JPS61214523A - Plasma reaction processor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to plasma reaction processing technology, and is effective for use in, for example, depositing a thin film on a semiconductor substrate and processing the thin film in the manufacture of semiconductor devices. related.

[Background technology]

As is well known, when manufacturing semiconductor devices, deposition (generation) processing of thin films such as silicon nitride films and silicon oxide films,
And processing (etching) of these films is frequently used.

Conventionally, heating reaction treatment using heat has been implemented as a means for these reaction treatments.

In recent years, plasma reaction processing using plasma has been increasingly utilized for the purpose of low-temperature processing and microfabrication processing.

Conventionally, these plasma processing apparatuses have been used to process K between parallel plate electrodes in vacuum, as described in Electronic Materials (Industrial Research Association) published on March 1, 1983, starting from page 31.
l 3.56 (MHz) high frequency power is applied,
A semiconductor wafer, which is a plasma reaction product, is grounded to one side of both electrodes, a reaction gas is supplied, and plasma ion etching is performed.

Since the above-described method uses glow discharge as the plasma reaction treatment, the ionization efficiency is low and the plasma processing speed such as the etching rate is slow.

In addition, due to the shape of the parallel plate electrodes, the glow discharge state differs and the directionality of the plasma treatment occurs, making it impossible to perform uniform plasma treatment. It was found that plasma reaction treatment with good reproducibility was not possible because of the

[Purpose of the invention]

An object of the present invention is to provide a processing method and apparatus for eliminating the drawbacks of conventional plasma reaction processing, increasing the speed of plasma reaction processing, and performing plasma reaction processing with high uniformity.

That is, regarding the processing speed, when thin films are being deposited, the deposition speed is increased, and when thin films are processed, the processing speed is increased.

Regarding uniformity, it is an object of the present invention to provide an apparatus that performs plasma processing with less variation in deposited film thickness, processing depth, and processing width.

The above objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Summary of the invention]

A brief summary of typical inventions disclosed in this application is as follows.

That is, while electromagnetic waves such as microwaves are concentratedly propagated as high-density electromagnetic waves in the plasma reaction treatment region, a strong magnetic field is applied to increase activation of the electron movement of the electromagnetic waves.

As a means of supplying the reaction gas and the object to be processed to this region, increasing the plasma ionization efficiency of the reaction residue, increasing the plasma reaction processing speed, and increasing the uniformity of the plasma reaction processing,
Reactant gas is dispersed from the microwave propagation electrode and supplied to the object to be treated. At the same time, the electrode or the object to be treated is rotated to perform plasma reaction treatment, and the plasma reaction ions acting on the object to be treated are evenly distributed. I'll give it a 5.

In addition, as a uniform plasma reaction treatment means, the microwave electric field intensity distribution constituted by the microwave propagation electrode is variably controlled, the amount of plasma ions acting on the object to be treated is equalized, and uniform treatment is performed.

As the microwave electric field strength distribution control means, a reflection terminal capable of controlling the movable amount of a reflection plate is provided in the microwave transmission circuit, and the microwave electric field strength distribution is controlled by moving this reflection plate. .

In addition, in order to obtain reproducibility of the plasma reaction, K is the only factor in the plasma reaction treatment, such as microwave, strong magnetic field, and reaction gas. is supported on the ground on a temperature-controllable support stand, and plasma reaction treatment is performed while maintaining it at a predetermined temperature.

[Embodiment 1] FIG. 1 is a sectional view of a main part of a plasma etching processing apparatus for etching a silicon oxide film on a semiconductor wafer in semiconductor wafer manufacturing according to an embodiment of the present invention.

To explain the device configuration, the processing section waveguide 1 has a susceptor 2 made of quartz that transmits microwaves, and water 4 whose temperature is maintained by an electronic cooling device 3 is supplied into the susceptor 2. The susceptor 2 is kept at a constant temperature.

On this susceptor 2 is placed a sea urchin 6 on which a silicon oxide film 5 is formed, the pattern to be etched being masked by a resist. A tooth-shaped slow wave electrode 7 is constructed above the wafer 6, and when microwaves are propagated,
A concentrated electromagnetic field is formed between the susceptor 2 and the tooth-shaped slow wave electrode 7.

On the other hand, the tooth-shaped slow wave electrode 7 is provided with a plurality of waste supply ports 8, and a reaction gas 10 supplied from a gas supply section 9 is provided.
is supplied to the processing sea urchin 8 6 at equal pressure.

A magnet 11 is installed on the outer periphery of the processing section waveguide 1.
A strong magnetic field acts within the processing section waveguide l.

Further, microwaves are passed through both sides of the processing section waveguide 10,
There is a vacuum shield plate 12 to maintain airtightness, and the exhaust section 1
3, the inside of the processing section waveguide 1 is kept in a vacuum state.

On the other hand, microwaves are generated by the microwave generating section 15, passed through the circulator 16, propagated to the processing section waveguide 1, and configured as concentrated microwaves 17 under the tooth-shaped slow wave electrode section 7.

Note that microwaves that are not involved in the plasma reaction process are reflected by the reflection plate 1'lC configured in the reflection termination section 18,
The light propagates in the opposite direction, is guided by the circulator 16 to the dummy load 20, is converted into heat, and disappears. In particular, the aforementioned reflector 19 is IJ.

It is moved left and right by a drive motor 21.

The overall control section 22 controls the amount of microwave output generated by the microwave generation section 15, controls the electronic cooling/heating device 3 that adjusts the temperature of the susceptor 2, controls the amount of movement of the reflection plate 19, and supplies gas from the gas supply section 9. Classifies the gas types and controls the gas amount.

Next, a method of etching the silicon oxide film 5 formed on the wafer 6 using this apparatus will be explained. A wafer 6 on which a pattern of silicon oxide [5] to be etched is masked with a resist film or the like to be etched is set on the susceptor 2, and an exhaust section 13 is used to guide the processing section waveguide 1.
Create a high vacuum inside. When microwaves are generated from the microwave generator 15 in this high vacuum state, concentrated microwaves 17 are generated under the tooth-shaped slow-wave electrode 7. At the same time, due to the action of the strong magnetic field from the magnet 11, the electrons in the microwaves undergo cycloidal movement. , excited. When a reactive gas 10 is supplied from the gas supply section 9 to this region, the excited electrons and the reactive gas 10 molecules collide violently, and the reactive gas molecules are ionized and become a plasma state. The silicon oxide film is etched by the plasma ions.

The reflection plate 19 is moved by the linear pulse motor 2 to uniformly perform this plasma etching process, and the intensity distribution of the concentrated microwave 17 acting on the processing wafer 6 is varied, so that the plasma ions are the object to be processed. The etching process is performed uniformly on the silicon oxide film 5 to perform a uniform etching process.

Note that the means for generating concentrated microwaves is not limited to the tooth-shaped slow-wave electrode shown in FIG. 1 (it may also be configured with a microstrip line shown in FIG. 2, 11C, and f) or an antenna pair shown in FIG. 3.

Briefly explaining FIG. 2, the microwave 23 propagates through the center conductor 25 of the coaxial cable 24,
is transmitted to the microstrip line 27 provided, and is transmitted from the center conductor 28 to the coaxial cable 29. During this time,
Concentrated microwaves are generated near the microstrip line 27.

In FIG. 3, a rotating upper antenna 30 is provided with distributed gas supply ports 31 to supply a reactive gas 32. In FIG.

On the other hand, exhaust ports 34 are similarly distributed in the lower antenna 33.
is provided to evacuate the processing space.

Note that the microwave 35 propagates in a concentrated manner from the upper antenna 30 to the lower antenna 33.

On the other hand, the processed wafer 36 is held on a support base 37 made of a material that transmits microwaves, such as quartz, in a state where the contact area is reduced.

〔effect〕

(1) The present invention applies a strong magnetic field to a high-density electric field region in which microwaves in the GH2 frequency band propagate intensively under high vacuum, activates the electron movement in the electromagnetic waves, and applies a reactive gas to that region. Since the object to be processed is supplied, the probability of collision between the reaction gas and electrons increases, plasma ionization efficiency becomes extremely high, and the plasma reaction processing speed can be increased.

(2) As mentioned in item (1) above, plasma ions are guided by extremely high-frequency microphone waves, so plasma reaction processing is performed with a small electric field strength, so the impact force of plasma ions on the object to be processed increases. will be weakened and damage will be reduced.

(3) Since the microwave electric field intensity distribution acting on the object to be processed can be variably controlled, the amount of plasma ions acting on the object to be processed can be controlled in terms of quantity, and the amount of plasma ions can be applied evenly, resulting in improved uniformity. Capable of high-quality plasma processing.

Although the present invention has been specifically explained above based on the embodiments, the present invention is not limited to the above embodiments. It goes without saying that moderate modifications can be made without departing from the spirit.

Note that the present invention relates to plasma reaction treatment,
A plasma reaction processing apparatus capable of depositing various films or processing these films is provided.

In addition, by using a microwave beam antenna, it is possible to irradiate microwaves in a beam (spot) in a concentrated manner, and it is also possible to perform plasma treatment on localized areas of the object to be treated. A microwave concentration region may be formed only on the surface of the object to be processed by the circuit electrode.

[Application field]

The above explanation will mainly relate to the case where the invention made by the present inventor is applied to a plasma etching processing apparatus for etching a silicon oxide film formed on a semiconductor wafer in semiconductor device manufacturing, which is the field of application in which the invention was made by the present inventor. Although described above, the invention is not limited to this, and can be applied to, for example, a plasma processing method for semiconductor materials and all other substances that can be subjected to plasma reaction processing.

For example, plasma vapor deposition processing equipment (CVD equipment),
It can be applied to plasma processing equipment in all fields, including plasma polymerization processing equipment, plasma development processing equipment, plasma asher equipment, etc.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of a plasma etching processing apparatus according to Example 1, FIG. 2 is a microstrip line, and FIG. 3 is a structural diagram of an electrode for generating concentrated microwaves by an antenna pair. DESCRIPTION OF SYMBOLS 1... Processing part waveguide, 2... Susceptor, 3... Electron cooling, 4... Water, 5... Silicon oxide film, 6...
- Wafer, 7... tooth-shaped slow wave circuit electrode, 8... gas supply port, 9... gas supply section, 10... reaction gas, 11
...Magnet, 12...Vacuum shield plate, 13...Exhaust section, 14...Exhaust, 15...Microwave generation section,
16...Circulator, 17...Concentrated microwave, 18...Reflection termination section, 19...Reflection plate, 20...
・Dummy load, 21...lJ near pulse motor, 2
2... Overall control unit, 23... Microwave, 24...
・Coaxial cable, 25... Center conductor, 26... Multi-stage slit, 27... Microstrip line, 28...
- Center conductor, 29... Coaxial cable, 30... Upper antenna, 31... Gas supply port, 32... Reactive gas,
33... Lower antenna, 34... Exhaust port, 35...
Microwave, 36... wafer, 37... support stand.

Claims (1)

[Claims] 1. A vacuum processing section, an electromagnetic wave emitting means for propagating electromagnetic waves in the vacuum processing section, a means for intensively propagating the electromagnetic waves in a limited direction, and a plasma reactive gas in the vacuum processing section. A plasma reaction processing apparatus comprising: a gas supply section for supplying gas; and a processing object supply section for supplying a processing object.