CN100382249C - A method and apparatus for process control in time division multiplexed TDM etch processes - Google Patents
A method and apparatus for process control in time division multiplexed TDM etch processes Download PDFInfo
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- CN100382249C CN100382249C CNB2004800092633A CN200480009263A CN100382249C CN 100382249 C CN100382249 C CN 100382249C CN B2004800092633 A CNB2004800092633 A CN B2004800092633A CN 200480009263 A CN200480009263 A CN 200480009263A CN 100382249 C CN100382249 C CN 100382249C
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Abstract
The present invention provides a method for controlling pressure in a vacuum chamber during a time division multiplexed process. A throttle valve is pre-positioned and held for a predetermined period of time. A process gas is introduced into the vacuum chamber during the associated plasma step (deposition or etching) of the silicon wafer. At the end of the predetermined period of time, the process gas continues to flow with the throttle valve being released from the set position. At this point, the throttle valve is regulated through a proportional derivative and integral control for a period that lasts the remaining time of the associated plasma step.
Description
The cross reference of related application
The application requires to enjoy the U.S. Provisional Patent Application sequence number of owning together 60/460 that the name that proposed on April 7th, 2003 is called " course control method for use in the Time Division Multiplexing etch process and equipment ", 932 priority, and relevant with it, described temporary patent application is incorporated herein by reference at this.
Technical field
The present invention relates generally to the field of semiconductor wafer processing.More specifically, the present invention relates to be used for the method and apparatus of control chamber pressure during time division multiplexing etching and deposition process.
Background technology
In the manufacturing of micro electronmechanical (MEMS) device, be extensive use of the making of high aspect ratio silicon device.Such device usually has from tens degree of depth to the change of hundreds of micron.In order to ensure manufacturability, etching process must carry out with high etching speed, keeping rational output, and other performance requirements such as smooth etching section.
The plasma etch processes of traditional one step can not satisfy these needs simultaneously, and has developed time division multiplexed etch processes.The Time Division Multiplexing method that is used for etching silicon is by people (U.S. 5,501,893) explanations such as people (U.S. 4,795,529) such as people such as Suzuki (U.S. 4,579,623), Kawasaki and Laermer.The TDM etch process typically uses alternately etching and deposition step.For example, during etching silicon (Si) substrate, sulphur hexafluoride (SF
6) as etching gas, and octafluoroization four carbon (C
4F
8) as deposition gases.In etching step, SF
6Help spontaneous isotropic silicon (Si) etching; In deposition step, C
4F
8Help making the polymer inactivation of protectiveness on the sidewall and bottom of etch structures.In etching step subsequently, in case be subjected to the high energy directional ion bombardment, the polymer film that covers from the etch structures bottom of deposition step formerly just will be removed, and be used for further etched silicon face with exposure.Polymer film on the sidewall will keep, to suppress the etching of side.The TDM process is cycle alternation between etching and deposition process, so that high-aspect-ratio structure can be limited in the silicon chip of sheltering with high etching speed.
In each process steps, with the flow velocity of appointment in the process approach by air inlet with gas (SF for example
6And C
4F
8) the introducing reative cell.Typically (for example inductively coupled plasma (ICP), electron cyclotron resonace (ECR) or the like) carries out the TDM etch process in high density plasma reactors.
The TDM process approach is made up of a series of process circulations and step.Each circulation is made up of two above process steps, described process steps control procedure variable (for example gas flow rate, chamber pressure, RF power, process steps number of times, room temperature, chip temperature or the like).Step within the circulation in carrying out total process approach next procedure or circulation before be repeated several times.Known when circulation repeats to the process step parameters change to improve etching performance, this is called as process variant (process morphing) (seeing people's such as Teixeira the U.S. 6,417,013) technically.
Pressure control is the important component part of etching and deposition process.For manufacture process repeatably, the flow velocity and the pressure of the process gas that exists in must careful control room are with deposition and the etching characteristic that expection is provided.
The TDM plasma reactor evacuation system typically comprises turbine pump, and it is isolated by choke valve and reative cell.Pressure controller uses and controls choke valve from manometric chamber pressure data.Controller opens or close choke valve to increase or to reduce from the vacuum degree of turbine pump to the reative cell supply.In this way, controller is kept the expecting pressure in the reative cell.During the TDM process, chamber pressure set point and gas flow rate be cycle alternation within the process circulation.Air-flow can be the mixed of single component or multiple composition.Pressure controller must be regulated throttle valve position to compensate flowing and pressure condition of these changes.Ideally, pressure controller regulate throttle valve position do not have to reach pressure set-point immediately pressure set point overshoot or under dash.
Current available choke valve and controller typically move under pressure control mode or position control mode.Under pressure control mode, controller monitors the pressure in the reative cell, and keeps set point pressure (that is closed loop pressure control) by the position of regulating choke valve.Under position control mode, controller navigates to set point with choke valve and monitoring room pressure (that is open loop pressure control) not.
Some groups have been used for the device of the process control of plasma chamber in consideration.People such as Kessel (U.S. 4,253,480) have described the pressure regulator that uses adjustable electromagnetically operated valve to come controlled pressure.Kessel has instructed the basic mechanism of the operation of the many choke valves that use in the indication vacuum chamber.Actual pressure in the container is measured and convert the signal of telecommunication to.Comparator generates calibrating signal, poor between its expression actual pressure and the command pressure.Adjuster uses calibrating signal to instruct the valve of following manner, and described mode is: valve part is adjustable between the centre position within the scope between the opening and closing position of valve.In fact, follow the choke valve that uses in such operate TDM process tool.Yet, as explanation early, can not controlled pressure be realistic problem, and can not solve by the technology of Kessel in the transition period of the TDM process steps that often replaces.
People such as the Kaveh (U.S. 5,758,680) and the people (U.S. 6 such as McMillin, 142,163) use of ballast port (ballast port) has been described, described ballast port is used for gas is added the pressure oscillation of evacuation system with the compensatory reaction chamber, so that the throttle valve movement between the various process step is minimized.They have further disclosed a kind of method, are used for the time of the gas stabilization of vacuum chamber with minimizing.At first that choke valve is pre-aligned to desired location.Use predetermined estimation curve estimated expected position.For the specific period, enable proportion differential (PD) and control throttle valve movement then.Enable proportion integration differentiation (PID) control then and come regulate throttle valve movement.The example of instructing in the disclosure shows that the time interval that is used for pressure stability was reduced to 3-5 second at least from～20 seconds.Although Kaveh and McMillin have thought deeply when the variation of process step from gas flow rate and a pressure when the next one changes, do not instruct the use in the cycle alternation TDM process.In addition, many TDM processes are used and are only continued several seconds or shorter alternation procedure step, and this makes that the pressure control of using the technology that discloses is unrealistic.
People such as Brown (U.S. 6,119,710) have described and have entered the use of reative cell with the scalable air-flow of the variation of the pressure in the compensated chamber.Yet in many TDM processes, it is undesirable changing the process gas flow velocity during process steps.
People such as Beyer (U.S. 5,944,049) have described by the internal pressure of the compression stage of the exhaust pressure of the exhaust side of control vacuum pump or first vacuum pump and have come conditioning chamber pressure.The adjusting of vacuum pump speed is injected inert gas the adjusting of exhaust side of vacuum pump or the adjusting of compression stage and is used to control chamber pressure.How Beyer not instruction uses this technology in the TDM process.
Puech (U.S. Patent application 20020168467) has described the method for controlled pressure is come near the zone the torpescence control gaseous injection pump drainage mouth by with additional flow velocity.Regulate the flow velocity of controlled inactive gas, so that keep the total air-flow that enters vacuum chamber with fixing basically speed.Although Puech has instructed the pressure control in the TDM process of using the process steps that is equivalent to a second, this method is not taught in the use of active adjustment choke valve in the pressure control.
The pressure controlled current method that is used for the TDM process, that is pressure control and Position Control, be have circumscribed.A problem of the pressure control mode in the TDM process is, in fact, typically exists compromise between reaching the rapid pressure response time set point being departed to minimize.Fast response time is that cost is possible with one section pressure set point overshoot.Optimize available pressure control mode algorithm so that set point overshoot minimizes causes the slow-response time.Along with the TDM step duration reduces, the time that set point spent that reaches the method appointment as possible becomes important a part of processing time.
The problem of the current method of the position control mode in the TDM process is unacceptable long pressure response time.Overshoot minimizes although mode position makes process, and the process time that the slower response time causes the big section of chamber pressure cost is with near the set-point value that requires (that is, outside the set point that meets the method appointment).
Another problem of position control mode method is that it is an open loop pressure control algolithm.Therefore, there is not the correction of any disturbance at air-flow or pumping efficiency.These disturbances tend to cause pressure process and so and next process performance changes in time.
Therefore, have the needs for pressure control device, described pressure control device is used for the TDM process, and being preferably used for using the duration is those processes of following process steps in several seconds.
The benefit that prior art does not provide the present invention to bring.
Therefore, a target of the present invention provides a kind of improvement, and it has overcome the deficiency of prior-art devices, and is the remarkable contribution to the semiconductor processing techniques progress.
Another target of the present invention provides a kind of method, be used for the anisotropically device of etch substrate, the method includes the steps of: make substrate stand the alternate cycles process within plasma chamber, described alternate cycles process has etching step and deposition step; During the deposition step of described alternate cycles process, in described plasma chamber, introduce first process gas, be used for film is deposited to substrate; During the etching step of described alternate cycles process, in described plasma chamber, introduce second process gas, be used for etch substrate; During at least one step of described alternate cycles process, reach predetermined a period of time by choke valve being arranged on the preposition set point, regulate the pressure of described plasma chamber; For the deposition step of described alternate cycles process and the etching step of described alternate cycles process, combustion plasm(a) reaches a period of time of method appointment; After described expiration of predetermined a period of time, enable the closed loop pressure control algolithm; And, in described plasma chamber, pressure is controlled at the pressure set-point of method appointment by to carrying out closed loop pressure control the remaining time of step.
Another target of the present invention provides the pressure controlled method in a kind of time division multiplexed process, it comprises following steps: reach predetermined a period of time by choke valve being arranged on the preposition set point, regulate the pressure process in the vacuum chamber at least one step of time division multiplexed process; In described vacuum chamber, introduce at least a process gas; After described expiration of predetermined a period of time, enable the closed loop pressure control algolithm; And, pressure is controlled at the pressure set-point of method appointment by to carrying out closed loop pressure control the remaining time of the described step of time division multiplexed process.
Also target of the present invention provides a kind of method, is used for controlling the pressure of vacuum chamber, and the method includes the steps of: reach predetermined a period of time by choke valve being arranged on the preposition set point, regulate the pressure process in the vacuum chamber; In described vacuum chamber, introduce gas; After described expiration of predetermined a period of time, enable the closed loop pressure control algolithm; And be controlled at the pressure set-point that in the described vacuum chamber pressure is controlled at the method appointment by closed loop pressure.
Related objectives more of the present invention have been summarized in the front.It only is some exemplary relatively notable attribute and application of the present invention that these targets should be illustrated as.By using the present invention who discloses in a different manner, perhaps within the scope that discloses, revise the present invention, can obtain many other useful result.Therefore, the scope of the present invention by claim regulation can obtain other targets of the present invention and understanding more fully more in conjunction with the accompanying drawings with reference to content of the present invention and DETAILED DESCRIPTION OF THE PREFERRED.
Summary of the invention
For the purpose of summarizing the present invention, the present invention comprises the method and apparatus that is used for the pressure of control vacuum chamber during the TDM process.
A feature of the present invention provides a kind of method, is used for the anisotropically device of etch substrate.This method comprises following step.Substrate is placed within the plasma chamber, and stands to have the alternate cycles process of etching step and deposition step.Reach predetermined a period of time by choke valve being arranged on the preposition set point, regulate the pressure of plasma chamber, to guarantee when reaching the required time minimization of set-point value not overshoot of chamber pressure or the following operation level that dashes expection.During the deposition step of alternate cycles process, first process gas such as octafluoroization four carbon is introduced in the plasma chamber, is used for film is deposited to substrate.For the deposition step of alternate cycles process, combustion plasm(a) reaches a period of time of method appointment.After predetermined a period of time expiration, enable the closed loop pressure control algolithm.Then, by to carrying out closed loop pressure control the remaining time of deposition step, the pressure of plasma chamber is controlled at the pressure set-point of method appointment.Next step, reach predetermined a period of time by choke valve being arranged on the preposition set point, regulate the pressure of plasma chamber once more, with guarantee make reach the required time minimization of set-point value in, not overshoot of chamber pressure or dash down the operation level of expection.During the etching step of alternate cycles process, second process gas such as sulphur hexafluoride is introduced into plasma chamber, is used for etch substrate.For the etching step of alternate cycles process, combustion plasm(a) reaches a period of time of method appointment.After predetermined a period of time expiration, enable the closed loop pressure control algolithm.Then, by to carrying out closed loop pressure control the remaining time of etching step, the pressure of plasma chamber is controlled at the pressure set-point of method appointment.
The preposition set point can be set up or from following derivation:
1. the throttle valve position of the similar step formerly of alternate cycles process;
2. the average valve location of a plurality of similar steps formerly of alternate cycles process; Perhaps
3. calibration test formerly.
Can regulate about 0.5 to 2 the side-play amount of preposition set point from the throttle valve position of the similar step formerly of alternate cycles process.The preposition set point can use predefined function for predetermined a period of time and change.Based on the pressure of the similar step formerly of alternate cycles process, such as making the required time minimization of pressure set-point that reaches the method appointment, perhaps make from the departing from of pressure set-point of method appointment to minimize and so on, can revise the preposition set point.
The preset time section be approximately 0.05 to 0.5 second so long.Based on the pressure of the similar step formerly of alternate cycles process, such as making the required time minimization of pressure set-point that reaches the method appointment, perhaps make from the departing from of pressure set-point of method appointment to minimize and so on, can revise the preset time section.
Another feature of the present invention provides the compress control method in a kind of time division multiplexed process.This method comprises following step.Reach predetermined a period of time by choke valve being arranged on the preposition set point, in at least one step of time division multiplexed process, regulate the pressure process in the vacuum chamber, with guarantee make reach the required time minimization of set-point value in, not overshoot of chamber pressure or dash down the operation level of expection.At least a process gas is introduced in the vacuum chamber, is used for according to the time division multiplexed process treatment substrate.After the expiration of preset time section, enable the closed loop pressure control algolithm.Then, by to carrying out closed loop pressure control the remaining time of the treatment step of time division multiplexed process, the pressure of vacuum chamber is controlled at the pressure set-point of method appointment.
Another feature of the present invention provides a kind of method, is used for controlling the pressure of vacuum chamber.This method comprises following step.Reach predetermined a period of time by choke valve being arranged on the preposition set point, regulate the pressure process of vacuum chamber, with guarantee make reach the required time minimization of set-point value in, not overshoot of chamber pressure or dash the operation level of expection down.Gas is incorporated in the vacuum chamber.After the expiration of preset time section, enable the closed loop pressure control algolithm.Then, by closed loop pressure control, in vacuum chamber, pressure is controlled at the pressure set-point of method appointment.
The front has been summarized relevant more and important feature of the present invention more widely, so that can understand detailed description of the present invention subsequently better, so that can recognize the contribution to technology more fully.Other feature of the present invention will be described hereinafter, and it has formed the theme of claim of the present invention.Those skilled in the art should recognize that the notion of disclosure can easily be used the basis that makes an amendment or be designed for other structures of carrying out identical purpose of the present invention with specific embodiment.Those skilled in the art should recognize that equally such equivalent constructions does not deviate from the spirit and scope of the present invention, as setting forth in the additional claim.
Description of drawings
Fig. 1 is the end view that shows the primary clustering of plasma processor;
Fig. 2 is for the expecting pressure of the two step TDM processes of moving under the pressure control mode curve chart to time response;
Fig. 3 is for the prior art pressure of the two step TDM processes of moving under the pressure control mode curve chart to time response;
Fig. 4 is for the prior art pressure of the TDM process of moving under the position control mode curve chart to time response;
Fig. 5 is for the prior art pressure of the TDM process of moving under position control mode of the longer time yardstick curve chart to time response;
Fig. 6 is a curve chart of explaining the control system of embodiments of the invention;
Fig. 7 a is a block diagram of explaining the control system of embodiments of the invention;
Fig. 7 b is the continuation of block diagram of Fig. 7 a of explaining the control system of embodiments of the invention;
Fig. 8 is the curve chart of the pressure of the tentative example when carrying out compress control method of the present invention at different input values to the time;
Fig. 9 is the curve chart that shows one optimization in the input value of the present invention;
Figure 10 is the curve chart of the pressure of the tentative example when carrying out compress control method of the present invention at different input values to the time; And
Figure 11 is the curve chart of the pressure of the tentative example when carrying out course control method for use of the present invention to the time, wherein, the etching retention time kept 0.25 second, and the deposition retention time kept 0.40 second, simultaneously, have the fixed position side-play amount of α=0.88 for etching step, and have the fixed position side-play amount of β=1.25 for deposition step.
In whole accompanying drawings, similarly reference number is indicated similar part.
Embodiment
By " keeping and release " method, we disclose the device of the pressure in control TDM or any alternate steps process.When the process step switches to next process steps, pre-aligned choke valve.Executive control system is to be provided with the positional value of pre-aligned choke valve automatically.The throttle valve position of the position that is provided with from the process steps formerly of same type derived.Choke valve keeps predetermined a period of time in the position that is provided with.The retention period after, discharge choke valve, and enable close-loop feedback control algorithm (for example PID ring), to regulate the pressure in the vacuum chamber under the pressure control mode for choke valve.Control system and method have been disclosed.
In Fig. 1, shown according to plasma etching system of the present invention.In the ICP reactor, RF generator 100 is sent electric power to the coil 105 on the top of reative cell 110.This electric power is sent in one or more process gas that are introduced into by the air inlet (not shown), so that one or more process gas of ionization and form plasma 120.RF generator 115 is sent electric power to wafer support 130, and responding to direct current biasing on wafer 125, thereby control is to the direction and the energy of the ion bombardment on wafer 125 surfaces.Evacuation system is got rid of gaseous material (that is unreacting gas, volatile by-product or the like) continuously by exhaust header 150 from reative cell 110.By the pressure in the choke valve conditioned reaction chambers 110 145.Throttle valve controller 140 operated throttle valves 145.Pressure gauge 135 is measured reative cell 110 pressure.The output signal of pressure gauge 135 is presented to throttle valve controller 140 as input.
Fig. 2 has shown the expecting pressure response 200 for the Multiple Cycle 225 of two step TDM processes.The pressure set-point 230 that is used for first step 205 is compared with the pressure set-point 235 that is used for second step 210, needs different throttle valve positions.Because the fast rise time 215 between the step departs from together with the minimum from set point 220 during the process steps, in the TDM process, can expect pressure-responsive fast.
Fig. 3 graphical display have a prior art solution of the throttle valve controller under the pressure control mode.This diagrammatic sketch has shown the curve of the 300 pairs of times of the pressure-responsive with corresponding throttle valve position 305 that are used for two step TDM processes.During the TDM process, this control method causes from the pressure overshoot 325 of the set point 320 of method appointment.The pressure control performance reduced and further reduces along with TDM step 310 retention time.In addition, corresponding throttle valve position 315 steady state position that has never been realized.
Fig. 4 graphical display have a prior art solution that replaces of the throttle valve controller under the position control mode.This diagrammatic sketch has shown the curve of the 400 pairs of times of the pressure-responsive with corresponding throttle valve position 405 that are used for two step TDM processes.This control method is used throttle valve position set point 410﹠amp; 415 are driven into choke valve the position of setting during the TDM process.In this example, notice in the pressure-responsive 420 delay, and never reach the pressure 402 of expection with respect to position set point change.
Fig. 5 graphical display another problem that when position control mode is used to control chamber pressure, runs into.This diagrammatic sketch has shown the curve of the pressure-responsive that is used for two step TDM processes with fixed throttle valve position of two kinds of different air-flows of use in corresponding step to the time.Observe the pressure drift 500 on the long-time process operation (100 repetitions).This pressure drift 500 may be that the wall temperature increase by reative cell causes.Therefore, must take other measure with maintenance process performance reliability and repeatability.
Fig. 6 has shown the curve of the 605 pairs of times of the pressure-responsive with corresponding throttle valve position 600 that are used for two step TDM processes.As early showing, it is difficult that the pressure control of the transition period between the process steps has proved, because pressure overshoot may take place.According to one embodiment of present invention, application site control model in first section 630 of step 610.Choke valve is by pre-aligned and remain on 635 places, position of setting, and always derive from the throttle valve position 620 of the step of formerly carrying out the position 635 of described setting.After first section 630, discharge choke valve from position control mode.Enable the close-loop feedback control algorithm in that, so that to remaining step 610 applying pressure control model.
After completing steps 610, process steps switch to next step 615.During first section 650 of this step 615, choke valve switches to mode position.Choke valve remains on another set point 655, and it is from known throttle valve position 640 derivation of that step of execution formerly.For the application site control model in periods 650 that is provided with, and to this whole period, choke valve remains on the position 655 of setting.The retention period 650 expirations after, discharge choke valve, and by enable the closed loop pressure feedback control algorithm for choke valve, to remaining step 615 applying pressure control model.Selectively, in above-mentioned steps, can be at the pre-aligned choke valve in following position, derive from the mean value of the throttle valve position measured some steps formerly of identical type described position.This has the advantage of removal process to the variation of step.
In many TDM processes, for the retention period 630,650 (see figure 6)s to distribute different time spans be useful.Flexible is position 635,655 in advance, and does not just take from the rearmost position of the choke valve of process steps formerly, is useful equally.According to another embodiment of the invention, independent determine in deposition step and the etching step the retention period, and the positional value in advance of choke valve in independent regulation the retention period.Deriving a kind of method of the regulated value of position 635,655 in advance, is that always oneself formerly uses multiplier in the rearmost position of the choke valve of that step of execution.As shown in Figure 6, this multiplier will cause from the side-play amount 625,645 of the positional value in advance 635,655 of step location value 620,640 formerly.In this way, can be offset pre-aligned throttle valve position, it is greater than or less than from the position of step formerly.
For two step TDM silicon etching processes, in Fig. 7 a and 7b, shown the block diagram illustrating that is used for present embodiment.In Fig. 7 a, the retention time is indicated as " t
Etch hold" 630 and " t
Dep Hold" 650.The step period is indicated as " t
Etch" 610 and " t
Dep" 615.When implementation began, these time spans can be the parts of process approach.And then, be indicated as " location of etch " 620 and " deposition position " 640 from the throttle valve position of step formerly.Be used to keep the position in advance of choke valve to take from etching step formerly in etching period 630, and regulate with factor alpha.Similarly, be used to keep the position in advance of choke valve to take from deposition step formerly in deposition period 650, and regulate with factor beta.The value of α and β can be provided with in process approach by hand, perhaps be provided with automatically by feedback control loop (for example PID), wherein, described feedback control loop is along with the carrying out of process, gaging pressure also uses this information to regulate positional value formerly, so that overshoot minimizes and makes and reaches the required time minimization of set point.Parameter alpha and β typically have the value between 0.5 and 2.0, and it is converted into 50% to 200% of position formerly.For example, be set at α and β under 1.0 the situation, the present invention uses during will be the retention period of etching from throttle valve position value 620 conducts of the etching step of formerly carrying out positional value in advance.
For those skilled in the art will be clearly, all the step application pressure controlling schemes within needn't circulating to the TDM process.Etching keeps the value in length period 630 to be set to zero, allows this method to revert to the art methods of closed loop pressure FEEDBACK CONTROL.Similarly, α and β be set to 1 and etching the retention period 630 length be set under the situation of etching step time 610, allow this method to revert to the art methods of position control mode (open loop pressure control mode).
Pressure control example
For any step of using in the TDM process of the present invention, need specify two parameters for choke valve, that is the amplitude of the duration of retention time and side-play amount.
Fig. 8 pattern exhibiting the tentative example when carrying out course control method for use of the present invention.Effect retention period of having shown the etching of different length.As can seeing,, then take place depositing to etching transition period pressure overshoot if so long less than about 0.1 second etching the retention period.If the retention time be approximately 0.2 to 0.3 second so long, then overshoot almost is eliminated, and is minimized from departing from of pressure set-point 805.Along with the etching retention time is elongated, pressure overshoot occurs in the scope of test once more.This presentation of results, maintenance of the present invention and method for releasing have significantly improved the pressure control performance really.
In another embodiment of the present invention, along with process carries out regulating the position retention time in advance automatically, so that set point overshoot minimizes.Fig. 9 figured be used for two step TDM silicon etching processes from the pressure set point overshoot of the data of Fig. 8 to the relation of position retention time in advance.The feedback control loop of gaging pressure overshoot (for example PID) is along with this information of using of process is regulated the position retention time in advance, so that overshoot minimizes.Similarly, measure the feedback control loop (for example PID) that arrives the set point required time and can regulate the position retention time in advance, minimize so that arrive the set point required time along with this information of using of process.
Figure 10 pattern exhibiting the tentative example when carrying out course control method for use of the present invention.The effect that has shown the pre-aligned side-play amount of the different value that is used for fixing the duration.Locating pressure overshoot in-5% etching holding position adjusting (α=0.95) is minimized.This presentation of results, maintenance of the present invention and method for releasing have significantly improved the pressure control performance really.
Will be clearly to those skilled in the art, the embodiment of explanation can be applied to the rapid cyclic process of multistep that every circulation comprises two or more process steps.The present invention can be applied to equally in the cyclic process (for example Bian Xing TDM process) that changes the step parameter of pressure set-point or additive method appointment during the process within circulation.
Notice that this point is very important, i.e. the present invention also not all needs retention time and position offset for every kind of step type within alternation procedure.An alternative embodiment of the invention can comprise at least a introducing position retention time in the step type within the TDM process.
Figure 11 pattern exhibiting following example, in the described example, attempted the optimal control of the pressure in the two step TDM silicon etching processes.In Figure 11, " t
Etch hold" be 0.25 second, " t
Dep Hold" be 0.4 second, α=0.88, and β=1.25.Compare (seeing Fig. 3,4 and 5) with previous example, significantly improved the pressure outline that during circulation TDM process operation, as a result of obtains, because it has almost become " side ".Pressure is more promptly near set point, and pressure overshoot and following to almost being eliminated.
This disclosure comprises the content that comprises in the accessory claim and the content of above stated specification.Although the present invention is illustrated in its preferred form with particularity to a certain degree, but be appreciated that, just carried out the disclosure of preferred form via example, only otherwise deviate from the spirit and scope of the present invention, can take details and the combination of part and a large amount of variations of arrangement of constructing.
Claims (31)
1. one kind is used for the anisotropically method of the device of etch substrate, and the method includes the steps of:
Make substrate stand the alternate cycles process within plasma chamber, described alternate cycles process has etching step and deposition step;
During the deposition step of described alternate cycles process, in described plasma chamber, introduce first process gas, be used for film is deposited to substrate;
During the etching step of described alternate cycles process, in described plasma chamber, introduce second process gas, be used for etch substrate;
During at least one step of described alternate cycles process,, regulate the pressure of described plasma chamber by choke valve being arranged on a period of time that the preposition set point reaches 0.05 to 0.5 second;
For the deposition step of described alternate cycles process and the etching step of described alternate cycles process, activated plasma reaches a period of time of described method appointment;
After described 0.05 to 0.5 second a period of time expiration, enable the closed loop pressure control algolithm; And
By to carrying out closed loop pressure control the remaining time of step, in described plasma chamber, pressure is controlled at the pressure set-point of described method appointment.
2. according to the process of claim 1 wherein, the preposition set point is set to the throttle valve position of one of step formerly of described alternate cycles process.
3. according to the process of claim 1 wherein, derive the preposition set point from the throttle valve position of one of step formerly of described alternate cycles process.
4. according to the method for claim 3, wherein, derive the preposition set point from the average throttle valve position of a plurality of steps formerly of described alternate cycles process.
5. according to the method for claim 3, wherein, derive the preposition set point from calibration test formerly.
6. according to the method for claim 3, wherein, use is regulated the preposition set point from the side-play amount of the described throttle valve position of described one of step formerly of described alternate cycles process.
7. according to the method for claim 6, wherein, side-play amount is 50% to 200% a change in location from the described throttle valve position of described one of step formerly of described alternate cycles process.
8. according to the process of claim 1 wherein, the preposition set point uses predefined function for described 0.05 to 0.5 second a period of time and changes.
9. according to the process of claim 1 wherein,, revise the preposition set point based on the pressure of one of step formerly of described alternate cycles process.
10. according to the method for claim 9, wherein, to the modification of preposition set point based on the pressure set-point required time that arrives described method appointment is minimized.
11. according to the method for claim 9, wherein, to the modification of preposition set point based on the departing from of pressure set-point from described method appointment minimized.
12. according to the process of claim 1 wherein,, revise described 0.05 to 0.5 second a period of time based on the pressure of one of step formerly of described alternate cycles process.
13. according to the method for claim 12, wherein, to the modification of a period of time of 0.05 to 0.5 second based on the pressure set-point required time that arrives described method appointment is minimized.
14. according to the method for claim 12, wherein, to the modification of a period of time of 0.05 to 0.5 second based on the departing from of pressure set-point from described method appointment minimized.
15. according to the process of claim 1 wherein, described first process gas is octafluoroization four carbon.
16. according to the process of claim 1 wherein, described second process gas is a sulphur hexafluoride.
17. the compress control method in the time division multiplexed process, it comprises following steps:
By choke valve being arranged on a period of time that the preposition set point reaches 0.05 to 0.5 second, at least one step of time division multiplexed process, regulate the pressure process in the vacuum chamber;
In described vacuum chamber, introduce at least a process gas;
After described 0.05 to 0.5 second a period of time expiration, enable the closed loop pressure control algolithm; And
By to carrying out closed loop pressure control the remaining time of the described step of time division multiplexed process, pressure is controlled at the pressure set-point of described method appointment.
18. according to the method for claim 17, wherein, the preposition set point is set to the throttle valve position of one of step formerly of described time division multiplexed process.
19., wherein, derive the preposition set point from the throttle valve position of one of step formerly of described time division multiplexed process according to the method for claim 17.
20., wherein, derive the preposition set point from the average throttle valve position of a plurality of steps formerly of described time division multiplexed process according to the method for claim 19.
21., wherein, derive the preposition set point from calibration test formerly according to the method for claim 19.
22. according to the method for claim 19, wherein, the side-play amount of the described throttle valve position of described one of step formerly of use time division multiplexed process is regulated the preposition set point.
23. according to the method for claim 22, wherein, side-play amount is 50% to 200% a change in location from the described throttle valve position of described one of step formerly of time division multiplexed process.
24. according to the method for claim 17, wherein, the preposition set point uses predefined function for described 0.05 to 0.5 second a period of time and changes.
25., wherein,, revise the preposition set point based on the pressure of one of step formerly of time division multiplexed process according to the method for claim 17.
26. according to the method for claim 25, wherein, to the modification of preposition set point based on the pressure set-point required time that arrives described method appointment is minimized.
27. according to the method for claim 25, wherein, to the modification of preposition set point based on the departing from of pressure set-point from described method appointment minimized.
28., wherein,, revise described 0.05 to 0.5 second a period of time based on the pressure of one of step formerly of time division multiplexed process according to the method for claim 17.
29. according to the method for claim 28, wherein, to the modification of a period of time of 0.05 to 0.5 second based on the pressure set-point required time that arrives described method appointment is minimized.
30. according to the method for claim 28, wherein, to the modification of a period of time of 0.05 to 0.5 second based on the departing from of pressure set-point from described method appointment minimized.
31. a method that is used for controlling the pressure of vacuum chamber, the method includes the steps of:
By choke valve being arranged on a period of time that the preposition set point reaches 0.05 to 0.5 second, regulate the pressure process in the vacuum chamber;
In described vacuum chamber, introduce gas;
After described 0.05 to 0.5 second a period of time expiration, enable the closed loop pressure control algolithm; And
Be controlled at the pressure set-point that in the described vacuum chamber pressure is controlled at described method appointment by closed loop pressure.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US46093203P | 2003-04-07 | 2003-04-07 | |
| US60/460,932 | 2003-04-07 | ||
| US10/815,965 | 2004-03-31 |
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| CN100382249C true CN100382249C (en) | 2008-04-16 |
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| CNB2004800092633A Expired - Lifetime CN100382249C (en) | 2003-04-07 | 2004-04-02 | A method and apparatus for process control in time division multiplexed TDM etch processes |
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| CN112763178B (en) * | 2020-12-25 | 2022-08-26 | 中国空气动力研究与发展中心超高速空气动力研究所 | Hypersonic wind tunnel regulating valve opening degree presetting method capable of automatically stopping in advance |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5803107A (en) * | 1996-03-29 | 1998-09-08 | Lam Research Corporation | Method and apparatus for pressure control in vacuum processors |
| US6142163A (en) * | 1996-03-29 | 2000-11-07 | Lam Research Corporation | Method and apparatus for pressure control in vacuum processors |
| US6431113B1 (en) * | 1999-08-26 | 2002-08-13 | Alcatel | Plasma vacuum substrate treatment process and system |
| US20020117212A1 (en) * | 2000-12-15 | 2002-08-29 | Emmanuel Vyers | Pressure controller and method |
-
2004
- 2004-04-02 TW TW93109202A patent/TWI317537B/en not_active IP Right Cessation
- 2004-04-02 CN CNB2004800092633A patent/CN100382249C/en not_active Expired - Lifetime
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5803107A (en) * | 1996-03-29 | 1998-09-08 | Lam Research Corporation | Method and apparatus for pressure control in vacuum processors |
| US6142163A (en) * | 1996-03-29 | 2000-11-07 | Lam Research Corporation | Method and apparatus for pressure control in vacuum processors |
| US6431113B1 (en) * | 1999-08-26 | 2002-08-13 | Alcatel | Plasma vacuum substrate treatment process and system |
| US20020117212A1 (en) * | 2000-12-15 | 2002-08-29 | Emmanuel Vyers | Pressure controller and method |
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|---|---|
| TWI317537B (en) | 2009-11-21 |
| TW200511423A (en) | 2005-03-16 |
| CN1774796A (en) | 2006-05-17 |
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