JP2000235972A - Plasma processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To heat a chamber by bonding a light-absorbing layer to the dielectric part of the chamber so as to absorb light energy of a heat lamp with the light- absorbing layer. SOLUTION: A pair of annular antennas 34 are provided around a source chamber 24 made of quartz glass, and they are surrounded by a cover 36 made of quartz glass. A light-absorbing layer is bonded to the surface on the atmosphere side of the source chamber 24, so that infrared rays from an infrared lamp 44 are absorbed by the light-absorbing layer and the source chamber 24 is heated to 200 deg.C. When a magnetic field is generated by a magnetic field generating coil 46, while a helicon wave excitation electrical field is applied to the antenna 34, a helicon wave plasma is generated in the source chamber 24. When a silicon oxide film is etched using fluorocarbon gas, accumulation on the inner wall surface of the heated source 24 is eliminated, so that microparticles in plasma caused by peeling-off of accumulated film is decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing apparatus for etching or depositing a semiconductor element or the like using plasma, and more particularly, to generating plasma inside a dielectric chamber using an external antenna. The present invention relates to a plasma processing apparatus in which a chamber is heated by a heating lamp.

[0002]

2. Description of the Related Art FIG. 9 is a front sectional view showing an example of a conventional plasma processing apparatus. This plasma processing apparatus includes a helicon wave plasma source. A pair of annular antennas 12 are arranged around a quartz source chamber 10, and a pair of magnetic field generating coils 14 are arranged so as to surround them. When a current is applied to the coil 14 to generate an external magnetic field and a helicon wave excitation electric field is applied to the antenna 12, a helicon wave plasma is generated inside the source chamber 10. The plasma is diffused into the diffusion chamber 16 and the wafer 20 to be processed on the substrate holder 18 is diffused.
Is etched. If a bias voltage is applied to the substrate holder 18 using the high frequency power supply 22 for bias, the energy of ions incident on the wafer 20 can be suppressed.

[0003] The helicon wave plasma source described above is characterized in that high-density plasma can be generated at a low pressure. When a high-density plasma is generated under low pressure, the density of neutral dissociated radicals also increases. Further, since the electron temperature increases, the radical species also have a higher degree of dissociation. For example, a case in which a silicon oxide film is etched using a fluorocarbon gas plasma will be described. In a low-pressure, high-density plasma, the density of CF, which is a radical of high dissociation degree, is
It increases relatively to CF ₃ which is a low dissociation degree radical. Fluorocarbon gas generally has a larger adhesion rate as the degree of dissociation advances. For example, C
The adhesion probabilities of the F radical and the CF ₃ radical with respect to Si are 0.14 and 0.0, respectively. Incidentally, the attachment probability of C atom, which is the final dissociation radical, to Si is 1.
Very large, 0.

[0004]

As described above, at least in the etching of a silicon oxide film with a fluorocarbon gas, the incident amount of dissociated radicals increases as the pressure and density of plasma increase, and the species of generated radical species increases. Although the probability of adhesion increases, there is also a problem that the growth of the deposited film proceeds on the inner wall surface of the chamber. When the growth rate of the deposited film increases on the inner wall surface of the chamber, the deposited film tends to peel off from the wall surface, and the number of microparticles floating in the plasma increases. When the fine particles fall on the substrate, the fine particles serve as a mask, which hinders the etching of the substrate, and causes defects such as an abnormal etching shape and a short circuit. As a result, there arises a problem that the yield of semiconductor devices and the like is reduced.

[0005] In a conventional etching apparatus provided with a helicon wave plasma source, deposition on the wall surface of a source chamber (a chamber for generating plasma) is particularly remarkable. I didn't. For this reason, a large amount of particles are generated, which has been a major problem when applied to a semiconductor element production site. Further, since most of the deposited radicals, which have an important effect on increasing the selectivity of the film to be etched with respect to the underlying Si, adhere to the chamber walls, the underlying S
There has been a problem that the amount of radicals deposited on i decreases, and as a result, a sufficient selectivity with respect to the base cannot be obtained.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to make it possible to efficiently heat a chamber, suppress the deposition of a film on the chamber wall, and reduce the amount of floating particles. An object of the present invention is to provide a plasma processing apparatus with a small number.

[0007]

SUMMARY OF THE INVENTION The present invention provides a plasma processing apparatus of the type in which an antenna is disposed outside a dielectric portion of a chamber to generate plasma, wherein a light absorbing layer is formed in close contact with the dielectric portion of the chamber. The chamber is heated by absorbing the light energy of the heating lamp into the light absorbing layer. Thus, even if the material of the dielectric portion constituting the chamber is inferior in light absorbency, the dielectric portion can be efficiently heated. Therefore, a material (for example, quartz glass) which is inferior in light absorbency but excellent in other respects can be used as a material for the dielectric portion of the chamber.

The light absorbing layer preferably has a higher thermal conductivity than the material of the dielectric portion. Thereby, the temperature distribution of the dielectric when heating the dielectric portion of the chamber becomes uniform.

When quartz is used for the dielectric portion, the light absorbing layer may be made of, for example, AlN, BN, or Si.
₃ N _4, SiC, can be used Al ₂ O _3. Further, a substance having a better light absorbing property, for example, fine particles such as CrO ₂ , SiC, and carbon black may be mixed into the light absorbing layer. Further, by making the light absorbing layer porous, the light absorbing property can be improved.

Further, it is preferable that the dielectric portion and the antenna are surrounded by a light-reflective cover so that the light energy of the heating lamp does not leak outside.

The plasma processing apparatus of the present invention can be applied to any plasma processing in which some effect can be expected by heating the inner wall surface of the chamber. For example, when a silicon oxide film is etched using a fluorocarbon gas, by heating the inner wall surface of the chamber to about 200 ° C., it becomes difficult to form a deposited film on the inner wall surface of the chamber. This can prevent the generation of minute particles. In addition to such processing examples, A
It is also effective when the volatility of the reaction product is low, such as etching of l or etching of polysilicon with a chlorine-based gas. In addition to the etching process, the present invention is also effective for surface treatment using plasma or film formation using plasma CVD.

[0012]

FIG. 1 is a front sectional view of a first embodiment of the present invention. This plasma processing apparatus is an etching apparatus provided with a helicon wave plasma source. The chamber that can be evacuated includes a source chamber 24 and a diffusion chamber 26. The diffusion chamber 26 has an exhaust system 2
8 and the gas introduction mechanism 30 are connected. Inside the diffusion chamber 26, there is a substrate holder 32 for mounting the wafer 31 to be processed. A high frequency bias power supply 33 is connected to the substrate holder 32, and by generating a bias voltage on the wafer 31, the energy of ions incident on the wafer 31 can be suppressed.

Around the diffusion chamber 26, a plurality of permanent magnets whose poles are alternately changed (bar-shaped permanent magnets whose pole faces face the diffusion chamber and extend vertically) are arranged at equal intervals. The cusp magnetic field may be formed near the inner wall surface of the diffusion chamber 26 by disposing the cusp magnetic field. In this case,
The plasma is less likely to touch the inner wall of the diffusion chamber,
Plasma loss can be suppressed.

A pair of annular antennas 34 are arranged around the dielectric source chamber 24. And
A cover 36 is arranged so as to surround the source chamber 24 and the antenna 34. The cover 36 includes a cylindrical body 38 made of quartz (transparent glass) and a circular plate 40 made of quartz (transparent glass). A black electrically insulating annular body 42 is provided between the upper end of the cylindrical body 38 and the plate 40.
Is arranged. An infrared lamp (halogen lamp) 44 as a heating lamp is disposed above the source chamber 24 inside the cover 36. A pair of magnetic field generating coils 46 are arranged around the cylindrical body 38. When a current is applied to the magnetic field generating coil 46 to generate an external magnetic field and a helicon wave excitation electric field is applied to the antenna 34, a helicon wave plasma is generated inside the source chamber 24.

FIG. 2 is a sectional view taken along line AA of FIG. An antenna 34, a cylindrical body 38, and a pair of magnetic field generating coils 46 are concentrically arranged around the central source chamber 24 in this order from the inside. One end of the antenna 34 is connected to a high frequency power source 54 for plasma generation via a matching box 52. The other end of the antenna 34 is grounded.

As the main material of the source chamber 24 made of a dielectric material, quartz having excellent characteristics from the viewpoint of thermal strain, thermal shock and the like was employed. However, difficulties in employing quartz as the main material of the chamber are that it cannot be efficiently heated because the light energy absorption rate is not high and that the thermal conductivity is low (0.003 cal / cm · sec · ° C.). Another problem is that the entire chamber cannot be heated uniformly. Explaining the former point, a halogen lamp has a peak of emission intensity around a wavelength of 1 μm, while quartz has a transmittance of 90% or more for a light beam of a wavelength of 2 μm or less. Therefore, the light energy of the halogen lamp is hardly absorbed by the source chamber. Therefore, in the present invention, as shown in an enlarged manner in FIG. 5, the light absorbing layer 50 is formed in close contact with the surface of the quartz glass 48 constituting the source chamber on the atmosphere side. As a material of the light absorbing layer 50, an electric insulating material having a higher light absorption rate than quartz and having a higher thermal conductivity than quartz, for example, Al
N, BN, Si ₃ N ₄ , SiC, and Al ₂ O ₃ are used.
In order to generate plasma by an inductive coupling method using an antenna, the material of the light absorbing layer must be an electrically insulating material as in the case of the source chamber. The thermal conductivity and color (related to infrared absorptivity) of these materials, along with quartz, are shown in Table 1 below.

[0017]

[Table 1] Material Thermal conductivity [cal / cm · sec · ° C] Color AlN 0.36 White BN 0.2 White Si ₃ N ₄ 0.07 Black gray SiC 0.20 Black Al ₂ O ₃ 0.05 White Quartz 0.003 transparent

In addition, fine particles such as CrO ₂ , SiC, and carbon black, which have better light absorbing properties, can be mixed into the light absorbing layer 50 to increase the absorptivity of infrared rays. Further, by making the light absorbing layer 50 porous, the efficiency of absorbing infrared rays can be further increased. By making it porous, the infrared rays incident on the light absorbing layer 50 are
The reflection is repeated in the porous pores, and as a result, the light absorption efficiency is increased.

Next, the light reflection film of the cover will be described. FIG.
4 and FIG. 4, a light reflecting film is formed on the cylindrical body 38 and the plate 40 constituting the cover. FIG. 3 (A)
Is a front view of the plate 40, and shows the formation positions of the light reflection film on the upper and lower surfaces thereof. FIG. 3 (B)
Is a plan view of the cylindrical body 38, and shows the formation positions of the light reflection film on the inner peripheral surface and the outer peripheral surface thereof. FIG. 4 shows the cylindrical body 3
FIG. 8 is a perspective view of the light reflection film 8 and a plate 40, similarly showing positions where light reflection films are formed.

First, the light reflecting film of the cylindrical body 38 will be described.
In FIG. 3B, five reflective films 56 are formed on the inner peripheral surface of the cylindrical body 38 at regular intervals in the circumferential direction. The reflection film 56 is, as shown in FIG.
8 in the axial direction. On the other hand, five reflective films 58 are also formed on the outer peripheral surface of the cylindrical body 38 at equal intervals in the circumferential direction. The inner reflective film 56 and the outer reflective film 58 are arranged so that their circumferential positions partially overlap. That is, at the circumferential region 60 in FIG. 3B, the inner reflective film 56 and the outer reflective film 5
8 are present. Due to the existence of such an overlapping region, infrared rays coming from an arbitrary position in the source chamber 24 are always reflected by one of the inner reflective film 56 and the outer reflective film 58 of the cylindrical body 38. To explain this geometrically, assuming a straight line 62 passing through an arbitrary position of the source chamber 24 and an arbitrary position of the cylindrical body 38, the straight line 62 is at least the inner reflective film 56 and the outer reflective film 58. Pass through either.

After all, the reflection films 56 and 58 reflect the infrared rays coming from the source chamber 24 and do not allow the infrared rays to escape to the outside of the cylindrical body 38, so that most of the light energy generated by the heating lamp is reduced. Finally, the light is absorbed by the light reflecting film of the source chamber 24. In addition, since infrared rays do not escape from the cylindrical body 38 to the outside, there is no danger of heating electronic devices and the like arranged outside.

By the way, a substance which easily reflects infrared rays is often conductive, but if a conductive reflective film is formed continuously in the circumferential direction, an annular closed electric circuit can be formed. Then, the following inconvenience occurs. In FIG. 1, when a high-frequency electric field is applied to the antenna 34, a magnetic field which fluctuates in the axial direction of the source chamber 24 is generated. If there is an electric circuit closed in the circumferential direction on the surface of the cylindrical body 38, an annular induction electric field is formed in the electric circuit by the above-described axially fluctuating magnetic field, and a large current flows through the electric circuit (reflection film). Will flow. This current does not contribute to the generation of plasma, but results in a loss of energy. In addition, when a current flows through the reflective film, Joule heat is generated, which may cause peeling of the reflective film and shorten the life of the reflective film. For this reason, the reflection films 56 and 58 are not closed in the circumferential direction, and the infrared rays are not leaked to the outside.
It has a special arrangement as shown in Figure 2.

When the reflection film is conductive,
As shown in (B), the inner reflective film 56 and the outer reflective film 58
Accordingly, as a whole, the antenna is surrounded by the conductive film, and there is also an effect of preventing the electromagnetic power generated from the antenna from leaking out of the cylindrical body 38.

Next, the light reflection film of the plate 40 will be described. 3 (A) and FIG. 4, four reflective films 64 are formed on the upper surface of the plate 40 at regular intervals so as to be parallel to each other. On the other hand, on the lower surface of the plate 40, three reflective films 66 are formed at regular intervals so as to be parallel to each other. The relative positional relationship between the upper reflective film 64 and the lower reflective film 66 is the same as the relative positional relationship between the reflective films 56 and 58 in the cylindrical body 38.
That is, the reflection film 64 on the upper surface and the reflection film 66 on the lower surface partially overlap, and infrared rays coming from the source chamber are always reflected by one of the reflection films 64 and 66.

As shown in FIG. 4, between the upper end of the cylindrical body 38 and the lower surface of the plate 40, a black electrically insulating annular body 42 is sandwiched. By making the annular body 42 black, infrared rays are prevented from leaking outside through the annular body 42. Further, by making the annular body 42 electrically insulating, any one of the reflecting films 56 and 58 of the cylindrical body 38 and one of the reflecting films 64 and 66 of the plate 40 conduct, and an electric circuit closed in the circumferential direction is not formed. It is prevented from being formed easily.

Next, using the plasma processing apparatus of FIG.
A method for etching a silicon oxide film will be described. First, in FIG. 1, the wafer 31 to be processed is placed on the substrate holder 32. The processing target wafer 31 is obtained by applying a photoresist on a silicon oxide film and subjecting the photoresist to a desired patterning. next,
The helicon wave plasma source is operated in the following procedure. First, the source chamber 24 and the diffusion chamber 26 are evacuated by the exhaust system 28. Next, the infrared lamp 44 is turned on to confirm that the surface of the source chamber 24 is heated to 200 ° C. or more by a temperature measuring means such as a thermocouple (not shown). Then, after the surface temperature of the source chamber 24 reaches 200 ° C., the infrared lamp 44 is turned off when the temperature reaches 205 ° C. or higher, and the infrared lamp 44 is turned on when the surface temperature falls below 200 ° C. Is kept in the range of 200-205 ° C. Such temperature control of the source chamber 24 is automatically performed by the control device. Next, CHF ₃ , C ₂ F ₆ ,
The flow rate of a fluorocarbon gas such as C ₄ F ₈ is controlled by the mass flow controller 29 and supplied to the diffusion chamber 26.
Then, the variable orifice 27 of the exhaust system 28 is controlled to increase the pressure of the chambers 24 and 26 by 1 to 100 Torr.
Control within the range. Next, a magnetic field is generated by the magnetic field generating coil 46, and source power is supplied to the pair of antennas 34 from the plasma generating high frequency power supply 54 shown in FIG. At the same time, a required bias power is supplied to the substrate holder 32 of FIG. 1 from a high frequency bias power supply 33 in order to control the incident energy of ions. When plasma is generated in the source chamber 24 by such a procedure, active species generated by the plasma diffuse into the diffusion chamber 26, and the silicon oxide film on the processing target wafer 31 is etched.

In such an etching process, the plasma processing apparatus has the following function for heating the source chamber. First, since the light absorption layer 50 having a high light absorption rate and a high thermal conductivity is provided on the surface of the quartz source chamber 24 on the atmosphere side,
While the light of the infrared lamp 44 is efficiently absorbed,
The light energy spreads evenly on the surface of the source chamber. Thereby, the inner surface of the source chamber in contact with the plasma can be efficiently and uniformly heated. Second,
Since the cover 36 composed of the cylindrical body 38 and the plate 40 is arranged so as to surround the source chamber 24, and a reflective film is formed on the cover, the light energy reflected or emitted by the source chamber is reflected by the reflective film of the cover. Do not run outside the cover. This light energy is
Since the light is finally absorbed by the light absorbing layer of the source chamber, the source chamber can be efficiently heated.

The heating temperature of the source chamber is about 200 ° C.
By doing so, there is no deposition on the inner wall surface of the source chamber when the silicon oxide film is etched using the fluorocarbon gas. As a result, the number of particles on the wafer is remarkably reduced, and radicals adhere to the wafer, so that the selectivity with respect to the underlying Si is improved.

FIG. 6 is a front sectional view of a second embodiment of the present invention. In this embodiment, the top plate 70 of the chamber 68 is a dielectric part. A spoke-shaped antenna assembly 72 is disposed above the upper surface plate 70. Then, UHF is attached to this antenna assembly 72.
By supplying alternating power from the power source 74, the chamber 68
Plasma is generated inside. A plasma generation system including a combination of such a spoke-shaped antenna assembly 72 and a UHF power supply 74 is disclosed in Japanese J.
ournal of Applied Physics, Vol.34 (1995) pp.6805-6
808.

FIG. 7 is a sectional view taken along line BB of FIG. The antenna assembly 72 includes a plurality of outer antennas 76 arranged in a spoke shape (radial shape) and a plurality of inner antennas 78 arranged in a spoke shape. One end of the outer antenna 76 is fixed to the cover 90. The cover 90 is grounded. One end of the inner antenna 78 is fixed to a column 79. The support 79 is also grounded. Then, the two outer antennas 76a and 76b facing each other
Alternating power of a short wavelength in the UHF band (or VHF band) is supplied from an HF power supply (may be a VHF power supply).
Above the antenna assembly 72, an annular infrared lamp 80 (see also FIG. 6) is arranged. Returning to FIG. 6, the antenna assembly 72 is for coupling the power from the UHF power supply 74 to the plasma, and the stub 82 is for adjusting the degree of coupling between the plasma and the antenna.

The circular upper plate 70 has an upper quartz glass plate 84.
And a lower quartz glass plate 86. Lower quartz glass plate 8
6 is as thin as 2-3 mm. Then, the total thickness of the upper surface plate 70 is set to be strong enough to withstand the pressure difference between the atmospheric pressure and the vacuum. For example, when a 12-inch wafer is assumed as the substrate to be processed, the upper plate 7
The diameter of 0 is about 400 mm, and the thickness of the top plate 70 needs to be about 25 mm. Therefore, the thickness of the upper quartz glass plate 84 in this case is 22 to 23 mm. On the upper surface of the lower quartz glass plate 86, a light absorbing layer 88 is formed in close contact. The material of the light absorbing layer 88 is the same as that of the light absorbing layer 50 of FIG. That is, AlN, BN, Si
₃ N _4, SiC, a material such as Al ₂ O _3, to,
Fine particles such as CrO ₂ , SiC, and carbon black may be mixed.

The space above the upper plate 70 is a cylindrical cover 9.
The antenna assembly 72 and the heating lamp 80 are disposed inside the cover 90.
The cover 90 is made of a metal (conductor) such as aluminum, and its inner surface is finished to have a high light reflectance. The plasma generation system according to this embodiment includes:
Unlike the embodiment of FIG. 1, there is no circumferential annular electric field because the antenna does not generate an axial magnetic field. Therefore, there is no problem even if a current circuit closed in the circumferential direction in the cover 90 occurs. Therefore, there is no problem even if the entire cover 90 is made of a conductor.

Also in the second embodiment, infrared rays from the infrared lamp 80 are absorbed by the light absorbing layer 88, and the lower quartz glass plate 86 is efficiently heated. Since the infrared rays are reflected by the reflection surface on the inner surface of the cover 90, the light energy does not leak to the outside of the cover 90, so that the lower quartz glass plate 86 is efficiently heated.

If the upper plate 70 is formed of a single quartz glass plate, the following problem arises. In order to cope with a large-diameter wafer, the diameter of the top plate becomes large, and in order to withstand the pressure difference between atmospheric pressure and vacuum, it is necessary to make the quartz glass plate thick. For example, to accommodate a wafer having a diameter of 12 inches, the thickness of the quartz glass plate needs to be 25 mm or more as described above. When a light absorbing layer is formed in close contact with the upper surface of the quartz glass plate, the distance (equal to the thickness of the quartz glass plate) from the light absorbing layer to the lower surface of the quartz glass plate increases. Therefore, even if the light absorption layer is heated, the temperature decreases on the lower surface (the surface in contact with plasma) of the quartz glass plate due to the temperature gradient in the thickness direction of the quartz glass plate. Therefore, as shown in FIG. 6, by providing a light absorbing layer 88 on the upper surface of the thin lower quartz glass plate 86, the lower surface of the lower quartz glass plate 86 is prevented from lowering in temperature and the temperature distribution on the lower surface is made uniform. I have to.

The procedure for etching a silicon oxide film using the plasma processing apparatus of the second embodiment is almost the same as that of the embodiment of FIG. The difference is UHF
Alternatively, in order to supply short-wavelength power in the VHF band with an antenna, matching matching uses a stub tuner instead of a matching box.

FIG. 8 is a front sectional view of a third embodiment of the present invention. This embodiment is almost the same as the embodiment of FIG. 6, except for the structure of the top plate of the chamber. The upper surface plate 92 is composed of a first quartz glass plate 94 constituting a top plate of the chamber, and a second quartz glass plate 96 arranged below the first quartz glass plate 94 at intervals. The second quartz glass plate 96 is supported by a support member 100 such as a hook, and the first quartz glass plate 9
No contact with 4. The first quartz glass plate 94 is for maintaining a vacuum and is relatively thick. On the other hand, the second quartz glass plate 96 does not need to withstand the atmospheric pressure and can be made thin, and the light absorbing layer 98 is formed on the upper surface thereof in close contact. The material of the light absorbing layer 98 is the same as that of the light absorbing layer 50 of FIG. The second quartz glass plate 96 is disposed inside the chamber, and has a light absorbing layer 9 on its upper surface.
Numeral 8 is on the side opposite to the surface (lower surface) in contact with the plasma. The infrared light from the infrared lamp 80 is supplied to the first quartz glass plate 94.
And is absorbed by the light absorbing layer 98 of the second quartz glass plate 96, and the second quartz glass plate 96 is heated. Since the quartz glass plate 94 is thin, it has a small heat capacity and the first
Because it is not in contact with the quartz glass plate 94, the temperature rises rapidly.

Instead of using the second quartz glass plate 96 on which the light absorbing layer 98 is formed, a dielectric plate made of the same material as the light absorbing layer 98 may be used. That is, AlN, BN, Si ₃
The dielectric plate is made of N ₄ , SiC, Al ₂ O ₃ or the like. In this case, since the light absorption rate of the dielectric plate itself is good, it is not necessary to form a separate light absorption layer on the surface. If the dielectric plate alone has insufficient light absorption, it is advisable to mix a light absorbing substance such as CrO ₂ , SiC, or carbon black into the dielectric plate.

In each of the first to third embodiments, the light absorbing layer is formed on the side of the quartz glass plate that does not come into contact with the plasma, but the light absorbing layer is formed on the side that comes into contact with the plasma. Even if it is formed, the effect is not so different in terms of heating the quartz glass plate. However, if the light absorbing layer is formed on the side in contact with the plasma, the light absorbing layer is sputtered by the plasma, and this is mixed into the plasma, with the result that there is a possibility that the light absorbing layer will have an adverse effect on the wafer to be processed. Therefore,
The light absorption layer is preferably formed on the side not in contact with the plasma.

[0039]

According to the present invention, the light absorbing layer is formed in close contact with the dielectric portion of the chamber, and the light absorbing layer absorbs the light energy of the heating lamp, thereby heating the chamber. The body part can be efficiently heated. Accordingly, a material (for example, quartz glass) which is inferior in light absorbency but is otherwise excellent can be used as a material for the dielectric portion of the chamber. If a material having good thermal conductivity is selected as the material of the light absorbing layer, the temperature distribution in the dielectric portion of the chamber becomes uniform. in this way,
Since the dielectric portion of the chamber can be efficiently heated, the deposition on the inner wall surface of the chamber is reduced, and the generation of minute particles due to the separation of the deposited film can be prevented.

[Brief description of the drawings]

FIG. 1 is a front sectional view of a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3A is a front view of a plate, and FIG. 3B is a plan view of a cylindrical body.

FIG. 4 is a perspective view of a cylinder and a plate.

FIG. 5 is an enlarged sectional view of a wall surface of a source chamber.

FIG. 6 is a front sectional view of a second embodiment of the present invention.

FIG. 7 is a sectional view taken along the line BB of FIG. 6;

FIG. 8 is a front sectional view of a third embodiment of the present invention.

FIG. 9 is a front sectional view showing an example of a conventional plasma processing apparatus.

[Explanation of symbols]

 Reference Signs List 24 Source chamber 26 Diffusion chamber 31 Target wafer 32 Substrate holder 33 High frequency bias power supply 34 Antenna 36 Cover 38 Cylindrical body 40 Plate 42 Ring body 44 Infrared lamp 46 Magnetic field generating coil 48 Quartz glass 50 Light absorption layer 54 High frequency power supply for plasma generation 56 Inner reflective film 58 Outer reflective film 64 Upper reflective film 66 Lower reflective film

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4K057 DD03 DD10 DE06 DE07 DE08 DG20 DM22 DN01 5F004 AA00 BA20 BB02 BB11 BB18 BB29 BB30 CA09 DA00 DB03 5F045 AA00 AA08 AC02 AF01 AF03 BB14 BB15 DP01 DP02 DP03 DQ10 ECH EC05

Claims (16)

[Claims] 1. A plasma processing apparatus having the following configuration. (A) A vacuum evacuation chamber at least partially made of a dielectric material. (B) An antenna disposed on the atmosphere side of the dielectric portion of the chamber. (C) a power supply for supplying alternating power to the antenna to generate plasma in the chamber. (D) a heating lamp arranged on the atmospheric side of the dielectric portion. (E) a light absorbing layer formed in close contact with the dielectric portion, the light absorbing layer having a higher light absorptivity than a material forming the dielectric portion and being made of an electrically insulating material. (F) An object holder for holding an object to be subjected to plasma processing inside the chamber. 2. The plasma processing apparatus according to claim 1, wherein the light absorption layer is not exposed on a vacuum side of the chamber. 3. The light absorbing layer is formed in close contact with the surface of the dielectric portion on the air side.
The plasma processing apparatus as described in the above. 4. The device according to claim 1, wherein the dielectric portion comprises two dielectric layers on the atmosphere side and on the vacuum side, and the light absorbing layer is formed between the two dielectric layers. 3. The plasma processing apparatus according to 2. 5. The plasma processing apparatus according to claim 1, wherein the light absorbing layer has a higher thermal conductivity than a material forming the dielectric portion. 6. The material of the dielectric portion is quartz, and the light absorbing layer is made of AlN, BN, Si ₃ N ₄ , SiC, Al
_2. The plasma processing apparatus according to claim 1, wherein the apparatus is one of ₂ O ₃ . 7. The plasma processing apparatus according to claim 6, wherein fine particles of any of CrO ₂ , SiC, and carbon black are mixed in the light absorbing layer. 8. The plasma processing apparatus according to claim 1, wherein said light absorbing layer is porous. 9. The plasma processing apparatus according to claim 1, wherein the heating lamp, the dielectric portion, and the antenna are surrounded by a light reflecting surface. 10. The plasma processing apparatus according to claim 1, further comprising: (G) The dielectric portion has a cylindrical shape. (H) A helical or annular antenna is arranged around the dielectric portion. (I) The heating lamp, the dielectric portion, and the antenna are surrounded by a cover composed of an electrically insulating cylinder and an electrically insulating circular plate closing an axial end of the cylinder. . (G) A conductive light reflecting film is formed on the inner surface of the cover so as not to form a conductive circuit closed in the circumferential direction. (F) A conductive light reflecting film is formed on the outer surface of the cover so as not to form a conductive circuit closed in the circumferential direction. (ヲ) Assuming a straight line passing through an arbitrary position of the dielectric portion and an arbitrary position of the cover, the straight line passes through at least one of the light reflecting film on the inner surface and the light reflecting film on the outer surface. As a result, the light reflection film on the inner surface and the light reflection film on the outer surface partially overlap each other. 11. The plasma processing apparatus according to claim 10, wherein an electrically insulating black annular body is disposed between said cylindrical body and said plate. 12. The dielectric part has a flat plate shape, the dielectric part comprises two dielectric layers on the atmosphere side and on the vacuum side, and the light absorption layer is formed between the two dielectric layers. The plasma processing apparatus according to claim 2, wherein the plasma processing apparatus is used. 13. A plasma processing apparatus having the following configuration. (A) A vacuum evacuable chamber at least partially made of a flat external dielectric plate. (B) An antenna arranged on the atmospheric side of the external dielectric plate. (C) a power supply for supplying alternating power to the antenna to generate plasma in the chamber. (D) A heating lamp arranged on the atmospheric side of the external dielectric plate. (E) An internal dielectric plate arranged on the vacuum side of the external dielectric plate so as not to contact the external dielectric plate. (F) a light absorbing layer formed in close contact with the internal dielectric plate, the light absorbing layer having a higher light absorptivity than the material forming the external dielectric plate and the internal dielectric plate, and made of an electrically insulating material; (G) An object holder for holding an object to be subjected to plasma processing inside the chamber. 14. A plasma processing apparatus having the following configuration. (A) A vacuum evacuable chamber at least partially made of a flat external dielectric plate. (B) An antenna arranged on the atmospheric side of the external dielectric plate. (C) a power supply for supplying alternating power to the antenna to generate plasma in the chamber. (D) A heating lamp arranged on the atmospheric side of the external dielectric plate. (E) an internal dielectric plate arranged on the vacuum side of the external dielectric plate so as not to contact the external dielectric plate, the internal dielectric plate being made of a material having a higher light absorptivity than the material constituting the external dielectric plate . (F) An object holder for holding an object to be subjected to plasma processing inside the chamber. 15. The material of the outer dielectric plate is quartz,
The material of the internal dielectric plate is AlN, BN, Si ₃ N ₄ , Si
C, plasma processing apparatus according to claim 14, wherein a is either Al ₂ O _3. 16. An internal dielectric plate comprising CrO ₂ , SiC,
The plasma processing apparatus according to claim 15, wherein any one of fine particles of carbon black is mixed.