JPS6115976A - Plasma reaction device and method for use thereof - Google Patents

Abstract

PURPOSE:To prevent the sticking of dust to substrates and to effect uniform reaction by inserting a substrate holding part on which the plural substrates are imposed into a reaction tube, rotating the holding part during plasma reaction and controlling the substrate temp. by the heating source on the outside of the reaction tube. CONSTITUTION:A carrier 32 on which the plural substrates 31 are set is inserted into the reaction tube 27 of a plasma reaction device from above or below and is fixed thereto. The inside of the tube is evacuated through a discharge port 23 and a reactive gas is introduced into the tube through an introducing port 21. Plasma is generated by a high-frequency coil 33 to effect the formation of a plasma CVD film on the surface of the substrates 31, the reaction of the substrates 31 and the introduced gas, the surface etching of the substrates 31, etc. while the pressure reduced to a specified value is maintained. The substrate holding part 29 is rotated and the temp. of the substrates 31 is controlled by a heater 28 during this time. The variance of the temp. between the substrates 31 is decreased by such mechanism, by which the uniformity of the plasma reaction is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a plasma reactor and method of using the same. More specifically, in the production of solid-state devices, plasma vapor deposition films are formed on arbitrary substrates, plasma reacts between the substrate surface and introduced gas, or plasma etching is performed on the substrate surface. A reactor is provided.

Conventional Structures and Their Problems Conventionally, many types of CVD apparatuses have been manufactured, and two representative examples are shown in FIG.

FIG. 1(a) shows a horizontal CVD apparatus with gas inlet 1.
High frequency coil 21 reaction tube 3. Exhaust port 4. The heater 6 and the exhaust port 6 are arranged so that the heater 5 is inclined with respect to the gas flow so that the CVD film is evenly deposited on the plurality of substrates θ. However, in this device, although there is little variation in the CVD film within the substrate 6, among the plurality of substrates 6, the one near the gas inlet 1 is thicker, and the one closer to the exhaust port 4 is thinner. Further, since the heater and the substrate are brought into close contact with each other and the substrate is heated by thermal conduction, if the substrate is bent, temperature unevenness will occur within the substrate, and the generated CVD film will be uneven.

FIG. 1(b) shows a C-coupled plasma CVD apparatus,
Gas inlet 11, high frequency electrode 121, reaction chamber 13° exhaust port 14. A plurality of substrates 17 are set on the heater 16 via a susceptor 16, and the susceptor 16 is rotated to reduce variations among the substrates, thereby improving the drawbacks of the horizontal type.

However, in both methods, since the substrate faces upward, dust that causes pinholes in the CVD film and vapor deposits (for example, Si02) formed by reactions in the gas are present.
It has the disadvantage that the same reactants (8102 particles formed in the reaction gas) tend to fall and adhere to the surface, and the uniform C
This is an obstacle to VD film formation.・ Furthermore, no consideration was given to automation in the placement of the substrates, and since the placement of the substrates was carried out one by one, there were often cases where the substrates were damaged or dropped.0 Purpose of the Invention Therefore, the present invention was developed. In view of these problems, the aim of the company is to provide a plasma reactor that can reduce dust on the substrate as much as possible, uniformly, and automatically place the substrate. The object of the present invention is to provide a plasma reaction device that can be used as an oxidation or tinodization film forming device or a plasma etching device, and a method for using the same.

Structure of the Invention The present invention provides a method in which a reaction tube equipped with a reaction gas inlet, a plasma generation section, an exhaust port, and a substrate insertion port is installed vertically, and a heater is installed as a heating source outside the reaction tube. A capacitive electrode Setake coil is installed for plasma generation, the substrate can be placed inside the reaction tube, and a holding part is provided which can be inserted into and taken out from the inside of the reaction tube from above or below. The holding part is rotatable, and the holding part on which the substrate is placed can be inserted with the surface facing downward while the gas flow inside the reaction tube is directed downward. The present invention provides a characteristic plasma reactor and a method for using the same.

Description of examples A device according to one embodiment will be described below with reference to the drawings.

FIG. 2 shows a sectional view of a plasma reactor according to an embodiment of the present invention. In this device, the reaction gas inlet 21. Plasma generation section 22. Exhaust port 23° Heat-resistant gasket 24. Cooling water pipe 25. Integral 262 reaction tube 27. resistance heater 28
．． The substrate holding part 29 is composed of a substrate insertion port cover 30, and a carrier 32 with a plurality of substrates 31 set with their intended surfaces facing downward can be inserted from the bottom. −
After fixing the carrier 32, the air is evacuated from the exhaust port 23 to create a vacuum, and the evacuation is continued while introducing the reaction gas from the reaction gas inlet 21, while maintaining a constant state of reduced pressure.
It has a structure in which plasma is generated by the high frequency coil 33 to form a plasma CVD film on the surface of the substrate 31, the substrate surface is reacted with an introduced gas, and the substrate surface is etched. Note that at this time, the substrate temperature is controlled by the heater 28.

When performing plasma CVD using this apparatus, for example,
When depositing Si3N4 on the substrate, 5iH2Ct
2. A mixed gas such as NH3, Ar, etc. may be used, and when performing a reaction with the introduced gas, such as oxidation or nitridation,
If the substrate is Si, St○2 is formed using a mixed gas such as 021 Ar, or -c is formed using NH3°Ar or the like.
S i 3N4 can be formed.

Furthermore, when etching the substrate, the substrate is S
It can be etched as S s F4 using tl et al. SF6 or the like.

Note that in the plasma reaction apparatus shown in this embodiment, by rotating the substrate holding part 29 during plasma reaction, it is possible to make variations in the substrate more uniform. In addition, when inserting the substrate, the gas flow inside the reaction tube is directed downwards, and by inserting the holder with the substrate on it so that the surface is facing downward, dust and foreign matter can be prevented from adhering to the substrate surface. can be prevented.

In addition, in FIG. 2, 34 is a pyrometer, 36 is a gas supply device, 36 is a mechanical booster pump, 37 is a rotary pump, 38 is a loader, 39 is a peephole, and arrow A represents the rotation of the substrate holder, B represents the reactant gas flow. Moreover, FIG. 2 shows a case where the furnace body 26 is erected almost perpendicularly to the ground.

Effects of the Invention According to this apparatus, (1) Since the inside of the reaction tube 27 is in a reduced pressure state and the target surface of the substrate 31 can be set downward, dust is less likely to adhere to the target surface of the substrate during the reaction.

(2) When the carrier 32 is inserted, air flows downward, so dust does not fly up.

(3) Since the substrate 31 is heated by the radiant heat of the reaction tube 27, there is little variation in temperature within the substrate 31 and between the substrates 31, and the uniformity of the plasma reaction is good.

(4) The substrate 31 can be placed on the carrier 32 automatically.

(6) Since the plasma generating section 22 is located away from the substrate and ionized particles do not directly collide with the substrate surface, damage caused by positive ions or electrons can be reduced even when the substrate is a semiconductor element.

Demonstrates excellent effects such as

Although the examples show the case where the reaction tube is vertical, the same effect can be obtained even when the reaction tube is tilted.

As described above, the plasma reaction device of the present invention can prevent dust from adhering to the substrate as much as possible, and can form a CVD film with a uniform thickness, and can perform etching after forming an oxide film or a nitride film. can.

Furthermore, it is a device that can be fully automated, from inserting the substrate to displaying the number of plasma reactions.

In addition, it is also possible to perform a plasma reaction while applying a stronger magnetic field to the outside of the furnace body of this apparatus so as to be parallel to the substrate surface, and to improve the film quality by the cyclotron movement of electrons. Furthermore, it is also possible to add a grid electrode as shown at 40 in FIG. 2 to introduce only excitons to the substrate side.

[Brief explanation of the drawing]

FIG. 1 (-) is a schematic diagram of a conventionally used horizontal CVD device, FIG. 1 (inside) is a schematic diagram of a vertical CVD device, and FIG. FIG. 21... Reaction gas inlet, 22... Plasma generation part, 23... Exhaust port, 26...
...Furnace body, 27...Reaction tube, 29...
Substrate holding part, 31... Substrate, 32...
Carrier, 30... Board insertion port.

Claims (4)

[Claims] (1) A reaction tube equipped with at least a reaction gas inlet, a plasma generation section, an exhaust port, and a substrate insertion port is installed vertically, and at least a heating source and a plasma generation electrode or coil are installed outside the reaction tube. What is claimed is: 1. A plasma reaction apparatus, further comprising: a holding section that can place a substrate inside the reaction tube and that can be taken in and out of the reaction tube from above or below. (2) The plasma reaction apparatus according to claim 1, wherein the holding part has a structure that can be rotated from the outside of the reaction tube. (3) The step of placing the substrate on the holding part, the step of inserting the holding part with the substrate placed thereon into the upright reaction tube from above or below, and once exhausting the gas in the reaction tube through the exhaust port. After that, a reaction gas is introduced while continuing to evacuation, and a high frequency electric field is applied from outside the reaction tube under a constant pressure to generate plasma to form a plasma vapor deposition film on the substrate surface. A method of using a plasma reactor, characterized by causing an introduced gas to undergo a plasma reaction and plasma etching the surface of the substrate. (4) The plasma reaction apparatus according to claim 3, wherein the holding part on which the substrate is placed is inserted so that the surface thereof faces downward while the gas flow inside the reaction tube is downward. How to use.