JP2001085393A - Surface working method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a partial etching residue of a metal film and a barrier film while a semiconductor film is left alone, by allowing a sample temperature to be a specified value when etching with plasma a metal film of a multi-layer film which comprises a metal film, a barrier film, and a semiconductor film. SOLUTION: A sample 106 which comprises a multi-layer film comprising a metal film, a barrier film, and a semiconductor film is sucked to a sample stage 108 while a plasma 105 is generated with an inert gas to raise the temperature of the sample. After confirming with a temperature sensor 107 that a sample temperature is 100-200 deg.C or above, a plasma 105 is generated to etch the metal film and the barrier film up to the upper layer part of the semiconductor film. With etching using the plasma 105 at a high temperature, the etching speed of the metal film is raised while that of the semiconductor film is not raised. Thus, the semiconductor film is left alone with no partial etching residue for the metal film or barrier film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for processing a surface of a semiconductor device, and more particularly, to a method for processing a surface using plasma.

[0002]

2. Description of the Related Art An apparatus utilizing plasma is widely used for etching a semiconductor element. The present invention is applied to an apparatus using such a plasma. Conventionally, as plasma for etching a tungsten film, Yasuo Tarui General Supervision: Semiconductor Process Handbook: (p92
-93): As described in Press Journal Co., Ltd., a fluorine-based gas, a chlorine-based gas, a bromine-based gas, or a mixed gas thereof was used.

[0003] Also, for the purpose of mainly improving the precision of processing, Japanese Patent Application Laid-Open No. 6-151360 (corresponding to US Pat.
352, 324) is known. By controlling the high-frequency voltage applied to the sample on and off intermittently, the selectivity between silicon (Si), which is the substance to be etched, and the base oxide film can be increased, and the aspect ratio dependency can be reduced. Also, JP-A-8-339989 (corresponding to US Pat. No. 5,614,06)
No. 0) describes that the etching residue can be reduced by superimposing intermittent rf bias power short pulses in metal etching.

[0004]

With the speeding up and lower power consumption of semiconductor devices, it is necessary to lower the resistance of conductors such as electrodes and wirings. For this reason, MOS (Metal Oxide Semico
In order to form a gate electrode of an nductor element, there is a structure in which a polycrystalline silicon film is formed on a silicon oxide film, and a tungsten film is formed thereon. Further, a barrier film such as a tungsten nitride film is required between the polycrystalline silicon film and the tungsten film in order to suppress mutual diffusion.

When a film having a multilayer structure as described above is etched, there arises an unconventional problem due to a difference in etching reaction between polycrystalline silicon and tungsten. For example, when a fluorine-based gas is used as the etching gas, it is difficult to suppress the etching rate of the polycrystalline silicon film after etching the tungsten film because the etching rate of the polycrystalline silicon is high. As a result, the silicon oxide film is etched.
Alternatively, when a chlorine-based gas is used as an etching gas, the tungsten etching rate is low, so that a tungsten film or a barrier film partially remains on polycrystalline silicon, causing problems such as unevenness on an etching surface. . As a means for increasing the etching rate of the tungsten film by the chlorine-based gas plasma, it is known that the improvement can be achieved by increasing the sample temperature. However, when the polycrystalline silicon film is etched after the tungsten film is etched, the sample temperature is increased. Since the etching is high, there is a problem that etching progresses isotropically and side etching occurs.

[0006] Among the damages (hereinafter referred to as charge-up damages) caused by charges such as ions and electrons in the plasma generated on the wafer in a semiconductor processing process using plasma, the problem of microscopic damage is large. It has become to. This is because when the etching of the sparse part of the pattern is completed and it is electrically separated from other parts, the positive potential charged in the dense part that has not been etched yet is applied to the gate oxide film and the gate insulation film is insulated. Is to cause destruction. Since the time from the end of etching of a relatively sparse portion of a pattern to the end of etching of a dense portion becomes long, microscopic charge-up damage increases. This time is due to the difference in etching rate between the sparse part and the dense part of the pattern.

The object of the present invention is to solve these problems,
An object of the present invention is to provide a method for processing a sample surface suitable for processing a sample having a multilayer film including at least a metal film and a semiconductor film deposited on a semiconductor substrate.

[0008]

In order to solve the above-mentioned problems, the present invention is characterized in that a vacuum vessel, a means for generating plasma therein, and a sample table on which a sample to be surface-processed by the plasma are provided. Using a temperature control mechanism for controlling the temperature of the sample stage, and a surface processing apparatus including a power supply for applying a high-frequency voltage to the sample stage, a multilayer including at least a metal film and a semiconductor film deposited on a semiconductor substrate. In the processing of feed having a film, the sample temperature was set to 10 when processing the metal film.
It is to keep the temperature between 0 ° C and 200 ° C.

In the present invention, the etching rate of the metal film is increased by maintaining the sample temperature at 100 ° C. or more and 200 ° C. or less during the etching of the metal film.

According to another feature of the present invention, oxygen gas is added to the gas containing a halogen element in order to suppress the etching rate of the polycrystalline silicon film and prevent side etching.

According to another feature of the present invention, the process of processing the multilayer film is divided into a plurality of steps having different sample temperatures. That is, in order to suppress the etching rate of the silicon oxide film during the etching of the polycrystalline silicon film, the processing is performed at least separately for the metal film etching conditions and the polycrystalline silicon film etching conditions.

According to another feature of the present invention, a high rf bias can be applied to the tungsten film by turning on / off the high-frequency power supply at the time of etching the tungsten film. It is possible to reduce the difference in etching rate between the sparse portion and the portion.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 First, Embodiment 1 will be described. FIG. 1A
FIG. 1 is a configuration diagram of an etching processing chamber of a plasma etching apparatus to which the present invention is applied, and FIG. 1B is a diagram showing a detailed structure of a sample stage portion of FIG. 1A. Microwaves are introduced from a microwave power supply 101 into a vacuum vessel 110 via a waveguide 102 and a quartz plate 103. Around the vacuum vessel 110,
An electromagnet 104 is provided, and has a structure in which a plasma 105 is generated using electron cyclotron resonance by a magnetic field and a microwave. The sample 106 is the dielectric film 10
9 is provided on the sample stage 108. Also,
The sample stage 108 has a high frequency power supply 112 and a DC power supply 113 and a refrigerant temperature controller 111 for adjusting the temperature of the sample stage.
Is connected. The refrigerant temperature controller 111 controls the temperature of the sample stage by adjusting the flow rate of the refrigerant circulating in the gap provided in the sample stage. A DC voltage applied by a DC power supply 113 generates a Coulomb force between the dielectric film 109 and the sample 106 to move the sample 106 to the sample stage 108.
And the temperature of the sample 106 is controlled. Further, a temperature sensor 107 is provided on the sample stage 108 so that the temperature of the sample 106 can be monitored.

As shown in FIG. 1B, the sample stage is covered with a dielectric film 109 on the sample placement side and an insulating plate 118 on the back side, and a gap between the intermediate electrode member 121 and the lower electrode member 122 is provided. 123, refrigerant introduction nozzle 117, pipe 120
The heated or cooled refrigerant is circulated through the cooling medium. The temperature of the intermediate electrode member 125 is controlled by controlling the temperature and the circulation amount of the refrigerant by the refrigerant temperature controller 111. The high-frequency power supply 112 and the DC power supply 113 are applied to the lower electrode via a shaft 115 coated on the insulating film 116. Further, the upper electrode member 1 provided with the dielectric film 109
25 has a gap 124 into which an inert gas such as helium gas is introduced via a conduit having a valve 114. This inert gas is supplied to the upper electrode member 12.
5 facilitates heat conduction from the sample 5 to the sample 106 placed thereon.

The temperature monitor of the temperature sensor 107 makes it possible to start etching after the temperature of the sample 106 reaches a desired temperature or to detect an abnormality in the temperature of the sample during the etching process.

FIG. 2 is a cross-sectional view of the sample. In an initial state, an oxide film 2 is formed on a silicon substrate 206 as shown in FIG.
05, polycrystalline silicon film 204, tungsten nitride film 2
03, a mask 201 processed into a desired pattern is formed on the uppermost layer of a multilayer film of the tungsten film 202.

Next, a specific processing procedure of the first embodiment will be described. On the sample stage 108 heated to 150 ° C. by the refrigerant temperature controller 111 which is a sample stage temperature adjustment mechanism,
The sample 106 is placed, and the sample 106 is adsorbed on the sample stage 108 by a DC voltage applied by a DC power supply 113, and at the same time, an inert gas of argon or helium is used.
A plasma 105 is generated to raise the temperature of the sample 106,
After the temperature sensor 107 confirms that the sample temperature is a desired temperature, the plasma 105 is turned off. After that, the gas is changed, a high frequency power supply 112 is applied simultaneously with the generation of the plasma 105, and ions incident on the sample 106 are accelerated to etch the upper layers of the tungsten film 202, the tungsten nitride film 203, and the polycrystalline silicon film 204, FIG. 2 (b)
Process up to state. The etching gas at that time was chlorine 40 ml / min, oxygen 10 ml / min, pressure 0.2 Pa,
The microwave power was 500 w, the sample temperature was 150 ° C., and the high frequency power was 100 w.

FIG. 5A shows an example in which the sample temperature dependence of the etching rate of a tungsten film, a polycrystalline silicon film, and an oxide film was examined using chlorine and oxygen as etching gases.
As described above, by etching with plasma of chlorine and oxygen at a high temperature, the etching rate of the tungsten film can be increased without increasing the etching rate of the polycrystalline silicon film. Therefore, the polycrystalline silicon film can be left without the partial etching residue of the tungsten film or tungsten nitride.

Next, hydrogen bromide 10 is used as an etching gas.
0 ml / min, oxygen 5 ml / min, pressure 1 Pa, microwave power 500 w, sample temperature 150 ° C., high frequency power 30
The processing is performed up to the state of FIG.

As in this embodiment, the tungsten film is
By etching at a high temperature of 0 ° C. or more, a polycrystalline silicon film can be left without etching residue of a tungsten film or a barrier film. Therefore, switching to a condition that allows the polycrystalline silicon film to be etched with high selectivity with respect to the oxide film,
High-precision processing is possible.

(Embodiment 2) Next, as Embodiment 2, an example in which the multilayer film is processed using the plasma etching apparatus shown in FIG. The coolant cooled to 20 ° C. by the coolant temperature controller 111 is circulated to the sample stage 108. Then, the sample 106 is placed on the sample table 108 without being electrostatically attracted. In this state, the contact between the sample 106 and the sample stage 108 is slight, and the sample 106 is moved from the sample 106 to the sample stage 108 or to the sample stage 108.
Transfer of heat from the sample to the sample 106 is suppressed. Then, plasma was generated under discharge conditions of argon gas at 100 ml / min, pressure of 1 Pa, and microwave power of 500 w to obtain a sample 106.
Is heated to 150 ° C. FIG. 3 shows the sample 106 at this time.
3 shows the temperature change.

After that, the sample was heated under the condition that the sample was heated using chlorine and oxygen described in the first embodiment as an etching gas.
Process up to the state of (b). After that, a DC voltage is applied by the DC power supply 113 to electrostatically attract the sample 106 to the sample table 108. In this state, the sample 106 and the sample stage 10
8 and the heat transfer becomes good. Then, the sample 106 was cooled to 20 ° C., and hydrogen bromide and oxygen described in Example 1 were used as an etching gas in FIG.
Process up to the state of (c).

FIG. 5B is a diagram showing an example of the relationship between the side etch amount of the polycrystalline silicon film and the sample temperature. As shown in FIG. 5B, when the sample temperature exceeds about 30 ° C., the amount of side etching tends to increase as the sample temperature increases. Therefore, in etching the polycrystalline silicon film, it is desirable to lower the sample temperature in order to avoid side etching.

FIG. 6 shows an example in which the dependence of the processed shape on the sample temperature when a polycrystalline silicon film is formed using hydrogen bromide and oxygen as an etching gas. FIG. 6A shows an example of etching a polycrystalline silicon film at a sample temperature of 20 ° C. as an example of the present invention. 6B and 6C show, as comparative examples, cases where the sample temperature is 80 ° C. and 150 ° C.

As in this embodiment, the tungsten film is processed at a high temperature, for example, 100 ° C. to 200 ° C., and the polycrystalline silicon film is processed at a low temperature, for example, a temperature range of 0 ° C. to 80 ° C. There is no partial etching residue of the film or the tungsten nitride film, and excellent processing accuracy without side etching of the polycrystalline silicon film can be obtained.

Third Embodiment Next, a third embodiment will be described. FIG. 4 shows an apparatus including a plurality of plasma processing chambers to which the present invention is applied. This apparatus is equipped with a sample loading chamber 30.
1. Buffer chamber 305 that has been evacuated, transfer robot 302 for transferring the sample to each processing chamber, and A processing chamber 303 and B processing chamber having the same configuration as FIG. 304. The sample to be processed is transferred to the A processing chamber 3 by the transfer robot 302 via the loading chamber 301.
03, placed on the sample stage 108 heated to 150 ° C., and electrostatically attracted to quickly raise the sample temperature to 1
The temperature was raised to 50 ° C., and the treatment was performed up to the state shown in FIG. 2B under the conditions using chlorine and oxygen as the etching gas described in the first embodiment. Thereafter, the sample to be processed is carried into the B processing chamber 304 by the transfer robot 302, placed on the sample stage 108 cooled to 10 ° C., and rapidly cooled to 20 ° C. by electrostatic attraction, and FIG. 2C shows a condition where hydrogen bromide and oxygen described in Example 1 were used as an etching gas.
Process up to state.

As in this embodiment, the tungsten film and the polycrystalline silicon film are successively processed in a processing chamber having a sample stage controlled at different temperatures, so that the tungsten film or the tungsten nitride film is partially etched. And excellent processing without side etching on the polycrystalline silicon film can be efficiently performed.

(Embodiment 4) As Embodiment 4, an application example in which a high-frequency power source is turned on and off from continuous application to application will be described. First, a description of the on / off operation of the high frequency power supply will be described below.

FIG. 7 shows the vacuum vessel 11 during the etching process.
0 gas supply, magnetron 101, high frequency power supply 11
2 shows the operation of the rf bias applied by No. 2. Gas is supplied as shown in FIG.
The gas pressure is kept constant, and microwaves are also continuously supplied as shown in (b). On the other hand, as shown in (c), the rf bias applied to the sample is periodically turned on and off. By providing a period during which ions are accelerated by turning on and off the rf bias, a high energy ion section and a low energy ion section are generated during the surface treatment of the sample. Then, as shown in (d), in the low-energy ion section, the etching does not proceed, but rather a deposition of a gas or a residual reaction product in the plasma occurs.

Next, the relationship between the frequency of the rf bias, its on / off repetition frequency, and the etching characteristics will be described. FIG. 8 shows the waveform of the rf bias. FIG. 8A shows the waveform when the frequency of the rf bias is 100 kHz and the on / off frequency (modulation frequency) is 100 Hz. (b) is Japanese published patent publication No. 6-151360 (corresponding USP)
5,352,324).
This is a waveform when the rf bias frequency is 1 kHz and the on / off frequency (modulation frequency) is 1 Hz.

Next, a specific embodiment using the plasma etching apparatus shown in FIGS. 1 and 3 will be described. A processing room 3
At 03, the refrigerant temperature controller 111
The sample 106 is placed on the sample stage 108 whose temperature is controlled to 0 ° C.
Heat to ° C. The process is performed up to the state shown in FIG. 2B under the conditions described in Example 1 using chlorine and oxygen as etching gases. At this time, the high frequency power is turned on and off, and the high frequency power is 500
W, the on / off frequency (modulation frequency) is 1 kHz, and the ratio of the on period to one on / off cycle is 30%. Thereafter, the sample is transferred to the B processing chamber 304 by the transfer robot 302, placed on the sample stage 108 cooled to 5 ° C., and quickly cooled to 5 ° C. by electrostatic attraction to rapidly cool the sample temperature to 5 ° C. 2 (c) under the condition of using hydrogen bromide and oxygen as an etching gas.

By turning on / off the high-frequency power supply during the etching of the tungsten film as in this embodiment, a higher rf bias than before can be applied to the tungsten film, and the tungsten film and the barrier film are processed without partial etching residue. In addition, the difference in etching rate between a dense part and a relatively sparse part of the pattern is reduced, so that microscopic charge-up damage can be reduced.

[0033]

As described above, according to the present invention, in etching a multi-layer film including a metal film and a polycrystalline silicon film, the metal film is processed at a high temperature of 100 ° C. to 200 ° C. when etching the metal film. By doing so, the etching rate of the metal film is increased, so that there is no partial etching residue of the metal film and the barrier film, and when the etching of the barrier film is completed, the polycrystalline silicon film is selected with respect to the oxide film with high selectivity. High-precision processing can be performed by switching to etching conditions. Further, by turning on / off the high-frequency power supply at the time of etching, microscopic charge-up damage can be reduced.

[Brief description of the drawings]

FIG. 1A is a diagram showing a configuration of a plasma etching processing chamber according to an embodiment of the present invention.

FIG. 1B is a diagram showing a detailed structure of a sample stage portion of FIG. 1A.

FIG. 2 is a diagram showing a change in an etching state in a cross-sectional view of a sample.

FIG. 3 is a diagram showing a temporal change in the sample temperature when the sample temperature is raised using plasma.

FIG. 4 is an overall configuration diagram of an apparatus including a plurality of plasma processing chambers to which the present invention is applied.

FIG. 5A is an example in which the sample temperature dependence of the etching rate of a tungsten film, a polycrystalline silicon film, and an oxide film is examined using chlorine and oxygen as etching gases.

FIG. 5B is a diagram showing an example of a relationship between a side etch amount of a polycrystalline silicon film and a sample temperature.

FIG. 6 is an example of examining the sample temperature dependence of a processed shape when hydrogen bromide and oxygen are used as an etching gas in a polycrystalline silicon film.

FIG. 7 is a view showing operations of gas supply, a magnetron, and an rf bias power supply in a vacuum vessel when etching is performed by turning on / off a high-frequency power supply in the apparatus of FIG. 1A.

FIG. 8 is an explanatory diagram of an rf bias waveform in the case of FIG. 7;

[Explanation of symbols]

101-microwave power supply, 102-waveguide, 103-quartz plate, 104-electromagnet 105-plasma, 106-sample, 107-temperature sensor, 108-sample stage, 109-dielectric film, 110-vacuum vessel, 111- Refrigerant temperature controller, 112-high frequency power supply, 113-DC power supply, 114-valve, 115-shaft,
116-insulating film, 117-coolant introduction nozzle, 118-insulating plate, 119-susceptor, 120-piping, 121-intermediate electrode member, 122-lower electrode member, 123-void, 1
24-gap, 125-upper electrode member, 201, 601
Mask, 202, 602-tungsten film, 203,
603-tungsten nitride film, 204, 604-polycrystalline silicon film, 205-oxide film, 206-silicon substrate,
301-loading room, 302-transport robot, 303-A processing room, 304-B processing room, 305-buffer room, 605
−Side etch

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] October 29, 1999 (1999.10.
29)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Brief description of drawings

[Correction method] Change

[Correction contents]

[Brief description of the drawings]

FIG. 1A is a diagram showing a configuration of a plasma etching processing chamber according to an embodiment of the present invention.

FIG. 1B is a diagram showing a detailed structure of a sample stage portion of FIG. 1A.

FIG. 2A is a sectional view of a sample showing an initial state of etching.

FIG. 2B is a cross-sectional view of a sample showing a change in an etching state.
FIG.

FIG. 2C is a cross-sectional view of a sample showing a change in an etching state.
FIG.

FIG. 3 is a diagram showing a temporal change in the sample temperature when the sample temperature is raised using plasma.

FIG. 4 is an overall configuration diagram of an apparatus including a plurality of plasma processing chambers to which the present invention is applied.

FIG. 5A is an example in which the sample temperature dependence of the etching rate of a tungsten film, a polycrystalline silicon film, and an oxide film is examined using chlorine and oxygen as etching gases.

FIG. 5B is a diagram showing an example of a relationship between a side etch amount of a polycrystalline silicon film and a sample temperature.

FIG. 6A is a diagram showing a sample temperature dependency of a processed shape according to a method of an embodiment of the present invention when a polycrystalline silicon film uses hydrogen bromide and oxygen as an etching gas .

FIG. 6B: Etch hydrogen bromide and oxygen to a polycrystalline silicon film
In the case of using a machining gas,
It is a figure which shows a sample temperature dependency.

FIG. 6C shows etching of polycrystalline silicon film with hydrogen bromide and oxygen
In the case of using a machining gas,
It is a figure which shows a sample temperature dependency.

FIG. 7 is a view showing operations of gas supply, a magnetron, and an rf bias power supply in a vacuum vessel when etching is performed by turning on / off a high-frequency power supply in the apparatus of FIG. 1A.

FIG. 8 is an explanatory diagram of an rf bias waveform in the case of FIG. 7;

[Description of Signs] 101-microwave power supply, 102-waveguide, 103-quartz plate, 104-electromagnet 105-plasma, 106-sample, 107-temperature sensor, 108-sample stage, 109-dielectric film, 110- Vacuum vessel, 111-refrigerant temperature controller, 112-high frequency power supply, 113-DC power supply, 114-valve, 115-axis,
116-insulating film, 117-coolant introduction nozzle, 118-insulating plate, 119-susceptor, 120-piping, 121-intermediate electrode member, 122-lower electrode member, 123-void, 1
24-gap, 125-upper electrode member, 201, 601
Mask, 202, 602-tungsten film, 203,
603-tungsten nitride film, 204, 604-polycrystalline silicon film, 205-oxide film, 206-silicon substrate,
301-loading room, 302-transport robot, 303-A processing room, 304-B processing room, 305-buffer room, 605
−Side etch

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takao Arase 794, Higashi-Toyoi, Katsumatsu-shi, Kudamatsu-shi, Yamaguchi Pref.Hitachi Techno Engineering Co., Ltd. Address Kasado Works, Hitachi, Ltd. (72) Inventor, Tetsuro Ono 794, Higashi-Toyoi, Kazamatsu-shi, Yamaguchi Prefecture, Japan Kasado Works, Hitachi, Ltd. (72) Inventor Naofumi Tokunaga 6-16, Shinmachi, Ome-shi, Tokyo No. 2 Inside Hitachi Device Co., Ltd. Device Development Center (72) Inventor Tadafumi Umezawa 6-16 Shinmachi, Ome-shi, Tokyo Inside 2 Co., Ltd. Hitachi Ltd. Device Development Center (72) Inventor Masayuki Kojima Josui, Kodaira-shi, Tokyo 5-20-1, Honmachi Within the Semiconductor Group, Hitachi, Ltd. (72) Inventor Kazuo Nojiri 6-16-16 Shinmachi, Ome-shi, Kyoto Inside the Hitachi, Ltd. Device Development Center Co., Ltd. (72) Inventor Dr. Kawakami 6-16-16 Shinmachi, Ome-shi, Tokyo 2 F-term in the Hitachi, Ltd. Device Development Center (reference) 4M104 BB01 CC05 DD65 FF18 GG09 GG10 GG14 HH20 5F004 AA01 BA14 BB22 BB25 BB26 BC06 BD03 CA02 CA04 DA00 DA04 DA22 DA23 DA26 DB02 DB10 EB04 FA01 5F033 HH04 HH19 HH32 QQ08 QQ10 QQ12 QQ15 WW10 XX03

Claims (14)

[Claims] 1. A vacuum vessel, means for generating plasma in the vacuum vessel, a sample stage on which a sample whose surface is to be processed by the plasma is installed, a temperature control mechanism for controlling the temperature of the sample stage, and
Using a surface processing apparatus including a power supply for applying a high-frequency voltage to the sample stage, a surface processing method for processing a sample formed of a multilayer film including at least a metal film and a semiconductor film deposited on a semiconductor substrate, A surface processing method characterized by maintaining a sample temperature at 70 ° C. or more and 200 ° C. or less during metal film processing. 2. The method according to claim 1, wherein the gas for generating the plasma is a mixed gas of a gas containing at least a halogen atom and a gas containing an oxygen atom. 3. The method according to claim 1, wherein the processed multilayer film includes at least a tungsten film and a polycrystalline silicon film. 4. The method according to claim 3, wherein a tungsten nitride film or a titanium nitride film is included between the tungsten film and the polycrystalline silicon film. 5. The method according to claim 1, wherein the step of processing the multilayer film is divided into a plurality of steps. 6. The method according to claim 5, wherein the semiconductor film is processed in a temperature range of 0 ° C. to 80 ° C. 7. The surface processing apparatus uses an apparatus composed of a plurality of vacuum vessels for surface processing, and separates a vacuum vessel for performing surface processing on the metal film and a vacuum vessel for performing surface processing on the semiconductor film. The method for processing a surface of a sample according to claim 1, wherein: 8. The surface processing apparatus according to claim 1, wherein the surface processing apparatus performs the surface processing on both the metal film and the semiconductor film by using an apparatus including one vacuum chamber for surface processing. Surface processing method of the sample. 9. The method according to claim 1, wherein a plasma is generated by a gas containing at least an inert gas such as an argon gas or a helium gas before performing the surface processing with the mixed gas, and the sample temperature is raised. 2. The method for processing a surface of a sample according to 2. 10. The method according to claim 2, wherein the pressure of the mixed gas is 1.0 Pa (Pascal) or less. 11. The method according to claim 1, wherein the sample is held on the sample table by electrostatic attraction. 12. The surface processing method according to claim 1, wherein the high-frequency voltage applied to the sample stage is periodically turned on and off to perform plasma processing. 13. The surface processing method according to claim 12, wherein
The repetition frequency for turning on and off the high frequency voltage is 10
A surface processing method wherein the frequency is in the range of 0 Hz to 10 kHz. 14. The surface processing method according to claim 12, wherein a ratio of one cycle of turning on and off the high-frequency voltage is in a range of 5% to 60%.