ion of indoor usually, to make indoor ion by the voltage influence being applied to substrate 810.

Back with reference to figure 8, controller 812 provides drive control signal 832 ' and 832 to switched-mode power supply 806 ", make switched-mode power supply 806 produce periodic voltage function.The parts that switched-mode power supply 806 can go out as shown in Figure 3 realize (such as, creating periodic voltage function illustrated in fig. 4), but must expect utilizing other switch configuration.

Generally speaking, ion energy control assembly 820 plays the effect applying modulating function (it is produced in conjunction with switched-mode power supply 806 by controller 812) to periodic voltage function.As shown in Figure 8, ion energy control assembly 820 comprises the modulation controller 840, IEDF function memory 848, user interface 846 and the power supply unit 844 that communicate with self-defined IEDF portion 850.Will be appreciated that, illustrate that these parts are intended to expressive function parts, in fact described functional part can be realized by identical or different parts.

Modulation controller 840 in this embodiment controls power supply unit 844 (and exporting 834) based on the data of definition modulating function usually; and power supply unit 844 (control signal 842 based on from modulation controller 840) produces modulating function 834, modulating function 834 is applied to the periodic voltage function produced by switched-mode power supply 806.User interface 846 in this embodiment is configured to enable user select the predefined IEDF function be stored in IEDF function memory 848, or defines self-defining IEDF in conjunction with self-defining IEDF parts 850.

In many embodiments, power supply unit 844 comprises DC power supply (such as, DC switched-mode power supply or linear amplifier), it by modulation voltage (such as, the DC voltage of change) be applied to switched-mode power supply (Vbus of the switched-mode power supply such as, shown in Fig. 3).In these embodiments, modulation controller 840 controls the voltage level exported by power supply unit 844, makes power supply unit 844 apply the voltage conformed to modulating function.

In some embodiments, IEDF function memory 848 comprises and each the corresponding multiple data set in multiple IEDF distribution function, and user interface 846 enables user select (definition) IEDF function expected.With reference to Figure 11, such as, right row show the exemplary IEDF function that can be used for selecting for user.And left column shows relevant modulating function, described modulating function is applied to periodic voltage function to realize corresponding IEDF function in conjunction with power supply unit 844 by modulation controller 840.Will be appreciated that, the IEDF function shown in Figure 11 is only exemplary, also can be used for selecting other IEDF function.

Self-defining IEDF parts 850 play the effect enabling user be defined (definition) ion energy distribution function of expectation by user interface 846 usually.In some embodiments, such as, self-defining IEDF parts 850 enable user determine the value of the special parameter defining ion energy distribution.

Such as, one or more functions that self-defining IEDF parts 850 make it possible to the IEDF combined between these energy levels of definition according to the relative flux level (such as, according to the percentage of flux) in high level (high IF), middle level (middle IF) and low level (low IF) define IEDF function.In many cases, only high IF, IEDF function between low IF and these level are just enough to definition IEDF function.As particular example, user can utilize and contribute the sinusoidal IEDF between level to ask the 1200eV of 20% contribution level, 30% to contribute the 700eV of level in 20% contribution level (contribution level) (contribution to total IEDF) and 30%.

It will also be appreciated that, self-defining IEDF portion 850 can enable user fill form with the list of one or more (such as, many) energy levels and each energy level of correspondence and the percentage contribution of IEDF.And in another alternate embodiment, can expect, self-defining IEDF parts 850 enable user graphically produce (definition) IEDF of expectation in conjunction with user interface 846 by presenting the graphical tool enabling user draw (definition) IEDF of expectation to user.

In addition it will also be appreciated that, IEDF function memory 848 and self-defined IEDF parts 850 interactive operation can be selected predefined IEDF function to enable user and then change predefined IEDF function, to produce the self-defining IEDF function of being derived by predefined IEDF function.

Once define IEDF function, the data of (definition) IEDF function that definition is just expected by modulation controller 840 are converted to the control signal 842 controlling power supply unit 844, realize the modulating function corresponding with (definition) IEDF expected to make power supply unit 844.Such as, control signal 842 controls power supply unit 844 and exports to make power supply unit 844 voltage defined by modulating function.

Following with reference to Figure 12, it is the block diagram of the embodiment of the ionic current illustrated in ionic current compensating unit 1260 compensation plasma body room 1204.Applicant has been found that under more high level, and the ionic current of indoor more high level affects the voltage of substrate surface, and result, ion energy distribution is also affected.Tout court with reference to figure 15A-15C, such as, the voltage waveform when voltage waveform appears at substrate 1210 or crystal column surface and the relation with IEDF thereof is shown.

More specifically, Figure 15 A shows as ionic current I _iequal the periodic voltage function on substrate 1210 surface during offset current Ic; Figure 15 B shows as ionic current I _ibe greater than the voltage waveform on substrate 1210 surface during offset current Ic; And Figure 15 C shows as ionic current I _ibe less than the voltage waveform of substrate surface during offset current Ic.

As shown in Figure 15 A, work as I _iduring=Ic, the expansion 1470 of ion energy is narrower than relatively works as I shown in Figure 15 B _ithe even expansion 1472 of ion energy during >Ic or shownly in figure 15 c work as I _ithe even expansion 1474 of ion energy during <Ic.Therefore, ionic current compensating unit 1260 when ionic current is higher (such as, effect by counterion electric current) realize the narrow expansion of ion energy, and achieve the even expansion 1572,1574 controlled (such as, when expecting that there is ion energy expansion) of ion energy.

As shown in Figure 15 B, compensate there is no ionic current and (work as I _i>Ic) when, between the positive part of periodic voltage function, the voltage of substrate surface becomes negative smaller in ramp type mode, this generates wider ion energy expansion 1572.Similarly, the level of offset current is increased until exceed the ionic current (I gone out as shown in Figure 15 C when utilizing ionic current to compensate _iduring level <Ic), between the positive part of periodic voltage function, the voltage of substrate surface becomes more negative in ramp type mode, and produces wider uniform ion energy spread 1574.

Back with reference to Figure 12, ionic current compensating unit 1260 can be implemented as independently annex, and it can be added to switched-mode power supply 1206 and controller 1212 alternatively.In other embodiments, (such as, as shown in Figure 13), ionic current compensating unit 1260 can with the shell 1366 of other parts described herein (such as, switched-mode power supply 106,206,806,1206 and ion energy control assembly 220,820) share common.In this embodiment, the periodic voltage function being provided to plasma chamber 1204 can be called as modified periodic voltage function, because it comprises the periodic voltage function being compensated amendment by the ionic current from ionic current compensating unit 1260.Controller 1212 can compensate not sampling to voltage in the same time of the electrical node place of the output combination of 1260 at switched-mode power supply 1206 and ionic current.

As shown in Figure 13, show exemplary ionic current compensating unit 1360, it comprises the current source 1364 of the output 1336 being coupled to switched-mode power supply and is coupled to current source 1364 and the current controller both output 1,336 1362.Figure 13 also show plasma chamber 1304, and plasma indoor have capacitive element C1, C2 and ionic current I _i.Go out as shown in the figure, C1 represent with can include but not limited to insulating material, substrate, the natural capacity (being also referred to as effective capacitance herein) of parts that the room 1304 of substrate support portion and e-chuck is associated, and C2 represents sheath layer capacitance and stray capacitance.In this embodiment, to plasma chamber 1304 provide and at V ₀locate measurable periodic voltage function and can be called as modified periodic voltage function, because it comprises the periodic voltage function being compensated Ic amendment by ionic current.

Sheaths (being also referred to as plasma sheath herein) be in plasma close to the layer of substrate surface and may be plasma processing chamber there is high density cation and the wall of therefore overall superfluous positive charge.The surface of sheaths contact has dominant negative electrical charge usually.Sheaths relies on than cation velocity of electrons and occurring faster, therefore causes the electronics of more vast scale to arrive substrate surface or wall, therefore makes sheaths exhaust electronics.Sheath layer thickness (λ _sheaths) be the function of plasma characteristics (such as, plasma density and plasma temperature).

It should be noted that because of the C in embodiment for this reason ₁intrinsic (the being also referred to as herein effectively) electric capacity of the parts be associated with room 1304, so it is the accessed electric capacity that the gain being added to process controls.Such as, some art methods utilize linear amplifier to be coupled to by bias supply to have on the substrate of blocking capacitor, and then utilize the monitoring voltage at blocking capacitor two ends to control its linear amplifier as feedback.Although in many embodiments disclosed herein, switched-mode power supply can be coupled to substrate support portion by capacitor, owing to not needing the FEEDBACK CONTROL using blocking capacitor in several embodiment of the present invention, so need not do like this.

The exemplary voltage (such as, modified periodic voltage function) that the Vo place shown in Figure 13 is shown with reference to reference Figure 14, Figure 14 while Figure 13.In operation, the voltage at Vo place monitored by current controller 1362, the ionic current as shown in the formula (as shown in Figure 14) during counting period t:

I_{I} = C_{1} \frac{dVo}{dt}

(equation 1)

Ionic current I _iwith natural capacity (being also referred to as effective capacitance) C ₁in any one or both can be time become.Due to C ₁be substantially invariable for given instrument and be measurable, so only need monitoring Vo to realize the uninterrupted control of offset current.As mentioned above, in order to obtain monoenergetic distribution (such as, going out as shown in figure 15 a) of more polyion energy, current controller controls current source 1364 to make I _cwith I _isubstantially equal (or in replacement scheme, according to equation 2 and I _irelevant).According to the method, even if when ionic current reaches the level of the voltage affecting substrate surface, the narrow expansion of ion energy can also be kept.And in addition, if necessary, the expansion of ion energy can be controlled as shown by Figure 15 B and 15C, to make to produce extra ion energy at substrate surface.

Equally, figure 13 illustrates feedback line 1370, it can use in conjunction with control ion energy distribution.Such as, the value of the Δ V (being also called as voltage step or Part III 1406 herein) shown in Figure 14 represents instantaneous ion energy, and may be used for the part as feedback control loop in many embodiments.In one embodiment, according to equation formula 4, V is relevant to ion energy for voltage step Δ.In other embodiments, peak-to-peak voltage V _pPcan be relevant to instantaneous ion energy.Alternatively, peak-to-peak voltage V _pPwith the slope dV of Part IV 1408 ₀difference between the product that/dt is multiplied by time t can (such as, V relevant to instantaneous ion energy _pP– dV ₀/ dtt)

Following reference Figure 16, shows the one exemplary embodiment of current source 1664, and it may be used for realizing the current source 1364 with reference to described in Figure 13.In this embodiment, the controlled negative DC voltage source be connected with series reactor L2 plays the effect of current source, but it will be understood to those of skill in the art that in view of this specification, can realize current source by other parts and/or configuration.

Figure 43 shows an embodiment of the method for the ion energy distribution of the ion on the surface controlling collision substrate.Method 4300 starts by applying modified periodic voltage function 4302 (the modified periodic voltage function 4402 see in Figure 44) to the substrate support at plasma processing chamber inner support substrate.Can via at least two ' knobs ' (such as ionic current compensation I _c(see the I in Figure 44 _c4404) and supply voltage V _pS(supply voltage 4406 see in Figure 44) controls modified periodic voltage function.Example components for generation of supply voltage is the switched-mode power supply 106 in Fig. 1.In order to help to explain supply voltage V _pS, when it is shown in measurement in this article, be not coupled to ionic current and ionic current compensation.Then I is compensated at ionic current _cthe first numerical value and described second value place sampling 4304 is carried out to modified periodic voltage function.I is compensated for ionic current _ceach numerical value choose at least two samples of the voltage of modified periodic voltage function.Perform sampling 4304 to realize ionic current I _iwith sheath layer capacitance C _sheathscalculating 4306 (or determination) 4306.This determine to relate to find ionic current compensate I _cif be applied to substrate support (maybe when being applied to this substrate support) and will narrow (such as, minimum) ion energy distribution function (IEDF) width be produced.Calculate 4306 samplings 4304 that can also comprise alternatively based on the waveform of modified periodic voltage function and determine voltage step Δ V (being also referred to as the Part III 1406 of modified periodic voltage function).Voltage step Δ V can be relevant to the ion energy of the ion on the surface of arrival substrate.When finding ionic current I first _itime, voltage step Δ V can be ignored.The details of sampling 4304 and calculating 4306 will be provided in the discussion of following Figure 30.

Once known ion electric current I _iwith sheath layer capacitance C _sheaths, method 4300 just can move on to relating to setting and monitoring the ion energy of IEDF and the method 3100 of shape (such as, width) of Figure 31.Such as, how the change that Figure 46 shows supply voltage can affect the change of ion energy.Especially, the size of shown supply voltage reduces, thus causes the size of the reduction of ion energy.In addition, Figure 47 shows, and when considering narrow IEDF 4714, compensates I by regulating ionic current _ciEDF is broadened.Alternatively or concurrently, method 4300 can perform various tolerance as described by with reference to figure 32-41, and it utilizes ionic current I _i, sheath layer capacitance C _sheathswith the waveform other side of modified periodic voltage function.

Except arranging ion energy and/or IEDF width, the adjustable modified periodic voltage function 4308 of method 4300 is to keep ion energy and IEDF width.Especially, the ionic current compensation I to being provided by ionic current compensating unit can be performed _cadjustment and adjustment 4308 to supply voltage.In certain embodiments, by the bus voltage V of power supply _bus(such as, the bus voltage V of Fig. 3 _bus) control supply voltage.Ionic current compensates I _ccontrol IEDF width, and supply voltage controls ion energy.

Regulate after 4308 at these, again can sample to modified periodic voltage function 4304, and can again perform ionic current I _i, sheath layer capacitance C _sheathswith the calculating 4306 of voltage step Δ V.If ionic current I _ior voltage step Δ V is different from defined numerical value (or in replacement scheme, desired numerical value), then adjustable ionic current compensates I _cand/or supply voltage 4308.Sampling 4304 can be there is, calculate the circulation of 4306 and adjustment 4308, to keep ion energy eV and/or IEDF width.

Figure 30 shows another embodiment of the method for the ion energy distribution of the ion on the surface controlling collision substrate.In certain embodiments, as mentioned above, narrow IEDF width (such as, minimum IEDF width, or in replacement scheme, ~ 6% full width at half maximum) can be expected to realize.So, method 3000 can provide modified periodic voltage function to room to substrate support, making there is constant underlayer voltage in the surface of substrate, and therefore plasma arc voltage.This accelerates with the ion of the voltage of substantial constant to sheaths two ends then, and therefore make ion can collide substrate with substantially the same ion energy, it provides narrow IEDF width then.Such as, in Figure 45, the visible ionic current that regulates compensates I _cthe underlayer voltage V between pulse can be caused _subthere is voltage that is constant or substantial constant, therefore cause IEDF to narrow.

Suppose without stray capacitance (see the periodic voltage function (V in Figure 45 ₀) last five cycles), ionic current compensate I _cequal ionic current I _itime achieve this modified periodic voltage function.In replacement scheme, at consideration stray capacitance C _spuiouswhen, according to equation 2, ionic current compensates I _cwith ionic current I _irelevant:

(equation 2)

Wherein, C ₁effective capacitance (such as, with reference to the natural capacity described in figure 3 and Figure 13).Effective capacitance C ₁can to change in time or constant.For the object of present disclosure, narrow IEDF width can at I _i=I _ctime or in replacement scheme when meeting equation 2 exist.Figure 45-50 uses nomenclature (nomenclature) I _i=I _c, but it should be understood that these equatioies are only the simplification of equation 2, and the equation therefore used in the alternative Figure 45-50 of equation 2.Stray capacitance C _spuiousthe accumulation electric capacity of plasma chamber, as by power supply finding.Figure 45 illustrates eight cycles.

Method 3000 can start to substrate support (such as, substrate support 108 in Fig. 1) apply modified periodic voltage function (the modified periodic voltage function such as, shown in Figure 14 or the modified periodic voltage function 4402 in Figure 44) 3002.Sampling 3004 can be carried out by voltage in two or more moment to modified periodic voltage function, and according to this sampling, the slope dV at least partially of modified periodic voltage period of a function can be calculated ₀/ dt (slope of the part such as, between pulse or Part IV 1408) 3006.In certain moment before decision-making 3010, effective capacitance C can be accessed ₁(the natural capacity C such as, in Figure 13 ₁with the natural capacity C10 in Fig. 3) the numerical value (such as, inputting access from memory or from user) 3008 previously determined.Based on slope dV ₀/ dt, effective capacitance C ₁i is compensated with ionic current _c, I can be compensated for ionic current as follows _ceach Numerical evaluation function f (equation 3):

f (I_{c}) = \frac{{dV}_{0}}{dt} - \frac{I_{C}}{C_{1}} = 0

(equation 3)

If function f is true, then ionic current compensates I _cequal ionic current I _i, or in replacement scheme, make equation 2 be true, and realized narrow IEDF width 3010 (such as, see Figure 45).If function f is not true, then ionic current can be regulated further to compensate I _c3012, until function f is true.Check that the another way of this situation is that adjustable ionic current compensates I _c, until its coupling ionic current I _i, narrow IEDF width will be there is at this place in (or in replacement scheme, meeting the relation of equation 2).Can see in Figure 45 to ionic current compensate this adjustment of Ic and IEDF produce and narrow.Can (such as, in memory) ion storage electric current I in storage operation 3014 _iic is compensated with the ionic current of correspondence.Ionic current I _ccan as effective capacitance C ₁equally change in time.

When meeting equation 3, ionic current I _iknown (because I _c=I _ior because equation 2 is true).Therefore, method 3000 realizes ionic current I _ireal-time long-range and non-invasive measurement, and do not affect plasma.This causes some novelty tolerance, such as with reference to those tolerance (such as, the remote monitoring of article on plasma volume density and the remote failure of article on plasma body source detect) described in Figure 32-41.

At adjustment 3012 offset current I _ctime, ion energy will be probably wider than delta function, and ion energy will be similar to the ion energy of Figure 15 B, Figure 15 C or Figure 44.But, once find offset current I _cmeet equation 2, IEDF just will occur, as shown in the right part of Figure 15 A or Figure 45-for having narrow IEDF width (such as, minimum IEDF width).This is because work as I _c=I _itime (or alternatively when equation 2 is true time), the voltage between the pulse of modified periodic voltage function causes sheaths or the underlayer voltage of substantial constant, and the ion energy of therefore substantial constant.In figures 4-6 can, underlayer voltage 4608 comprises the pulse between constant potential portion.These pulses have the so short duration so that it is negligible on the impact of ion energy and IEDF, and therefore underlayer voltage 4608 is taken as is substantial constant.

Further details about each method step in the method step shown in Figure 30 is hereafter provided.In one embodiment, modified periodic voltage function can have the waveform as the waveform shown in Figure 14 and can comprise Part I (such as, Part I 1402), Part II (such as, 1404), Part III (such as, Part III 1406) and Part IV is (such as, Part IV 1408), wherein Part III can have voltage step Δ V, and Part IV can have slope dV ₀/ dt.Slope dV ₀/ dt can be positive and negative or zero.Modified periodic voltage function 1400 also can be described to have the pulse comprising Part I 1402, Part II 1404 and Part III 1406, and the part (Part IV 1408) between pulse.

Modified periodic voltage function can be measured as the V in Fig. 3 ₀and the modified periodic voltage function 4402 that can appear as in Figure 44.Modified periodic voltage function 4402 passes through supply voltage 4406 (being also referred to as periodic voltage function) and ionic current to be compensated 4404 and combines and produce.Supply voltage 4406 primary responsibility produces and makes the pulse shaping of modified periodic voltage function 4402, and ionic current compensates 4404 primary responsibility produces and to make between pulse partially-formed, and it is the voltage that tilts of straight line normally.Increasing ionic current compensation Ic causes the size of the slope of the part between pulse to reduce, seen in Figure 45.The size reducing supply voltage 4606 causes the reduction of the peak-to-peak voltage of the size of the amplitude of pulse and modified periodic voltage function 4602, seen in Figure 46.

When power supply is switched-mode power supply, switch Figure 44 10 of the first switch T1 and second switch T2 can be applied.Such as, the first switch T1 can be embodied as the switch T1 in Fig. 3, and second switch T2 can be embodied as the second switch T2 in Fig. 3.Two switches are depicted as has identical switching time, but out-phase 180 °.In other embodiments, switch can have the slight phase deviation of all slight phase deviation and so on as shown in Figure 4.When the first switch T1 opens, supply voltage is drawn to largest amount, and it is negative value in Figure 44, because power supply has negative bus voltage.Second switch T2 closes during this cycle, isolates with ground to make supply voltage 4406.When switch oppositely (reverse) time, supply voltage 4406 close to and just over (pass) greatly.In the embodiment illustrated, there are two pulse durations, but this not necessarily.In other embodiments, pulse duration can be identical for all cycles.In other embodiments, pulse duration can change in good time or modulate.

Modified periodic voltage function may be used on substrate support 3002, and before modified periodic voltage function arrives substrate support in the end one can access point place sampling 3004 be V ₀(such as, between switched-mode power supply and effective capacitance).The periodic voltage function (or the supply voltage 4406 in Figure 44) of unmodified can be derived from the power supply of the switched-mode power supply 1206 in such as Figure 12 and so on.Ionic current in Figure 44 compensates the current source that 4404 can be derived from the ionic current compensating unit 1260 in such as Figure 12 or the ionic current compensating unit 1360 in Figure 13.

Sampling 3004 can be carried out to a part for modified periodic voltage function or whole modified periodic voltage function.Such as, can sample by Part IV (such as, Part IV 1408).Sampling 3004 can perform between power supply and substrate support.Such as, in FIG, sampling 3004 can be performed between switched-mode power supply 106 and support portion 108.Such as, in FIG, sampling 3004 can be performed between switched-mode power supply 106 and support portion 108.In figure 3, sampling 3004 can be performed between inductor L1 and natural capacity C10.In one embodiment, can at V between electric capacity C3 and natural capacity C10 ₀place performs sampling 3004.Because the element (R2, R3, C1 and C2) of natural capacity C10 and expression plasma can not access for real-time measurement, therefore the left side of usual natural capacity C10 in figure 3 performs sampling 3004.Although natural capacity C10 does not measure usually during processing, its usual known constant, and therefore can arrange during manufacture.Meanwhile, in some cases, natural capacity C10 can change in time.

Although in certain embodiments, only need two samples of modified periodic voltage function, in other embodiments, hundreds of, a thousands of or thousands of sample can be chosen for each cycle of modified periodic voltage function.Such as, sample rate can be greater than 400kHz.These sample rates realize the more accurate and detailed monitoring to modified periodic voltage function and shape thereof.In this identical texture (vein), the more accurate comparison to waveform is allowed to the more in-depth monitoring of periodic voltage function: between different cycles, between different technology conditions, between different process, between different chamber, not between homology etc.Such as, with these sample rates, can distinguish the first, second, third and fourth part 1402,1404,1406,1408 of the periodic voltage function shown in Figure 14, this can be impossible with traditional sampling rate.In certain embodiments, comparatively high sampling rate realizes voltage step Δ V and slope dV ₀the parsing of/dt, this is impossible in the art.In certain embodiments, can sample to a part for modified periodic voltage function, and other parts not sampled.

Can based on the repeatedly V carried out in time t (such as, Part IV 1408) period ₀measure slope dV ₀/ dt carries out calculating 3006.Such as, linear fit can be performed so that a line is fitted to V ₀value, the slope of wherein said line provides slope dV _o/ dt.In another example, the beginning of time t (such as, Part IV 1408) in fig. 14 and the V of end can be determined ₀value, and can between these two somes matching line, the slope of wherein said line is given dV _o/ dt.These are only the slope dV of the part that can calculate between pulse _otwo kinds of modes in many modes of/dt.

Decision-making 3010 can be for by IEDF be tuned to the part of iterative cycles of narrow width (such as, minimum widith, or in replacement scheme, 6% full width at half maximum).Equation 3 only compensates Ic at ionic current and equals ionic current I _i(or in replacement scheme, according to equation 2 and I _irelevant) when remain true, only when there is constant underlayer voltage and therefore constant and substantially single ion energy (narrow IEDF width) occurs in it.Visible constant underlayer voltage 4608 (V in figures 4-6 can _sub).Therefore, ionic current I _ior alternatively ionic current compensation Ic can use in equation 3.

Alternatively, can sample to two numerical value along Part IV 1408 (being also referred to as the part between pulse) for period 1 and second round, and the first slope and the second slope can be determined for each cycle respectively.According to these two slopes, can determine that ionic current compensates Ic, expect that ionic current compensates Ic and makes equation 3 be true for the 3rd (but not yet measuring) slope.Therefore, ionic current I can be estimated _i, estimate ionic current I _icorresponding to narrow IEDF width.These are only can determine narrow IEDF width and can find that corresponding ionic current compensates the ionic current I of Ic and/or correspondence _imany modes in two kinds of modes.

The adjustment 3012 ionic current being compensated to Ic can relate to increase or reduce ionic current compensation Ic, and unrestricted to each step-length regulated.In certain embodiments, in equation 3, the symbol of function f can be used for determining that increasing or reduce ionic current compensates.If symbol is negative, then can reduce ionic current compensate Ic, and plus sign can indicate need increase ionic current compensate Ic.

Once identify that ionic current compensates Ic and equals ionic current I _i(or in other scheme, relevant to it according to equation 2), method 3000 just can proceed to further set-point operation (see Figure 31) or remote chamber and source policer operation (see Figure 32-41).Described further set-point operation can comprise the distribution or IEDF width (also see Figure 47) that arrange ion energy (also see Figure 46) and ion energy.Source and room monitoring can comprise that monitoring plasma volume density, source supply are abnormal, plasma arc and other.

In addition, method 3000 is circulated back to sampling 3004 alternatively so that continuously and (or in replacement scheme, periodically) upgrades ionic current and compensate Ic.Such as, when considering that current ionic current compensates Ic, sampling 3004, calculating 3006, decision-making 3010 can be performed periodically and regulate 3012, to guarantee to continue to meet equation 3.Meanwhile, if upgrade the ionic current meeting equation 3 to compensate Ic, then also renewable ionic current I _iand 3014 can be stored through upgrading numerical value.

Although method 3000 can find and arrange ionic current compensate Ic thus equal ionic current I _i, or in replacement scheme, meet equation 2, but not by ionic current I _c(or in replacement scheme, by ionic current I when being set to this numerical value _cbefore being set to this numerical value), can determine that the ionic current realized needed for narrow IEDF width compensates the numerical value of Ic.Such as, Ic is compensated by applying the first ionic current for the period 1 ₁and the first slope dV of the voltage between ranging pulse ₀₁/ dt, and by compensating Ic for applying the second ionic current second round ₂and the second slope dV of the voltage between ranging pulse ₀₂/ dt, can determine to compensate Ic with the 3rd ionic current ₃the 3rd slope dV be associated ₀₃/ dt, wherein, expects that equation 3 is true.3rd ionic current compensates Ic ₃can be if apply the ionic current producing narrow IEDF width to compensate.Therefore, can only determine to meet equation 3 by the single adjustment compensated ionic current and therefore with ionic current I _icorresponding ionic current compensates Ic.Then method 3000 can move on to the method described in Figure 31 and/or Figure 32-41, and never by ionic current I _cbe set to realize the numerical value needed for narrow IEDF width.This embodiment can be performed to increase tuned speed.

Figure 31 shows the method for arranging IEDF width and ion energy.Described method is derived from the method 3000 shown in Figure 30, and the arbitrary path can chosen in left hand path 3100 (being also referred to as IEDF branch road) or right hand path 3101 (being also referred to as ion energy branch road), it needs to arrange IEDF width and ion energy respectively.Ion energy eV is directly proportional to the Part III 1406 of the modified periodic voltage function 1400 of voltage step Δ V or Figure 14.Relation between ion energy eV and voltage step Δ V can be written as equation 4:

eV = ΔV = \frac{C_{1}}{C_{2} + C_{1}}

(equation 4)

Wherein C ₁effective capacitance (such as, chuck electric capacity; Natural capacity C10 in Fig. 3; Or the natural capacity C1 in Figure 13), and C ₂sheath layer capacitance (the sheath layer capacitance C2 in sheath layer capacitance C4 or Fig. 3 such as, in Fig. 3).Sheath layer capacitance C ₂can stray capacitance be comprised and depend on ionic current I _i.Voltage step Δ V can be measured as the change of the voltage between the Part II 1404 of modified periodic voltage function 1400 and Part IV 1408.By control and monitoring voltage step Δ V (it is the bus voltage V in supply voltage or such as Fig. 3 _busand so on the function of bus voltage), can control and know ion energy eV.

Meanwhile, IEDF width can be estimated according to equation 5:

(equation 5)

Wherein, be C at C _{series connection}when I be I _i, or be C at C _effectivelywhen I be I _c.Time t is the time between pulse, V _pPbe peak-to-peak voltage, and Δ V is voltage step.

In addition, sheath layer capacitance C ₂can be used in multiple calculating and policer operation.Such as, Debye sheaths distance lambda can be estimated as follows _sheaths:

(equation 6)

Be wherein permittivity of vacuum, and A is the area (or in replacement scheme, the surface area of substrate support) of substrate.In some high voltage applications, equation 6 is written as equation 7:

(equation 7)

In addition, the e field in sheaths can be estimated as sheath layer capacitance C ₂, sheaths distance lambda _sheathswith the function of ion energy eV.Sheath layer capacitance C ₂together with ionic current I _ialso can be used for together determining plasma density n according to equation 8 _e, wherein for the plasma of ionization separately, saturation current I _satwith offset current I _clinear correlation.

I_{sat} = Σ n_{i} q_{i} \sqrt{\frac{{kT}_{e}}{m_{i}}} A \approx n_{e} q \sqrt{\frac{{kT}_{e}}{< m >}} A

(equation 8)

Sheath layer capacitance C can be used ₂with saturation current I _satcalculate the effective mass of the ion at substrate surface place.Plasma density n _e, electric field, ion energy eV, the effective mass of ion and the DC current potential V of substrate in sheaths _dCusually only via the basic plasma parameter of the indirect means monitoring in this area.Present disclosure realizes the direct measurement to these parameters, therefore realizes the more accurately monitoring in real time of article on plasma bulk properties.

Seen in equation 4, sheath layer capacitance C ₂also can be used for monitoring and control ion energy eV, as shown in the ion energy branch road 3101 of Figure 31.Ion energy branch road 3101 selects 3102 and start by receiving the user of ion energy.Then, ion energy branch road 3101 can to supply cycle function of voltage the primary power voltage of switched-mode power supply arrange 3104.In certain moment before the periodic voltage operation 3108 of sampling, also can access ionic current 3106 (such as, from memory access).Can sampling period voltage 3108, and measurement 3110 can be carried out to the measurement of the Part III of modified periodic voltage function.Ion energy I can be calculated according to the voltage step Δ V of modified periodic voltage function (being also referred to as Part III (such as, Part III 1406)) _i3112.Then, ion energy branch road 3101 can determine the ion energy 3114 whether ion energy equals defined, and if like this, then ion energy is in desired set-point place and ion energy branch road 3101 can terminate.If ion energy is not equal to defined ion energy, then ion energy branch road 3101 adjustable source voltage 3116, and again sampling 3108 is carried out to periodic voltage.Then, ion energy branch road 3101 can loop through sampling 3108, measurement 3110, calculating 3112, decision-making 3114 and arranges 3116, until ion energy equals defined ion energy.

Illustrate in the IEDF branch road 3100 of Figure 31 for monitoring and the method for control IEDF width.IEDF branch road 3100 comprises the user receiving IEDF width and selects 3150 and carry out sampling 3152 to current I EDF width.Then, decision-making 3154 determines whether defined IEDF width equals current I EDF width, and if meet decision-making 3152, then IEDF width is (or defined) IEDF width as expected, and IEDF branch road 3100 can terminate.But if current I EDF width be not equal to defined IEDF width, then adjustable ionic current compensates Ic 3156.This determines that 3154 can continue in a looping fashion, until current I EDF width equals defined IEDF width with adjustment 3156.

In certain embodiments, IEDF branch road 3100 can also be implemented to protect desired IEDF shape.Can produce various IEDF shape, and each IEDF shape can be associated with different ions energy and IEDF width.Such as, an IEDF shape can be delta function, and the 2nd IEDF shape can be chi square function.Other IEDF shape can be cup-shaped.The example of visible various IEDF shape in fig. 11.

Knowing ionic current I _iwhen with voltage step Δ V, can for ion energy eV solve equation 4.Control voltage step Δ V is carried out by changing supply voltage (it causes voltage step Δ V to change then).Comparatively large power supply voltage causes voltage step Δ V to increase, and supply voltage reduces to cause voltage step Δ V to reduce.In other words, increase supply voltage and cause comparatively heavy ion energy eV.

In addition, because above system and method is to continually varying feedback loop works, although therefore due to change or the change of plasma that deliberately regulates and cause of plasma source or room condition, desired (or definition) ion energy and IEDF width can be kept.

Although describe Figure 30-41 according to single ionic energy, but those skilled in the art will recognize that, produce and these methods of (or definition) IEDF width (or IEDF shape) desired by monitoring and ion energy can be further used for generation and monitor two or more ion energies, each ion energy has its oneself IEDF width (or IEDF shape).Such as, by first, the 3rd and the period 5 in the first supply voltage V is provided _pSand second, the 4th and the period 6 in second source voltage is provided, two differences can be realized and narrow ion energy (such as, Figure 42 A) for the ion on the surface arriving substrate.Three different electrical power voltages are used to cause three different ions energy (such as, Figure 42 B).By changing the time applying each supply voltage in multiple supply voltage during this period, or applying the number in cycle of each mains voltage level during this period, the ionic flux (such as, Figure 42 C) of different ions energy can be controlled.

More than discuss to have shown how to be compensated with the ionic current provided by ionic current compensating unit by the periodic voltage function provided by power supply and combine, it can be used for the ion energy of the ion controlling the surface arriving substrate during plasma treatment and IEDF width and/or IEDF shape.

Some so far in described control control by using some combinations of the following to realize: (1) fixed waveform (consecutive periods of waveform is identical); (2) there is the waveform of at least two parts, described at least two parts and ion energy and IEDF proportional (Part III such as, shown in Figure 14 and Part IV 1406 and 1408); And (3) high sampling rate (such as, 125MHz), it realizes the accurate monitoring to the different characteristic of waveform.Such as, when prior art (such as linear amplifier sends and waveform like modified periodic voltage function class to substrate), the less desirable change between the cycle makes to be difficult to use those prior art waveforms to characterize ion energy or IEDF width (or IEDF shape).

When linear amplifier is for being biased substrate support, not yet see and carry out the needs of sampling with two-forty, because waveform is inconsistent from cycle to cycle, and therefore the parsing feature (slope of the part such as, between pulse) of waveform will not provide useful information usually.This useful information occurs really when employing fixed waveform, as book is opened seen in content and relevant disclosure.

Fixed waveform disclosed herein and high sampling rate cause more accurate statistical observation to be feasible further.Due to the precision degree that this increases, operation and the treatment characteristic of the plasma in monitoring plasma body source and room can be carried out via the various characteristics of the modified periodic voltage function of monitoring.Such as, the remote monitoring to sheath layer capacitance and ionic current is realized to the measurement of modified periodic voltage function, and can monitor when not knowing room technique or other room details.Some examples only illustrate that described system and method can be used for some modes in source and the non-invasive monitoring of room and a large amount of modes of fault detect so far subsequently.

As the example of monitoring, and with reference to Figure 14, the DC skew of waveform 1400 can represent the health status in plasma source (hereinafter referred to as " source ").In another example, the slope of the top section 1404 (Part II) of the pulse of modified periodic voltage function can be associated with the damping effect in source.It is the another way carrying out monitor source health status based on the aspect of waveform 1400 from the standard deviation of the slope (being depicted as the slope having and equal 0) of the top section 1404 of horizontal line (horizontal).The Part IV 1408 related on the other hand along modified periodic voltage function measure the V that samples ₀the standard deviation of point, and described standard deviation is associated with room ring.Such as, be among continuous impulse, to monitor this standard deviation and described standard deviation increases in time when, this can indicate in room (such as in e-chuck) to there is ring.Ring can be to the bad electrical connection in room or room sign or additionally do not want the sign of inductance or electric capacity.

Figure 32 shows two the modified periodic voltage functions transmitted to substrate support of an embodiment according to present disclosure.When comparing, two the modified periodic voltage function room of can be used for couplings or original position exception or fault detect.Such as, a modified periodic voltage function in two modified periodic voltage functions can be reference waveform, and the second modified periodic voltage function can be selected from plasma processing chamber between alignment epoch.Difference (such as, peak-to-peak voltage V between two modified periodic voltage functions _pPdifference) can be used for calibrate plasma processing chamber.Alternatively, second modified periodic voltage function can compare with reference waveform during processing, and any difference of waveform characteristic (such as, mobile) can indication fault (such as, the difference of the slope of the Part IV 3202 of modified periodic voltage function).

Figure 33 shows the ionic current waveform that can indicate plasma source unsteadiness in plasma density or change.Can to ionic current I _iin fluctuation (all fluctuations as shown in Figure 33) carry out analyzing so that the fault in recognition system and exception.Such as, the cyclic swing in Figure 33 can indicate the low frequency unsteadiness in plasma source (such as, plasma electrical source 102).Ionic current I _iin this fluctuation also can indicate the circulation change of plasma density.This designator is only ionic current I with its denotable possible breakdown or exception _iremote monitoring can be used in many modes of specific advantages a kind of mode.

Figure 34 shows the ionic current I of the modified periodic voltage function with shape aperiodic _i.Ionic current I _ithis embodiment can indicate fluctuation aperiodic and the change of plasma density of such as plasma instability and so on.This fluctuation also can indicate various plasma instability, such as, and the formation of electric arc, parasitic plasma or the drift of plasma density.

Figure 35 shows the modified periodic voltage function of the fault that can indicate in bias supply.The top section (being also referred to as Part II in this article) in the cycle shown by the 3rd illustrates the abnormal behaviour of the ring that can indicate in bias supply (power supply 1206 such as, in Figure 12).This ring can be the instruction to the fault in bias supply.The further analysis identifiable design of ring is helped to the characteristic of the fault identified in power-supply system.

Figure 36 shows can the modified periodic voltage function that changes of dynamic (or non-linear) of electric capacity of indication mechanism.Such as, non-linearly depend on that the stray capacitance of voltage can cause this modified periodic voltage function.In another example, plasma punctures or fault in chuck also can cause this modified periodic voltage function.In each cycle in the cycle shown by three, non-linear in the Part IV 3602 in each cycle can the dynamic change of indication mechanism electric capacity.Such as, the non-linear change indicating sheath layer capacitance, fixes because other component of system capacitance is major part.

Figure 37 shows the modified periodic voltage function that can indicate the change of plasma density.Shown modified periodic voltage function illustrates slope dV ₀dullness in/dt moves, and it can indicate the change of plasma density.These dull movements can provide the direct instruction to expected event (such as, technique etching end point).In other embodiments, these dull movements can indicate and there is not the fault in the technique of expected event.

Figure 38 shows the sampling of the ionic current run for different process, and the drift in its ion current can indication mechanism drift.Each data point can represent the ionic current of given operation, and wherein can accept to limit is user's definition or the volitional check that definition can accept ionic current.Drift (ionic current is shifted onto this by gradually can accept more than restriction) in ionic current can indicate substrate damage to be possible.The monitoring of this type also can be monitored (such as optics omits (opticalomission), thickness measure etc.) with other tradition any amount of and combine.The monitoring of these traditional types except monitoring ion current drift can strengthen existing monitoring and Statisti-cal control.

Figure 39 shows the sampling of the ionic current for different technical parameters.In this diagram, ionic current can be used as the figure of merit figure distinguishing different process and different process characteristic.This data can be used in the exploitation of plasma recipes and process.Such as, 11 process conditions can be tested, produce 11 shown ion current data points, and can be ideal technology by the process choice of generation preferred ion electric current, or as preferred process in replacement scheme.Such as, minimum ionic current can be chosen as ideal technology, and the ionic current be after this associated with selection process can be used as in order to judge the tolerance whether technique performs with preferred processing condition.Substituting except similar traditional figure of merit characteristic (such as speed, selectivity and profile angle) or as similar traditional measure characteristic (such as speed, selectivity and profile angle), this figure of merit figure can be used for naming some non-limiting examples.

Figure 40 shows in room without two that monitor when plasma modified periodic voltage functions.These two modified periodic voltage functions can be compared and use it for sign plasma chamber.In an embodiment, the first modified periodic voltage function can be reference waveform, and the second modified periodic voltage function can be the waveform of current monitor.These waveforms can be chosen without (such as clean in room or preventive maintenance after) when plasma in the process chamber, and therefore the second waveform be used in room is discharged into (or getting back to) produce in before the checking of the electric state to room is provided.

Figure 41 shows two the modified periodic voltage functions that can be used for verifying plasma process.First modified periodic voltage function can be reference waveform, and the second modified periodic voltage function can be the waveform of current monitor.The waveform of current monitor can compare with reference waveform, and any difference can indicate the use undetectable parasitism of traditional method for supervising and/or non-electrical capacitive impedance problems in addition.Such as, on the waveform of Figure 35, seen ring can be detected and can represent the ring in power supply.

Can monitor the arbitrary tolerance in the tolerance shown in Figure 32-41, while method 3000 circulates to upgrade ionic current compensating Ic, ionic current I _iand/or sheath layer capacitance C _sheaths.Such as, at each ionic current I _iafterwards, in Figure 38, choose sampling, method 3000 is capable of circulation gets back to sampling 3004 to determine the ionic current I through upgrading _i.In another example, as the result of policer operation, can expect ionic current I _i, ion energy eV or IEDF width correction.Can carry out correspondence to correct, and method 3000 is capable of circulation gets back to sampling 3004 and compensate Ic to find the new ionic current meeting equation 3.

Those skilled in the art will recognize that, the method shown in Figure 30, Figure 31 and Figure 43 without any need for specific or the operation described order, it is also not limited to by any order illustrating or imply in figure.Such as, can in setting and before monitoring IEDF width and/or ion energy eV, period or monitor tolerance (Figure 32-41) afterwards.

Figure 44 shows each waveform at the difference place in system disclosed herein.Consider shown switching mode 4410, the supply voltage V of the switch block of switched-mode power supply _pS4406 (being also referred to as periodic voltage function herein), ionic current compensate Ic 4404, modified periodic voltage function 4402 and underlayer voltage V _subwhen 4412, IEDF has shown width 4414 (its possibility not drawn on scale) or IEDF shape 4414.This width is called the width of " narrow width " wider than present disclosure.As see, when ionic current compensate Ic 4404 be greater than ionic current I _itime, underlayer voltage V _sub4412 and non-constant.IEDF width 4414 and underlayer voltage V _subvoltage difference between sloping portion between the pulse of 4412 is proportional.

When considering this non-narrow IEDF width 4414, method disclosed herein requires to regulate ionic current to compensate Ic, until I _c=I _i(or in replacement scheme, according to equation 2 and I _irelevant).Figure 45 shows and carry out final increase change to make it mate ionic current I in ionic current compensation Ic _ieffect.Work as I _c=I _itime, underlayer voltage V _sub4512 become substantial constant, and IEDF width 4514 narrow becomes narrow from non-.

Once realize narrow IEDF, just ion energy can be adjusted to desired by going out as shown in Figure 46 or the numerical value defined.Herein, supply voltage (or in replacement scheme, the bus voltage V of switched-mode power supply _bus) size reduce (such as, the maximum negative amplitude of supply voltage 4606 pulse reduces).Therefore, Δ V ₁be reduced to Δ V ₂, peak-to-peak voltage too, from V _pP1be reduced to V _pP2like that.The underlayer voltage V of substantial constant _subthe size of 4608 correspondingly reduces, and therefore the size of ion energy is reduced to 4614 from 4615, keeps narrow IEDF width simultaneously.

No matter whether regulate ion energy, can after realizing narrow IEDF width, IEDF width be broadened, as shown in Figure 47.Herein, assuming that I _i=I _c(or in replacement scheme, equation 2 provides I _iand I _cbetween relation), adjustable I _c, the slope of the part between the pulse therefore changing modified periodic voltage function 4702.Because ionic current compensates Ic and ionic current I _iunequal, underlayer voltage basically constant move to non-constant.Further result is that IEDF width 4714 expands to non-narrow IEDF 4702 from narrow IEDF 4714.By I _ibe adjusted to more away from I _c, IEDF 4714 width is larger.

Figure 48 shows the pattern that can be used for the supply voltage realizing more than one ion energy level, and wherein, each ion energy level has narrow IEDF 4814 width.Each cycle alternation of the size of supply voltage 4806.This produces for the alternation Δ V in each cycle in modified periodic voltage function 4802 and peak-to-peak voltage.Underlayer voltage 4812 has the voltage of two substantial constant of alternation between the pulse of underlayer voltage then.This produces two different ions energy, and each ion energy has narrow IEDF 4814 width.

Figure 49 shows another pattern that may be used for the supply voltage realizing more than one ion energy level, and wherein, each ion energy level has narrow IEDF 4914 width.Herein, supply voltage 4906 is alternation between two different sizes, but also two cycles of alternation time before alternation.As see, mean ion energy is identical, as V _pS4906 each cycle alternation are the same.This only illustrates V _pShow each other pattern of 4906 is can for realizing an example of same ion energy.

Figure 50 shows the supply voltage V that may be used for creating the IEDF 5014 defined _pS5006 and ionic current compensate the combination of Ic 5004.Herein, alternating source voltage 5006 produces two different ions energy.In addition, be adjusted to away from ionic current I by ionic current is compensated 5004 _i, IEDF 5014 width of each ion energy of easily extensible.If ion energy is enough close, as it is in shown embodiment, then the IEDF 5014 of two ion energies is by overlap, produces a large IEDF5014.Other modification is also feasible, but be intended to illustrate can how by V for this example _pS5006 and I _cthe combination of the adjustment of 5004 is for the IEDF 5014 realizing defined ion energy He define.

Following reference diagram 17A and 17B, shows the block diagram describing other embodiments of the invention.As shown, the substrate support portion 1708 in these embodiments comprises electrostatic chuck 1782, and electrostatic chuck supply 1780 is for powering to electrostatic chuck 1782.In some variations, as shown in Figure 17 A, electrostatic chuck supply 1780 is arranged as powers directly to substrate support portion 1708, and in other modification, electrostatic chuck supply 1780 is arranged as powers in conjunction with switched-mode power supply.It should be noted that series connection chuck can be powered by independent current source or power to realize clean DC chuck function by use controller.(such as, not the having blocking capacitor) that be coupled at this DC connects in chuck function, can make the less desirable minimum interference with other RF source.

Figure 18 shows the block diagram that another embodiment of the present invention is shown, the plasma electrical source 1884 being wherein generally used for producing plasma density is also configured to substrate support portion 1808 and the electrostatic chuck supply 1880 on driving switch mode power 1806 side.In this embodiment, each in plasma electrical source 1884, electrostatic chuck supply 1880 and switched-mode power supply 1806 can be arranged in independently assembly, or two or more in power supply 1806,1880,1884 can be configured to be arranged in Same Physical assembly.Advantageously, the embodiment shown in Figure 18 makes top electrode 1886 (such as, shower nozzle) can be symmetrical and reduce the level of the damage caused due to a small amount of arc event to obtain electricity electrical ground.

With reference to Figure 19, show the block diagram that one more embodiment of the present invention is shown.As shown, switched-mode power supply 1906 in this embodiment is configured to power to substrate support portion and room 1904, to carry out biased to substrate and to light (and maintenance) both plasmas and without the need to extra plasma electrical source (such as, without the need to plasma electrical source 102,202,1202,1702,1884) such as, switched-mode power supply 1806 can provide biased duty ratio to carry out work to substrate support portion with maintain plasma to be enough to light simultaneously.

Following with reference to Figure 20, the block diagram that its control showing input parameter and control part exports, described control part can use in conjunction with referring to figs. 1 through the embodiment described by 19.Be intended to provide illustrating of simplification to the exemplary control inputs that can use in conjunction with embodiment as herein described and output to illustrating of control part, and also not intended to be is hardware diagram.In actual execution mode, shown control part can distribute among several discrete parts that can be realized by hardware, software, firmware and combination thereof.

With reference to above-described embodiment herein, the one or more function in the controller 1812 and 1912 that the controller shown in Figure 20 can provide the controller 112 described with reference to figure 1, the controller 212 described with reference to figure 2 and ion energy control assembly 220, the controller 812 that describes with reference to figure 8 and ion energy control part 820, the ionic current compensating unit 1260 described with reference to Figure 12, the current controller 1362 of reference Figure 13 description, the Icc control shown in Figure 16, Figure 17 A and 17B illustrate respectively controller 1712A and 1712B, Figure 18 and 19 illustrate respectively.

As shown, the parameter that can be used as the input of control section comprises with reference to Figure 13 and 14 dVo/dt and Δ V in greater detail.As mentioned above, dVo/dt may be used for coupled ion Energy distribution expansion input Δ E to provide control signal Icc, control signal Icc control with reference to Figure 12,13,14, the width of ion energy distribution expansion that describes of 15A-C and Figure 16.In addition, ion energy control inputs (Ei) may be used for producing ion energy control signal (such as in conjunction with optional feedback Δ V, Vbus shown in effect diagram 3), realize (definition) ion energy distribution expected in greater detail referring to figs. 1 to 11.And can be DC skew input in conjunction with another parameter of many e-chuck embodiments, it provides electrostatic force to be remained on chuck by wafer in order to effective thermal control.

Figure 21 shows the plasma process system 2100 according to the embodiment of present disclosure.System 2100 comprises the plasma processing chamber 2102 of the plasma 2104 of the top surface 2118 (and other plasma process) closed for etch substrate 2106.Plasma is produced (such as, original position or long-range or projection) by the plasma source 2112 of being powered by plasma electrical source 2122.The plasma sheath voltage V measured between plasma 2104 and the top surface 2118 of substrate 2106 _sheath _layermaking the ion from plasma 2104 accelerate to cross over plasma sheath 2115, causing the top surface 2118 of the ion collision substrate 2106 through accelerating and etch substrate 2106 (or not being subject to the part of photoresist protection in substrate 2106).Plasma 2104 is in plasma potential V relative to ground (such as, plasma processing chamber 2102 wall) ₃.Substrate 2106 has lower surface 2120, and lower surface 2120 is via the chuck current potential V between the top surface 2121 of electrostatic chuck 2111 and electrostatic chuck 2111 and substrate 2106 _chuckremain to support portion 2108 for electrostatically.Substrate 2106 is dielectrics, and therefore can have the first current potential V at top surface 2118 place ₁and the second current potential V can be had at lower surface 2120 place ₂.The top surface of electrostatic chuck 2121 contacts with the lower surface 2120 of substrate, and therefore these two surfaces 2120,2121 are in same current potential V ₂.First current potential V ₁, chuck current potential V _chuckwith the second current potential V ₂control via having the AC waveform that the DC produced by switched-mode power supply 2130 is biased or offsets, and be provided to electrostatic chuck 2111 via the first conductor 2124.Alternatively, provide AC waveform via the first conductor 2124, and provide DC waveform via optional second conductor 2125.Can carry out AC and the DC output of control switch mode power 2130 via controller 2132, controller 2132 is also configured to the various aspects of control switch mode power 2130.

Ion energy and ion energy distribution are the first current potential V ₁function.Switched-mode power supply 2130 provides the first current potential V expected through being trimmed to impact ₁aC waveform, the first current potential V of known described expectation ₁produce (or definition) ion energy and ion energy distribution expected.AC waveform can be RF and have the such as nonsinusoidal waveform shown in Fig. 5, Fig. 6, Figure 11, Figure 14, Figure 15 a, Figure 15 b and Figure 15 c.First current potential V ₁can with the voltage Δ V shown in Figure 14 be changing into ratio.First current potential V ₁also equal plasma voltage V ₃deduct plasma sheath voltage V _sheaths.But due to plasma sheath voltage V _sheaths(such as, 50V – 2000V) is compared, plasma voltage V ₃usually very little (such as, being less than 20V), therefore the first current potential V ₁with plasma sheath voltage V _sheathsapproximately equal and object for execution mode can be considered equal.Therefore, due to plasma sheath voltage V _sheathsindication ion energy, therefore the first current potential V ₁proportional with ion energy distribution.By keeping the first constant current potential V ₁, plasma sheath voltage V _sheathsconstant, and therefore substantially all ions accelerate via identical energy, and therefore realize narrow ion energy distribution.Plasma voltage V ₃obtained by the energy being imparted to plasma 2104 via plasma source 2112.

The first current potential V at top surface 2118 place of substrate 2106 ₁via the electrical capacitive charge from electrostatic chuck 2111 with formed from the combination by the electronics of sheaths 2115 and the charge accumulated of ion.From switched-mode power supply 2130 AC waveform through be trimmed to offset by the ion of sheaths 2115 and top surface 2118 place of electro transfer and substrate 2106 produce the impact of charge accumulated, to make the first current potential V ₁keep substantial constant.

Chuck power substrate 2106 being remained to electrostatic chuck 2111 is chuck current potential V _chuckfunction.Switched-mode power supply 2130 provides DC to be biased or DC skew, to make the second current potential V to AC waveform ₂be in and the first current potential V ₁different current potentials.This potential difference causes chucking voltage V _chuck.Chucking voltage V can be measured from the top surface 2221 of electrostatic chuck 2111 to the reference layer of substrate 2106 inside _chuck, wherein said reference layer comprises the arbitrary absolute altitude (elevation) except the lower surface 2120 (reference layer is in the accurate location alterable in substrate 2106) of substrate 2106 of substrate interior.Therefore, chuck is by the second current potential V ₂control and with the second current potential V ₂proportional.

In an embodiment, the second current potential V ₂equal the DC skew (in other words, have the AC waveform of DC skew, wherein DC skew is greater than the peak-to-peak voltage of AC waveform) of the switched-mode power supply 2130 revised by AC waveform.DC skew can be greater than AC waveform substantially, and the DC component exported to make switched-mode power supply 2130 arranges the second current potential V ₂and can ignore or ignore AC component.

Current potential in substrate 2106 is at first and second current potential V ₁, V ₂between change.Because the Coulomb attraction between substrate 2106 and electrostatic chuck 2111 exists, so chuck current potential V _chuckcan be plus or minus (such as, V ₁>V ₂or V ₁<V ₂), and not chuck current potential V _chuckpolarity why.

Switched-mode power supply 2130 can certainty ground and when without monitoring each voltage when transducer in conjunction with controller 2132.Especially, the parameter (such as, slope and step) based on AC waveform carrys out certainty ground monitoring ion energy (such as, average energy and ion energy distribution).Such as, plasma voltage V ₃, ion energy and ion energy distribution and the parameter of AC waveform that produced by switched-mode power supply 2130 proportional.Especially, Δ V (for example, see Figure 14) and the first current potential V of the trailing edge of AC waveform ₁proportional, and therefore proportional with ion energy.By keeping the first current potential V ₁constant, ion energy distribution can keep narrow.

Although the first current potential V directly can not be measured ₁and switched-mode power supply exports and the first voltage V ₁between correlation can based on the electric capacity of substrate 2106 and process parameter and changing, but can manage after time-out goes in weakness and empirically determine Δ V and the first current potential V ₁between proportionality constant.Such as, when the trailing edge Δ V of AC waveform is 50V and the proportionality constant empirically finding for given substrate and technique is 2, the first current potential V can be expected ₁for 100V.By equation 4, step voltage Δ V and the first current potential V is described ₁ratio between (and being therefore also ion energy eV).Therefore, can when plasma processing chamber 2102 inside to be without any transducer, the knowledge based on the AC waveform of switched-mode power supply determines the first current potential V ₁and ion energy and ion energy distribution.In addition, whether whether switched-mode power supply 2130 can be monitored chuck in conjunction with controller 2132 and when occur and occur (such as, via chuck current potential V _chucksubstrate 2106 is remained to electrostatic chuck 2111).

By eliminating or reducing chuck current potential V _chuckperform chuck (dechucking).This is by by the second current potential V ₂be set to equal the first current potential V ₁come.In other words, DC skew and AC waveform can be regulated to cause chucking voltage V _chuckclose to 0V.Compared with going chuck method with routine, system 2100 realizes removing chuck faster and therefore larger flux because DC can be regulated to offset and AC waveform so that chuck is removed in realization.Equally, when DC and AC power supplies are in switched-mode power supply 2130, its circuit is more unified, more closely together, can control (comparing as arranged with the canonical parallel of AC power supplies with DC), and change output quickly via single controller 2132.The speed of chuck of going realized by embodiment disclosed herein also after plasma 2104 extinguishes or at least realizes removing chuck after closing the electric power from plasma source 2112.

Plasma source 2112 can take various ways.Such as, in an embodiment, plasma source 2112 comprises electrode in plasma processing chamber 2102 inside, and it sets up and lights and the RF field of maintain plasma 2104 in room 2102.In another embodiment, plasma source 2112 comprises the plasma source of long-range projection, it remotely produces ionization electromagnetic field, is projected by ionization electromagnetic field or extend in process chamber 2102, and uses ionization electromagnetic field to light in plasma processing chamber and maintain plasma 2104.But, the plasma source of long-range projection also comprises ionization electromagnetic field and arrives the field translator unit that passes through in the way of plasma processing chamber 2102 (such as, contact tube), during this period, ionization electromagnetic field decay, with make the field intensity in plasma processing chamber 2102 be only field intensity when first described field produces in long-range projection plasma source 1/10th, one of percentage, one thousandth or even more fraction.Plasma source 2112 not drawn on scale.

Switched-mode power supply 2130 can float and therefore can be offset to be biased with any DC by the DC power supply (not shown) be connected in series between ground and switched-mode power supply 2130.Switched-mode power supply 2130 via AC and the DC power supply (for example, see Figure 22, Figure 23, Figure 26) of switched-mode power supply 2130 inside or can provide the AC waveform with DC skew via the AC power supplies of switched-mode power supply 2130 inside and the DC power supply (for example, see Figure 24, Figure 27) of switched-mode power supply 2130 outside.In an embodiment, switched-mode power supply 2130 can ground connection and be coupled in series to the floating DC power supply of series coupled between switched-mode power supply 2130 and electrostatic chuck 2111.

When switched-mode power supply 2130 comprises AC and DC power supply, AC and DC of controller 2132 controllable switch mode power exports.When switched-mode power supply 2130 is connected with DC power sources in series, controller 2132 can only control switch mode power 2130 AC export.In alternative embodiments, both the controller 2130 DC power supply that can control to be coupled to switched-mode power supply 2130 and switched-mode power supply 2130.Those skilled in the art will recognize that, although show single controller 2132, also can implement other controller to control to be provided to AC waveform and the DC skew of electrostatic chuck 2111.

Electrostatic chuck 2111 can be dielectric (such as, pottery) and therefore substantially stop that DC voltage passes through, or it can be semiconductive material, such as through the pottery of doping.In either case, electrostatic chuck 2111 can have the second voltage V on the top surface 2121 of electrostatic chuck 2111 ₂, voltage capacitor is coupled to the top surface 2118 of substrate 2106 (usual dielectric) to form the first voltage V by electrostatic chuck 2111 ₁.

Plasma 2104 shape and size need not be drawn in proportion.Such as, by the edge of a certain plasma density plasma by definition 2104, in the case, shown plasma 2104 is not drawn with considered any particular plasma volume density.Similarly, at least some plasma density fills whole plasma processing chamber 2102, and no matter shown plasma 2104 shape how.Shown plasma 2104 shape is mainly intended to sheaths 2115 is shown, sheaths 2115 has substantially little than plasma 2104 plasma density.

Figure 22 shows another embodiment of plasma process system 2200.In the embodiment illustrated, switched-mode power supply 2230 comprises the DC power supply 2234 and AC power supplies 2236 that are connected in series.The AC waveform that the DC skew that controller 2232 is configured to be biased or control to have both skew switched-mode power supply 2230 by control AC power supplies 2236 waveform and DC power supply 2234 exports.This embodiment also comprises electrostatic chuck 2211, and it has and is embedded in gate electrode in chuck 2211 or mesh electrode 2210.Switched-mode power supply 2230 provides AC and DC to be biased both to gate electrode 2210.DC is biased sets up the 3rd current potential V together with AC component (it is substantially less than DC and is biased and can be therefore left in the basket) on gate electrode 2210 ₄.As the 3rd current potential V ₄when being different from the current potential at the reference layer place of any position in substrate 2206 (except the lower surface 2220 of substrate 2206), set up chuck current potential V _chuckwith Coulombic chuck power, substrate 2206 is remained to electrostatic chuck 2211 by it.Described reference layer is the imaginary plane being parallel to gate electrode 2210.AC waveform is capacitively coupled through a part for electrostatic chuck 2211 from gate electrode 2210, and by substrate 2206 to control the first current potential V on the top surface 2218 of substrate 2206 ₁.Due to plasma potential V ₃relative to plasma sheath voltage V _sheathscan ignore, therefore the first current potential V ₁with plasma sheath voltage V _sheathsapproximately equal, and be considered as equal for actual object.Therefore, the first current potential V ₁equal the current potential for accelerating the ion by sheaths 2215.

In an embodiment, can adulterate to electrostatic chuck 2211, can ignore to make any potential difference of the body by chuck 2211 to have enough conductivity, and therefore gate electrode or mesh electrode 2210 can be in and the second current potential V substantially ₂identical voltage.

Gate electrode 2210 can be embedded in electrostatic chuck 2211, be parallel to any conductive plane device of substrate 2206, and is configured to undertaken biased by switched-mode power supply 2230 and set up chuck current potential V _chuck.Although gate electrode 2210 is depicted as in the low portion being embedded in electrostatic chuck 2211, gate electrode 2210 can from substrate 2206 more close to or locate further.Gate electrode 2210 also need not have gate pattern.In an embodiment, gate electrode 2210 can be solid electrode or have the non-solid structure being with non-grid shape (such as, checkerboard pattern).In an embodiment, electrostatic chuck 2211 is pottery or other dielectric, and the 3rd current potential V therefore on gate electrode 2210 ₄be not equal to the first current potential V on the top surface 2221 of electrostatic chuck 2211 ₁.In another embodiment, electrostatic chuck 2211 is the potteries through doping conducted electricity a little, and the 3rd current potential V therefore on gate electrode 2210 ₄the second current potential V on the top surface 2221 of electrostatic chuck 2211 can be equaled ₂.

It can be that the AC that non-sine exports exports that switched-mode power supply 2230 produces.Switched-mode power supply 2230 can the DC of operating series and AC power supplies 2234,2236, because DC power supply 2234 is AC conduction type (AC-conductive), and AC power supplies 2236 is DC conduction type (DC-conductive).Not for the exemplary AC power supplies of DC conduction type is can some linear amplifier vitiable when providing and having DC voltage or electric current.Use the quantity decreasing the parts of use in switched-mode power supply 2230 with the power supply of DC conduction type of AC conduction type.Such as, if DC power supply 2234 is AC barrier types, then AC bypass type or DC barrier type parts (such as, capacitor) can be arranged in parallel with DC power supply 2234.If AC power supplies 2236 is DC barrier types, then DC bypass type or AC barrier type parts (such as, inductor) can be arranged in parallel with AC power supplies 2236.

In this embodiment, AC power supplies 2238 is configured to controllably apply voltage bias to electrostatic chuck 2211 usually, thus the expectation of the ion of the top surface 2218 of realization bombardment substrate 2206 (or definition) ion energy distribution.More particularly, AC power supplies 2236 is configured to (or definition) ion energy distribution by applying one or more specific waveforms to realize to gate electrode 2210 to expect with certain power level.And more particularly, AC power supplies 2236 applies certain power level to realize specific ion energy, and the one or more voltage waveforms defined by the Wave data be stored in wave memorizer (not shown) are used to apply certain power level.Therefore, one or more specific ion bombarding energy can be selected to perform controlled etching (or other plasma assisted process) to substrate 2206.In one embodiment, AC power supplies 2236 can utilize switching mode to configure (for example, see Figure 25-27).Switched-mode power supply 2230 (and more particularly AC power supplies 2236) can produce the AC waveform as described in each embodiment of present disclosure.

Those skilled in the art will recognize that, gate electrode 2210 may dispensable and other embodiment can when without gate electrode 2210 implement.Those of skill in the art also will appreciate that, gate electrode 2210 is only can be used for setting up chuck current potential V _chuckan example of many devices.

Figure 23 shows another embodiment of plasma process system 2300.Shown embodiment comprises the switched-mode power supply 2330 for providing AC waveform and DC to be biased to electrostatic chuck 2311.Switched-mode power supply 2330 comprises DC power supply 2334 and AC power supplies 2336, and these two power supplys all can ground connection.AC power supplies 2336 produces the AC waveform provided to the first grid electrode be embedded in electrostatic chuck 2311 or mesh electrode 2310 via the first conductor 2324.AC power supplies 2336 sets up current potential V on first grid electrode or mesh electrode 2310 ₄.The DC that DC power supply 2334 produces to be provided to the second gate electrode be embedded in electrostatic chuck 2311 or mesh electrode 2312 via the second conductor 2325 is biased.DC power supply 2334 sets up current potential V on second gate electrode or mesh electrode 2312 ₅.Current potential V ₄and V ₅can control independently via AC and DC power supply 2336,2334 respectively.But the first and second gate electrodes or mesh electrode 2310,2312 capacitively can also be coupled and/or can there is DC coupling via the part in electrostatic chuck 2311 between gate electrode or mesh electrode 2310,2312.If there is AC or DC coupling, then can Coupling Potential V ₄and V ₅.Those skilled in the art will recognize that, the first and second gate electrodes 2310,2312 can be arranged in the various positions of electrostatic chuck 2311, comprise and first grid electrode 2310 are set to second grid electrode 2312 closer in substrate 2306.

Figure 24 shows another embodiment of plasma process system 2400.In this embodiment, switched-mode power supply 2430 provides AC waveform to electrostatic chuck 2411, and wherein switched-mode power supply 2430 exports the DC provided by DC power supply 2434 and is biased and offsets.The AC waveform of switched-mode power supply 2430 has the waveform selected by controller 2435, so that by from having the ion of plasma 2404 of narrow ion energy distribution to bombard substrate 2406.AC waveform can be nonsinusoidal waveform (such as, square wave or pulse) and can produce via the AC power supplies 2436 of switched-mode power supply 2430.Chuck controls via the DC skew from DC power supply 2434, and DC power supply 2434 is controlled by controller 2433.DC power supply 2434 can between ground and switched-mode power supply 2430 series coupled.Switched-mode power supply 2430 is floating, and to make, its DC is biased can be arranged by DC power supply 2434.

Those skilled in the art will recognize that, although shown embodiment shows two independent controls 2433,2435, these controllers can be combined in individual feature unit, equipment or system (such as, alternative controls 2432).In addition, can Coupling Control Unit 2433 and 2435, thus communicate with one another and shared processing resources.

Figure 25 shows the further embodiment of plasma process system 2500.Shown embodiment comprises switched-mode power supply 2530, and switched-mode power supply 2530 produces the AC waveform can with the DC skew provided by DC power supply (not shown).Described switched-mode power supply can control via alternative controls 2535, and alternative controls 2535 comprises voltage and current controller 2537,2539.Switched-mode power supply 2530 can comprise the voltage controllable voltage source 2538 exported and the controllable current source 2540 with the electric current output controlled by current controller 2539 that have and controlled by voltage controller 2537.Can control voltage and current source 2538,2540 can in being arranged in parallel.The ionic current that controllable current source 2540 is configured between plasma 2504 and substrate 2506 compensates.

Voltage and current controller 2537,2539 can be coupled and communicate with one another.The switch that voltage controller 2537 can also control controllable voltage source 2538 exports 2539.Switch exports 2539 can comprise two switches in parallel as shown, maybe can comprise any circuit output of controllable voltage source 2538 being converted to desired AC waveform (such as, nonsinusoidal waveform).Via described two switches, can export with the controlled current flow in controllable current source 2540 from the controlled voltage of controllable voltage source 2538 or AC waveform and combine, to produce the AC wave form output of switched-mode power supply 2530.

Controllable voltage source 2538 is depicted as has given polarity, but those skilled in the art will recognize that, opposite polarity is equivalent to shown polarity.Alternatively, can control voltage and current source 2538,2540 and export together with switch the part that 2539 can be AC power supplies 2536, and the DC power supply (not shown) that AC power supplies 2536 can be inner or outside with being positioned at switched-mode power supply 2530 is arranged in series.

Figure 26 shows the another embodiment of plasma process system 2600.In the embodiment illustrated, switched-mode power supply 2630 provides the AC waveform with DC skew to electrostatic chuck 2611.The parallel combination that the AC component of described waveform exports 2639 controllable voltage source 2638 be connected to each other and controllable current source 2640 through switch produces.DC skew is produced by the DC power supply 2634 of series coupled between ground and controllable voltage source 2638.In an embodiment, DC power supply 2634 can be floating and ungrounded.Similarly, switched-mode power supply 2630 can be floating or ground connection.

System 2600 can comprise one or more controllers of the output for control switch mode power 2630.First controller 2632 such as can carry out the output of control switch mode power 2630 via second controller 2633 and the 3rd controller 2635.Second controller 2633 can control the DC skew of the switched-mode power supply 2630 as produced by DC power supply 2634.3rd controller 2635 can carry out the AC waveform of control switch mode power 2630 by control controllable voltage source 2638 and controllable current source 2640.In an embodiment, the voltage that voltage controller 2637 controls controllable voltage source 2638 exports, and current controller 2639 controls the electric current in controllable current source 2640.Voltage and current controller 2637,2639 can communicate with one another and can be the part of the 3rd controller 2635.

Those skilled in the art will recognize that, describing controller is not restrictive relative to the above embodiment of the various configurations of power supply 2634,2638,2640, and can implement other configuration various, and does not depart from present disclosure.Such as, the switch that the 3rd controller 2635 or voltage controller 2637 can control between controllable voltage source 2638 and controllable current source 2640 exports 2639.As another example, second and the 3rd controller 2633,2635 can communicate with one another (although so not illustrating).Should also be understood that the polarity that can control voltage and current source 2638,2640 is only exemplary and is not intended to be restrictive.

Console switch output 2639 can be carried out to make AC waveform shaping by replacing switching two paralleling switches.Switch exports the switch that 2639 can comprise any kind, includes but not limited to MOSFET and BJT.In a modification, DC power supply 2634 can be arranged on controllable current source 2640 and and electrostatic chuck 2611 between (in other words, DC power supply 2634 can be floating), and switched-mode power supply 2630 can ground connection.

Figure 27 shows another embodiment of plasma process system 2700.In this modification, switched-mode power supply 2734 ground connection again, instead of be incorporated in switched-mode power supply 2730, herein, DC power supply 2734 is individual components and provides DC to offset to whole switched-mode power supply 2730 (but not the parts only in switched-mode power supply 2730).

Figure 28 shows the method 2800 according to the embodiment of present disclosure.Method 2800 comprises the operation 2802 be placed on by substrate in plasma chamber.Method 2800 is also included in plasma chamber the operation 2804 forming plasma.This plasma original position can be formed or formed via long-range projection source.Method 2800 also comprises Switching Power Supply operation 2806.Switching Power Supply operation 2806 relate to controllably switch to the electric power of substrate, thus to substrate applying periodic voltage function.Described periodic voltage function can be regarded as impulse waveform (such as, square wave) or AC waveform, and comprises the DC produced by the DC power supply of connecting with switched-mode power supply and offset.In an embodiment, DC power supply can be incorporated in switched-mode power supply, and therefore connect with the AC power supplies of switched-mode power supply.DC skew produces potential difference between the reference layer in the top surface and substrate of electrostatic chuck, and this potential difference is called as chuck current potential.Substrate is remained to electrostatic chuck by the chuck current potential between electrostatic chuck and substrate, therefore prevents substrate from moving during processing.Method 2800 also comprises modulation operations 2808, wherein modulates periodic voltage function during multiple cycle.(or definition) ion energy distribution of the expectation of described modulated response in the surface of substrate, thus realize expecting on time averaging basis (or definition) ion energy distribution.

Figure 29 shows another method 2900 of the embodiment according to present disclosure.Method 2900 comprises the operation 2902 be placed on by substrate in plasma chamber.Method 2900 is also included in plasma chamber the operation 2904 forming plasma.Described plasma original position can be formed or formed via long-range projection source.Method 2900 also comprises the operation 2906 receiving at least one ion energy distribution and arrange.In reception operation 2906, the described of reception arranges one or more ion energies that can indicate the surface of substrate.Method 2900 also comprises Switching Power Supply operation 2908, and wherein controllably switch, to the electric power of substrate, thus realizes the following: the expectation of (1) ion energy on time averaging basis (or define) distribution; And the chuck current potential of (2) expectation on time averaging basis.Power supply can have AC waveform and DC skew.

In a word, in other side, the invention provides a kind of method and apparatus for using switched-mode power supply optionally to produce (or definition) ion energy of expectation.It will be readily appreciated by those skilled in the art that and can make many modification in the present invention and substitute, its purposes and configuration thereof realize the identical result substantially realized with embodiment as herein described.Therefore, the present invention is not limited to the intention of disclosed example form.Many modification, amendment and alternative structure all fall in disclosed scope and spirit of the present invention.

Claims

1., for setting up a method for one or more plasma sheath voltage, comprising:

Substrate support to plasma chamber provides modified periodic voltage function, wherein, described substrate support is coupled to the substrate being configured in and carrying out in described plasma processing, and wherein, described modified periodic voltage function comprises the periodic voltage function being compensated Ic amendment by ionic current

Wherein, described modified periodic voltage function comprises the part between pulse and described pulse,

Wherein, described pulse is the function of described periodic voltage function, and

Wherein, the slope of the described part between described pulse is the function that described ionic current compensates Ic;

Access at least represents the effective capacitance value C of the electric capacity of described substrate support ₁; And

Identify that the described ionic current of the ion energy distribution function of the definition of the ion by producing the surface arriving described substrate compensates the numerical value of Ic, wherein, described identification is described effective capacitance C ₁and the slope V of described part between described pulse ₀the function of/dt.

2. method according to claim 1, wherein, the ion energy distribution of described definition is narrow ion energy distribution.

3. method according to claim 2, wherein, corresponding with the constant voltage at described substrate surface place during the ion energy distribution of the described definition described part between described pulse.

4. method according to claim 1, wherein, the numerical value that described ionic current compensates Ic meets following function f:

f (I_{C}) = \frac{d V_{0}}{dt} - \frac{I_{C}}{C_{1}} = 0 .

5. method according to claim 4, also comprises:

Described ionic current is compensated Ic and is set to the first numerical value;

Determine the symbol of described function f; And

If the described symbol of described function f is just, then increases described ionic current and compensate Ic, and if the described symbol of described function f is negative, then reduces described ionic current and compensate Ic.

6. method according to claim 1, wherein, described identification is included in the voltage of two or more moment to the described part between described pulse and samples.

7. method according to claim 6, wherein, the voltage that described identification comprises according to sampling in two or more moment described calculates described slope dV ₀/ dt.

8. method according to claim 7, wherein, described identification comprises slope dV described in two or more computation of Period for described modified periodic voltage function ₀/ dt, wherein, the different numerical value that each cycle in two or more cycles described and described ionic current compensate Ic are associated.

9. method according to claim 6, wherein, sample, and the voltage of at least sampling according to these calculates described slope dV during described identification is included in the period 1 during second round to the voltage of the described part between described pulse ₀/ dt.

10. method according to claim 1, wherein, described ionic current compensates the ionic current I of Ic and the plasma sheath through described plasma _ilinear correlation.

11. methods according to claim 10, wherein, described ionic current compensates Ic according to following equation and described ionic current I _ilinear correlation:

Wherein, C ₁the effective capacitance seen by bias supply of described plasma chamber, and C _spuiousit is the accumulation stray capacitance seen by described bias supply of described plasma chamber.

12. methods according to claim 11, wherein, described effective capacitance C ₁change in time.

13. methods according to claim 11, wherein, described ionic current compensates Ic to be changed in time.

14. methods according to claim 1, also comprise and provide described modified periodic voltage function to described substrate support, arrive the described surface of described substrate to make ion with the first ion energy.

15. methods according to claim 14, wherein, described modified periodic voltage function has first voltage step corresponding with described first ion energy.

16. methods according to claim 15, the second value also comprised by described ionic current compensation Ic provides described modified periodic voltage function to described substrate support, thus widens described ion energy distribution function.

17. methods according to claim 15, wherein, provide described first voltage step and the second voltage step in the adjacent periods of described modified periodic voltage function.

18. methods according to claim 14, wherein, described in provide, on the density of described plasma, there is negligible impact.

19. 1 kinds are carried out for plasma the method that the biased thus surface of substrate in plasma processing chamber realizes the ion energy of definition, and described method comprises:

The modified periodic voltage function comprising the periodic voltage function being compensated amendment by ionic current is applied to substrate support;

At least one cycle of described modified periodic voltage function is sampled, to produce voltage data point;

The numerical value of first ion energy at described substrate surface place is estimated according to described voltage data point; And

Regulate described modified periodic voltage function, until described first ion energy equals the ion energy of described definition.

20. methods according to claim 19, also comprise and sampling at least one cycle of described modified periodic voltage function, and calculate the described numerical value of described first ion energy after each voltage of described adjustment increases.

21. methods according to claim 19, wherein, described estimation is the function of the ionic current as input.

22. methods according to claim 21, wherein, described ionic current is the function that described ionic current compensates.

23. methods according to claim 22, wherein, use following equation in the described estimation of the numerical value to described first ion energy:

Wherein, Δ V is described voltage step, C ₁the effective capacitance seen by bias supply of described room, and C _sheathsbe the sheath layer capacitance of described plasma sheath, it depends on described ionic current.

24. methods according to claim 23, wherein, described adjustment comprises the described step voltage Δ V regulating described modified periodic voltage function, until described first ion energy equals the ion energy of described definition.

25. methods according to claim 19, also comprise the first numerical value compensated by described ionic current and become second value, thus widen the width of the distribution of described ion energy.

26. methods according to claim 19, wherein, described applying and the plasma density of described adjustment on described plasma have negligible impact.

27. methods according to claim 19, wherein, described adjustment comprises adjustment bias supply voltage, until described first ion energy equals the ion energy of described definition.

28. 1 kinds in order to realize the method for ion energy distribution function width, described method comprises:

Substrate support to plasma processing chamber provides modified periodic voltage function;

In the first moment and in the second moment from described nonsinusoidal waveform sampling at least two voltages;

The slope of described at least two voltages is calculated as dV/dt;

Described slope and known reference slope are compared, so that corresponding with ion energy distribution function width; And

Regulate described modified periodic voltage function, to make described slope close to described with reference to slope.

29. methods according to claim 28, wherein, during described first moment occurs in the period 1 of described modified periodic voltage function, and during described second moment occurs in the second round of described modified periodic voltage function.

30. methods according to claim 28, wherein, during described first moment and described second moment occur in the same period of described modified periodic voltage function.

31. methods according to claim 28, wherein, perform described sampling with the sample rate of at least 400kHz.

32. 1 kinds of systems, comprising:

Plasma processing chamber, described plasma processing chamber is configured to contain plasma;

Substrate support, described substrate support to be placed in described plasma processing chamber and to be positioned to support substrates during plasma treatment;

Power supply, described power supply provides periodic voltage function to described substrate support, and described periodic voltage function has the part between pulse and described pulse;

Ionic current compensating unit, described ionic current compensating unit revises the slope of the described part between described pulse, to form the modified periodic voltage function provided to described substrate support; And

Controller, described controller communicates with described ionic current compensating unit with described switched-mode power supply, and be configured to the numerical value identifying that described ionic current compensates, if provide described ionic current to compensate to described substrate support, the ion energy distribution function of the definition of the ion on the surface arriving described substrate will be produced.

33. devices according to claim 32, wherein, the amplitude that described controller regulates described ionic current to compensate, until the ion energy distribution function realizing the described definition of the ion on the described surface arriving described substrate.

34. devices according to claim 32, wherein, described controller is also configured to the amplitude of the described pulse identifying described periodic voltage function, if provide the described pulse of described periodic voltage function to described substrate support, the ion energy of the definition of the ion on the described surface arriving described substrate will be produced.

35. devices according to claim 34, wherein, described controller regulates the amplitude of the described pulse of described periodic voltage function, until realize the ion energy of the described definition of the ion on the described surface arriving described substrate.

The tangible computer readable storage medium storing program for executing of 36. 1 kinds of non-transitory, its coding has processor instructions, to perform the method for monitoring the ionic current being configured to the plasma processing substrate, described method comprises:

Under considering the ionic current compensation situation with the first numerical value, modified periodic voltage function is sampled;

Under considering the described ionic current compensation situation with second value, described modified periodic voltage function is sampled;

The slope of the described modified periodic voltage function of the function as the time is determined based on described first sampling and described second sampling; And

Calculate the third value of described ionic current compensation based on described slope, at described third value place, at least one cycle memory at described modified periodic voltage function exists by the constant voltage on described substrate.

The tangible computer readable storage medium storing program for executing of 37. non-transitory according to claim 36, also comprises the plasma arc voltage at the plasma sheath two ends calculating described plasma.