JP2001313284A - Method and apparatus for plasma processing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable highly precise surface processing by suppressing the charging damage generated by a device-structure originated cause. SOLUTION: Highly precise etching that is free from charging damage is carried out by restricting voltage potential for a gate oxide film to be low, by operating pulsed discharge by on/off-switching a high-frequency power for plasma generation and controlling inflow quantity of positive charge and of negative charge to sparse areas and dense areas of device patterns by controlling off-time duration of the pulse discharge in which the ratio of electron/ion saturation current is lower than a specified value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing method and apparatus, and more particularly to a plasma processing method and apparatus suitable for surface-treating a semiconductor element or the like using plasma.

[0002]

2. Description of the Related Art Conventionally, for processing a substrate surface of a semiconductor device or the like using plasma, for example, Japanese Patent No. 284
As disclosed in Japanese Patent No. 5163, a positive ion having a sufficient density is generated by an ECR plasma during a discharge time of about 10 μsec, and then a discharge is stopped for 100 μsec to generate a large amount of positive and negative ions. , A 600 kHz RF electric field is applied only when the discharge is OFF, and only positive and negative ions having the same mobility are incident on the substrate, and a plasma that suppresses charge accumulation (charging) generated due to a difference in electron and ion mobilities. Processing methods are known.

[0003] Also, Japanese Patent Publication No. 4-69415 discloses that
The microwave power is periodically modulated to control the distribution of electron temperature in the plasma and the generation ratio of reactive species such as ions and radicals generated in the plasma according to the reaction conditions. There is disclosed a plasma processing apparatus in which a voltage for accelerating incident ions is periodically changed to control an energy distribution of ions incident from a plasma to an object according to a reaction.

Further, Japanese Patent Publication No. 7-66918 and Japanese Patent No. 2538691 disclose a plasma processing apparatus in which the generation timing of a pulsed microwave and an RF bias voltage are synchronized.

[0005]

In recent years, as the degree of integration of semiconductor integrated circuits has increased, for example, the gate oxide film of a MOS (Metal Oxide Semiconductor) transistor, which is a typical example of a semiconductor device, has been reduced in thickness, and the minimum processing size has been reduced. The processing aspect ratio of the device structure increases due to the miniaturization. In such a fine element, electrons having a large random motion component are captured by the pattern due to the mass difference between the electrons and the ions, and cannot reach the groove bottom. Charge. This phenomenon is called electronic shading. In addition, such a phenomenon causes a potential difference between a sparse portion having no pattern and a dense portion having a pattern, thereby causing a problem that a gate oxide film is broken down (charging damage).

The technique described in Japanese Patent No. 2845163 discloses a technique in which an RF electric field of 600 kHz is applied only when discharge is turned off, and only positive and negative ions having the same mobility are incident on the substrate to suppress charge accumulation. I was However, experiments by the inventor have revealed that charging damage affects the amount of electrons / ions flowing into the dense / dense pattern portion. This prior art does not mention the charging damage suppression method intended in the present invention.

Further, Japanese Patent Publication No. 4-69415,
Japanese Patent Publication No. 7-66918 and Japanese Patent No. 253869.
No. 1 does not mention the charging damage suppression method intended in the present invention.

An object of the present invention is to provide a plasma processing method and apparatus capable of suppressing charging damage caused by a device structure and performing high-precision surface processing.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a plasma processing method for processing a substrate by independently controlling the generation of plasma and the incident energy of ions in the plasma to the substrate. This is achieved by providing at least 10 μs after plasma off.

It is another object of the present invention to provide a plasma processing method for processing a substrate by independently controlling the generation of plasma and the incident energy of ions in the plasma on the substrate, wherein the plasma is generated intermittently. This is achieved by providing a time period in which the ratio of the negative current / positive current flowing into the substrate after the plasma is turned off becomes 10 or less.

[0011] It is another object of the present invention to provide a plasma processing method for processing a substrate by independently controlling the generation of plasma and the incident energy of ions in the plasma on the substrate, wherein the plasma is generated at a frequency of 1 kHz to 90 kHz. Intermittently, at least the duty ratio is 10% or more,
This is achieved by providing a time after plasma off of 10 μs.

[0012] Further, the above object is to provide a processing chamber to which a vacuum pumping device is connected and the inside of which can be depressurized, a gas supply device for supplying gas into the processing chamber, and a time-modulated plasma in the processing chamber. In a plasma processing method using a plasma processing apparatus including a plasma generating unit including a high-frequency power supply, a substrate electrode on which a processing target material can be placed, and a bias power supply for supplying high-frequency bias power to the substrate electrode. , The high frequency power supply for plasma generation of the plasma generation means,
The negative current flowing into the substrate during the time modulation period of the plasma /
This is achieved by performing time modulation so that the ratio of the time when the positive current ratio is 10 or less occupies 40% or more.

The object of the present invention is also to provide a processing chamber to which a vacuum pumping device is connected and whose inside can be depressurized, a gas supply device for supplying a gas into the processing chamber, and a time-modulated plasma in the processing chamber. In a plasma processing apparatus including a plasma generation unit including a high-frequency power supply, a substrate electrode on which a material to be processed can be placed, and a bias power supply for supplying high-frequency bias power to the substrate electrode, This is achieved by time-modulating the high frequency power supply for use so that the ratio of the time during which the negative current / positive current flowing into the substrate is 10 or less occupies 40% or more during the time modulation cycle of the plasma.

Further, the repetition frequency of the high frequency power supply for plasma generation is 1 kHz to 90 kHz and the pulse duty ratio is 60% or less.

Further, the high frequency bias power supplied to the substrate is time-modulated at a repetition frequency of 1 kHz or more and a duty ratio of 60% or less.

It is another object of the present invention to provide a processing chamber to which a vacuum pumping device is connected, the inside of which can be depressurized, a gas supply device for supplying gas into the processing chamber, and a high-frequency wave for generating time-modulated plasma in the processing chamber. In a plasma processing apparatus including a plasma generation unit including a power supply, a target material, a substrate electrode on which the target material can be mounted, and a high-frequency bias power supply for supplying high-frequency power to the substrate electrode, This is achieved by time-modulating the plasma-generating high-frequency power supply so that the ratio of the time during which the negative current and the positive current flowing into the substrate are equal during the modulation period is 20% or more.

Further, the repetition frequency of the high frequency power supply for plasma generation is set to 1 kHz to 90 kHz, and the pulse duty ratio is set to 60% or less.

Further, the high frequency bias power is time-modulated at a repetition frequency of 1 kHz or more and a duty ratio of 60% or less.

The above object is also achieved by a plasma processing method for processing a substrate by independently controlling the generation of plasma and the incident energy of ions in the plasma to the substrate, wherein the plasma is generated at a frequency of 1 kHz to 90 kHz. Intermittently, at least the duty ratio is 10% or more,
This can be achieved by providing a time of 10 μs after the plasma is turned off and time-modulating a bias voltage for controlling the incident energy of ions.

Further, the time modulation of the bias voltage is synchronized with the cycle of plasma generation.

The object of the present invention is to turn on / off the high frequency power for plasma generation to perform a pulse discharge, to control the off time of the pulse discharge to be equal to or less than a predetermined electron / ion saturation current ratio, and to make the device pattern sparse and dense. This is achieved by controlling the amount of positive and negative charges flowing into the section to suppress charging damage.

In the plasma processing apparatus of the present invention, by turning on / off the supplied high frequency power for plasma generation and controlling the off time, the amount of positive and negative charges flowing into the sparse / dense part of the device pattern is reduced. By controlling the ratio and keeping the voltage generated in the gate oxide film low, the occurrence of charging damage can be suppressed. Thereby, highly accurate etching can be performed.

[0023]

[Embodiment 1] Hereinafter, the first embodiment of the present invention will be described.
Will be described with reference to FIGS. 1 to 7. FIG. FIG. 1 shows a microwave plasma etching apparatus which is an embodiment of the plasma processing apparatus of the present invention. A dielectric window 102 (for example, a quartz window) is provided on the upper portion of the vacuum container 101 whose upper portion is open and sealed. A vacuum exhaust port 10 is provided below the vacuum vessel 101.
A vacuum evacuation device (not shown) is connected to the vacuum container 101 via a gas supply device 3. A waveguide 107 and a magnetron 106 are sequentially connected to the upper portion of the vacuum vessel 101 via a dielectric window 102, and the magnetron 106 is connected to a microwave power supply 105 constituting a high-frequency power supply for generating plasma together with the magnetron. . The microwave power supply 105 turns on / off the microwave output at an arbitrary frequency and a duty ratio. Upper outer peripheral portion of vacuum vessel 101 and waveguide 107
A magnetic field generating coil 108 for generating a magnetic field in the vacuum vessel 101 is wound around a part of the outer periphery of the vacuum container 101.

On the other hand, the substrate electrode 109 on which the material to be processed 112 can be placed is installed below the vacuum vessel 101 and is connected via a matching box 110 to a high frequency power supply 111 which is a bias power supply. The high-frequency power supply 111 supplies high-frequency power (for example, a frequency of 400 kHz) to the substrate electrode 109.
z, 800 kHz, 2 MHz, etc.), and can be oscillated with time modulation.

To perform the plasma etching process in the apparatus configured as described above, first, the vacuum vessel 10
After the pressure in the chamber 1 is reduced by a vacuum exhaust device (not shown), an etching gas is introduced from the gas supply device 104 into the vacuum chamber 101 and adjusted to a desired pressure. Next, a high frequency power supply for plasma generation, that is, a microwave power supply 105
For example, the microwave of 2.45 GHz oscillated by the magnetron 106 propagates through the waveguide 107 and is introduced into the vacuum chamber 101 through the dielectric window 102. This microwave power is supplied to the magnetic field generating coil 108.
Interaction with a magnetic field of, for example, 875 G generated by the above process efficiently ionizes the gas in the vacuum vessel 101 to generate plasma.

It should be noted that charging damage due to electron shading occurs due to the non-uniformity of the positive and negative charges flowing into the dense and sparse portions of the device pattern. In the present embodiment, charging damage can be reduced by performing on / off control of a microwave pulse supplied from a high frequency power supply for plasma generation and performing pulse discharge.

FIG. 2 shows ON / OFF waveforms of pulse discharge by the high frequency power supply for plasma generation. The pulse on / off waveform 201 is a repetitive waveform having a period 202. The pulse-on time 203 / pulse cycle 202 × 100 is called a duty ratio, and the reciprocal of the cycle 202 is called a repetition frequency. In this case, a frequency band of 1 kHz to 100 kHz is used.

Next, the effect of the pulse discharge by the high frequency power supply for plasma generation will be described with reference to FIGS. FIG. 3 shows the time change of the ion and electron saturation currents incident on the device pattern at the time of pulse discharge. The vertical axis represents the saturation current on a logarithmic scale, and the horizontal axis represents time. In this case, the cycle of the pulse discharge is 10 kHz, and the ratio of the pulse on and the pulse off in FIG.
It is shown at 0%. During the pulse-on period, the electron saturation current 3
Although the difference between 01 and the ion saturation current 302 is large, the electron saturation current 301 rapidly decreases at the same time as the pulse is turned off, and thereafter, during the time τ, the electron saturation current 301 and the ion saturation current 302 become equal. Time τ in one cycle in this case
Was about 20%.

FIG. 4 shows the change over time of the electron / ion saturation current ratio (negative current / positive current ratio) incident on the sparse and dense portions of the pattern when pulse discharge is performed. The vertical axis represents the electron / ion saturation current ratio on a logarithmic scale, and the horizontal axis represents time. In this case, the cycle of the pulse discharge is 10 kHz, and the ratio of pulse on and pulse off in FIG. 4 is shown as 50%. During the pulse-on period, the electron / ion saturation current ratio 501 incident on the sparse portion is larger than the electron / ion saturation current ratio 502 incident on the dense portion, but the difference decreases sharply as soon as the pulse is turned off. Department
The electron / ion saturation current ratio approaches 1 during time τ in both dense areas. In this case, the ratio of the time τ in one cycle was approximately 20%. Also, after the pulse is turned off, after the time when the electron / ion saturation current ratio becomes 10 or less, that is, after about 1/10 of one cycle time after the pulse is turned off, the electron / ion flowing into the coarse portion and the dense portion is returned. The saturation current ratios are almost the same. From this, that is, in the pulse discharge, the electron / ion saturation current ratio after the pulse is turned off is 1
After the time when it becomes 0 or less, the difference in the electron / ion saturation current ratio between the sparse part and the dense part during the pulse-off period is small, so that a voltage is not generated in the gate oxide film and the charging damage is reduced. There is an effect that can be.

For comparison, FIG. 5 shows the change over time of the electron / ion saturation current ratio incident on the sparse and dense portions of the pattern during continuous discharge. The vertical axis represents the electron / ion saturation current ratio on a logarithmic scale, and the horizontal axis represents time. The electron / ion saturation current ratio 402 incident on the dense portion is smaller than the electron / ion saturation current ratio 401 incident on the sparse portion. this is,
This is because the number of electrons incident on the dense portion is reduced by electron shading. That is, the difference in the amount of charge incident on the sparse and dense portions of the pattern as shown in FIG. 5 causes charging damage. On the other hand, in the pulse discharge according to the present embodiment, since the difference in the amount of charge incident on the sparse and dense portions of the pattern during the pulse-off period is small, charging damage can be reduced.

FIG. 6 shows the relationship between the ratio of the time τ during which the electron / ion saturation current ratio becomes 1 during the pulse-off period per pulse period and the voltage generated in the gate oxide film. The pulse period is 10 kHz. The vertical axis is voltage, the horizontal axis is time τ
And the ratio per cycle is shown, and both axes are equally divided. The gate oxide film voltage 601 decreases as the ratio of time τ per cycle increases. For example, if the ratio of time τ per pulse period is 20% or less, a voltage higher than the breakdown voltage 602 (6 V in this case) of the gate oxide film is applied to the gate oxide film. Is 20% or more, in other words, by setting the time τ to 20 μs or more, the gate oxide film voltage can be suppressed to the gate breakdown voltage 602 or less. Thereby, charging damage can be suppressed.

Here, referring to FIG. 4, the above condition corresponds to setting the ratio of the time when the electron / ion saturation current ratio is 10 or less per pulse period to 40% or more. Therefore, the pulse repetition frequency and the duty ratio of the high frequency power supply for plasma generation are adjusted to increase the ratio of the time τ per pulse or the period of time during which the electron / ion saturation current ratio becomes 10 or less per pulse. Thereby, charging damage can be reduced, and there is an effect that highly accurate etching can be performed.

Further, the above condition is such that the pulse repetition frequency is 1
It is effective within a range of kHz to 90 kHz and a duty ratio of 60% or less. For example, when the pulse frequency is as low as 1 kHz, the time of one cycle becomes longer, so that a sufficient pulse-off time can be provided even if the duty ratio is larger than 50%. By the way, frequency 1kHz
In the case of z, the pulse off time is 600 μsec at a duty ratio of 60%. Therefore, considering the time after the pulse is turned off, the duty ratio can be made larger than 60%. However, if the time during the pulse on is long, the charge time is long, and the gate oxide film breakdown voltage (for example, 6 V) is reached. When the frequency is 1 kHz, the duty ratio is desirably 60% or less.

Conversely, when the pulse frequency becomes high, such as 50 kHz, the period of one cycle is shortened, so that it can be implemented by making the duty ratio smaller than 50% to secure the pulse off time. Incidentally, a 10% duty ratio is required for plasma generation, and a time of at least 10 μs is required to reduce the difference in the electron / ion saturation current ratio after the plasma is turned off. Therefore, the pulse discharge cycle in this case is It is about 90 kHz. Therefore, in this embodiment, the pulse repetition frequency is from 1 kHz to 90 kHz.
z and the duty ratio are effective within the range of 60% or less.

The above-described effect of reducing the charging damage is further improved by time-modulating and supplying the high-frequency bias power to the substrate. FIG. 7 shows the pulse duty ratio dependence of 701 when a continuous bias is applied to the substrate and 702 when a time modulation (TM) bias (in this case, a power supply frequency of 400 kHz, a repetition frequency of 2 kHz, and a duty ratio of 40%) is applied. Is shown. The vertical axis represents the voltage applied to the gate oxide film, and the horizontal axis represents the duty ratio of the pulse discharge. Both scales are equally divided.
The pulse discharge cycle in this case is 10 kHz.

As is apparent from FIG. 7, the continuous bias,
In both the time modulation (TM) bias, when the pulse duty ratio is reduced so that the time τ becomes longer, the voltage generated in the gate oxide film decreases. Further, the gate oxide film voltage is lower in the case 702 when the applied bias is time-modulated than in the case 701 when the continuous bias is applied. This is because, in the case of the continuous bias, the ions in the plasma are continuously drawn into the substrate, so that the saturation current ratio of electrons / ions becomes large. This is probably because the incidence is reduced and the electron / ion saturation current ratio is prevented from increasing.

In the time modulation bias, the pulse discharge cycle is synchronized with the cycle of the time modulation bias, and when the pulse discharge is on, the time modulation bias is also turned on to further reduce the voltage generated in the gate oxide film. Can be lowered. This is because in the off time of the pulse discharge, in the case of a continuous bias, the ions of the plasma that are attenuating after the pulse is turned off are incident on the substrate,
It is considered that the time modulation bias has no effect of causing ions in the plasma to be incident on the substrate after the pulse discharge, and thus the electron / ion saturation current ratio is rapidly reduced in the dense / dense area on the substrate surface as shown in FIG.

Further, the repetition frequency of the time modulation bias is a phenomenon in which the time of charge-up and decay is about 1 ms, so that a period earlier than this is necessary.
A repetition frequency of 1 kHz or more is required. The frequency of the bias power supply is not particularly limited, but the upper limit of the repetition frequency needs to be 以下 or less of the power supply frequency.

As described above, according to the present embodiment, the high-frequency power for plasma generation is turned on and off to perform pulse discharge, and the off-time of the pulse discharge at or below a predetermined electron / ion saturation current ratio is controlled, whereby the device Since the amount of positive and negative charges flowing into the sparse and dense portions of the pattern can be controlled and the potential of the gate oxide film can be suppressed low, there is an effect that highly accurate etching without charging damage can be performed.

When a high-frequency bias is applied to a substrate having a portion to be etched of a dense / dense pattern to perform a plasma process, the pulse repetition frequency and the duty ratio are adjusted so that the time τ at which the electron / ion saturation current ratio becomes 1 or the pattern sparse / dense is obtained. The charging damage can be reduced by increasing the ratio per pulse period of 1/10 or less of the electron / ion saturation current ratio at which the difference in the electron / ion saturation current ratio of the portion becomes small. In addition, by using the time modulation bias in combination with the pulse discharge or using it in synchronization, the voltage generated in the gate oxide film can be further reduced, the charging damage is reduced, and a highly accurate etching process is performed. There is an effect that it can be made possible.

Embodiment 2 FIG. 8 shows a second embodiment of the present invention.
This will be described with reference to FIG. In this figure, the same reference numerals as in FIG. 1 denote the same members, and a description thereof will be omitted. The difference between this figure and FIG. 1 will be described below. The upper part of the vacuum vessel 101 is
(For example, quartz) and the upper electrode 802 (for example, Si
Made). The upper electrode 802 has a multi-hole structure for flowing an etching gas, and is connected to the gas supply device 104. High-frequency power of, for example, 450 MHz oscillated from the electromagnetic wave source 806 is supplied to a high-pass filter 805.
, And 13.56 MHz high-frequency power oscillated from the antenna bias power supply 808 are transmitted to the tuner 804 via the low-pass filter 807, respectively, and passed through the coaxial line 803 to the dielectric window 801 and the upper electrode 802. And propagates into the vacuum vessel 101 through
Generates plasma. Further, an electromagnetic wave source 806 as a high frequency power supply for plasma generation and an antenna bias power supply 8
08 is capable of pulse modulation oscillation. On the other hand, the substrate electrode 109 is connected to a high frequency power supply 111 as a bias power supply. Also in the apparatus configured as in the present embodiment, the amount of positive and negative charges flowing into the sparse and dense portions of the pattern is controlled by performing pulse discharge and time modulation bias in the same manner as in the first embodiment. Since the gate oxide film potential can be suppressed low, there is an effect that highly accurate etching without charging damage can be performed.

[Embodiment 3] FIG. 9 shows a third embodiment of the present invention.
This will be described with reference to FIG. In this figure, the same reference numerals as in FIG. 1 denote the same members, and a description thereof will be omitted. The difference between this figure and FIG. 1 will be described below. The upper portion of the vacuum vessel 101 is sealed with a dielectric window 801 (for example, made of quartz) and an upper electrode 802 (for example, made of Si). The upper electrode 802 has a multi-hole structure for flowing an etching gas, and is connected to the gas supply device 104. Electromagnetic wave source 9 as high frequency power supply for plasma generation
03, for example, 27MHz or 60M
The high frequency power of Hz propagates through the upper electrode 802 into the vacuum chamber 101 to generate plasma. Further, the electromagnetic wave source 903 can perform pulse modulation oscillation. On the other hand, the substrate electrode 109 is connected to a high frequency power supply 111 as a bias power supply. Also in the apparatus configured as in the present embodiment, the amount of positive and negative charges flowing into the sparse and dense portions of the pattern is controlled by performing pulse discharge and time modulation bias in the same manner as in the first embodiment. Since the gate oxide film potential can be suppressed low, there is an effect that highly accurate etching without charging damage can be performed.

A fourth embodiment of the present invention will be described with reference to FIG. In this figure, the same reference numerals as in FIG. 1 denote the same members, and a description thereof will be omitted. The difference between this figure and FIG. 1 will be described below.
The upper part of the vacuum vessel 101 is sealed with a dielectric window 102. A loop antenna 901 is provided above the dielectric window 102. For example, an antenna power supply 90 of 13.56 MHz is provided.
2 are connected. High frequency power is supplied from the loop antenna 901 through the dielectric window 102 into the vacuum vessel 101 to generate plasma. Here, the antenna power supply 902 as the high frequency power supply for plasma generation can perform pulse modulation oscillation. On the other hand, the substrate electrode 109 is connected to a high frequency power supply 111 as a bias power supply. Also in the apparatus configured as in the present embodiment, the amount of positive and negative charges flowing into the sparse and dense portions of the pattern is controlled by performing pulse discharge and time modulation bias in the same manner as in the first embodiment. Since the gate oxide film potential can be suppressed low, there is an effect that highly accurate etching without charging damage can be performed.

In the above embodiments, the etching apparatus has been described. However, the present invention may be applied to other plasma processing apparatuses such as an ashing apparatus and a CVD apparatus.

[0045]

As described above, according to the present invention, the ratio of the period of time τ during which the electron / ion saturation current ratio during the pulse-off period becomes 1 per cycle or the difference between the electron / ion saturation current ratios in the dense / dense pattern portion is small. The pulse discharge condition is controlled so that the ratio of the period of the electron / ion saturation current ratio of 10 or less per one pulse period is high, that is, the time of the predetermined electron / ion saturation current ratio or less is long. Accordingly, there is an effect that charging damage generated by electron shading can be suppressed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an etching apparatus according to a first embodiment using the present invention.

FIG. 2 is a diagram showing an example of an ON / OFF waveform of a pulse discharge in the embodiment of FIG.

FIG. 3 is a diagram showing a change over time of an ion / electron saturation current incident on a pattern at the time of pulse discharge in the embodiment of FIG. 1;

FIG. 4 is a diagram showing a change over time in an ion / electron saturation current ratio incident on a pattern at the time of pulse discharge in the embodiment of FIG. 1;

FIG. 5 is a diagram showing a change over time of an ion / electron saturation current ratio incident on a pattern during continuous discharge in a conventional device shown for comparison.

FIG. 6 is a diagram showing a time τ dependency of a gate oxide film voltage in the embodiment of FIG. 1;

FIG. 7 is a diagram showing a pulse duty ratio dependency of a gate oxide film voltage when a bias is applied in the embodiment of FIG. 1;

FIG. 8 is a longitudinal sectional view showing an etching apparatus according to a second embodiment of the present invention.

FIG. 9 is a longitudinal sectional view showing an etching apparatus according to a third embodiment using the present invention.

FIG. 10 is a longitudinal sectional view showing an etching apparatus according to a fourth embodiment using the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 101 ... vacuum container, 102 ... dielectric window, 103 ... vacuum exhaust port, 104 ... gas supply apparatus, 105 ... microwave power supply, 106 ... magnetron, 107 ... waveguide, 108 ...
Magnetic field generating coil, 109: substrate electrode, 110: matching box, 111: high-frequency power supply, 112: workpiece, 201: pulse on / off waveform, 202: cycle, 20
3: pulse on time, 301: electron saturation current, 302:
Ion saturation current, 401,501: electron / ion saturation current ratio incident on a sparse portion, 402,502: electron / ion saturation current ratio incident on a dense portion, 601: gate oxide film voltage,
602: gate oxide breakdown voltage; 701: gate oxide voltage when a continuous bias is applied; 702: gate oxide film voltage when a time modulation bias is applied; 801: dielectric window;
Upper electrode, 803: Coaxial line, 804: Tuner, 8
05, 807: filter, 806: electromagnetic wave source, 808
... antenna bias power supply, 901 ... loop antenna, 9
02: antenna power supply, 903: electromagnetic wave source.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) H05H 1/46 H01L 21/30 572A

Claims (13)

[Claims] 1. A plasma processing method for processing a substrate by independently controlling the generation of plasma and the incident energy of ions in the plasma to the substrate, wherein the plasma is generated intermittently and at least the plasma is turned off. A plasma processing method characterized by providing a later time of 10 μs. 2. A plasma processing method for processing a substrate by independently controlling the generation of plasma and the incident energy of ions in the plasma on the substrate, wherein the plasma is generated intermittently and at least the plasma is turned off. The ratio of the negative current / positive current flowing into the substrate later is 10
A plasma processing method characterized by providing the following time. 3. A plasma processing method for processing a substrate by independently controlling generation of plasma and incident energy of ions in the plasma on the substrate, wherein the generation of the plasma is intermittently performed at a period of 1 kHz to 90 kHz. Wherein the duty ratio is at least 10% and the time after plasma is turned off is provided for 10 μs. 4. A processing chamber to which a vacuum pumping device is connected and whose inside can be depressurized, a gas supply device for supplying gas into the processing chamber, and a high-frequency power supply for generating time-modulated plasma in the processing chamber. The plasma processing method according to claim 1, further comprising: a plasma generating unit including a plasma generating unit, a substrate electrode on which a target material can be placed, and a bias power supply for supplying high-frequency bias power to the substrate electrode. The high frequency power supply for plasma generation of the generation means,
The negative current flowing into the substrate during the time modulation period of the plasma /
A plasma processing method characterized in that time modulation is performed so that the ratio of the time when the positive current ratio is 10 or less is 40% or more. 5. A processing chamber to which a vacuum evacuation device is connected and whose inside can be decompressed, a gas supply device for supplying a gas into the processing chamber, and a high-frequency power supply for generating time-modulated plasma in the processing chamber. A plasma processing apparatus comprising: a plasma generating means including a plasma generating means, a substrate electrode on which a material to be processed can be placed, and a bias power supply for supplying a high frequency bias power to the substrate electrode; Power supply
The negative current flowing into the substrate during the time modulation period of the plasma /
A plasma processing apparatus, wherein time modulation is performed so that a ratio of a time when a positive current ratio is 10 or less is 40% or more. 6. The plasma processing apparatus according to claim 5, wherein a repetition frequency of said high frequency power supply for plasma generation is 1 kHz to 90 kHz and a pulse duty ratio is 60% or less. 7. The plasma processing apparatus according to claim 5, wherein the high frequency bias power supplied to the substrate is:
Repetition frequency 1 kHz or more and duty ratio 60
%. Time-modulated at less than%. 8. A processing chamber to which a vacuum evacuation device is connected and whose inside can be decompressed, a gas supply device for supplying gas into the processing chamber,
A plasma generating means including a high-frequency power supply for generating time-modulated plasma in the processing chamber, a material to be processed, a substrate electrode on which the material to be processed can be mounted, and a high-frequency power supply to the substrate electrode In a plasma processing apparatus equipped with a high-frequency bias power supply of
A plasma processing apparatus, wherein the high frequency power supply for plasma generation is time-modulated so that a ratio of a time when a negative current and a positive current flowing into a substrate occupy are equal to or more than 20%. 9. The plasma processing apparatus according to claim 8, wherein the repetition frequency of the high frequency power supply for plasma generation is 1 kHz to 90 kHz and the pulse duty ratio is 6 kHz.
A plasma processing apparatus characterized by being at most 0%. 10. The plasma processing apparatus according to claim 8, wherein said high-frequency bias power is time-modulated at a repetition frequency of 1 kHz or more and a duty ratio of 60% or less. 11. A plasma processing method for processing a substrate by independently controlling generation of plasma and incident energy of ions in the plasma on the substrate, wherein the generation of the plasma is intermittently performed at a period of 1 kHz to 90 kHz. Wherein the duty ratio is at least 10%, the time after plasma is turned off is 10 μs, and the bias voltage for controlling the ion incident energy is time-modulated. 12. The plasma processing method according to claim 12, wherein the time modulation of the bias voltage is synchronized with a cycle of the plasma generation. 13. A pulse discharge is performed by turning on / off the high frequency power for plasma generation, controlling the off time of the pulse discharge at or below a predetermined electron / ion saturation current ratio, and controlling the off time of the device pattern sparse part / dense part. A plasma processing method comprising controlling the inflow of positive charges and negative charges to suppress charging damage.