JPS63150914A - Device for forming thin film - Google Patents

Abstract

PURPOSE:To manufacture a thin-film forming device capable of forming a thin-film having uniform film thickness and resistance value, etc., and high quality by providing a rolling mechanism, in which a susceptor, a base surface, of which for a body to be treated is shaped in approximately the vertical direction, is rotated in a reaction furnace, and an excitation means through which a reaction fluid is excited and the thin-film is formed onto the surface of the body to be treated. CONSTITUTION:When wafers 5 are placed onto a susceptor 6, the susceptor 6 is turned by driving a rotaty drive control section 6 while an induction 11 is supplied with high-frequency power, and the susceptor 6 and each wafer 5 are heated. A reaction medium C is flowed into a bell jar 1 from a gas inflow port 2 after plasma cleaning while being discharged quickly from a discharge port 3 by driving a vacuum pump 4. Ultraviolet rays emitted from a mercury-arc lamp 15 are converted into parallel beams by a concave mirror 16, and applied vertically to respective wafer 5. Accordingly, the reaction medium G is excited and turned into an intermediate product and adsorbed to the wafers 5, thus forming epitaxial layers onto the surfaces of the wafers 5.

Description

[Detailed Description of the Invention] [Industrial Field of Application] [Prior Art] For example, there are various methods for epitaxial single crystal growth equipment, such as a resistance heating method and a high-frequency induction heating method. This method grows epitaxial single crystals by heating. For example, there is a barrel-type device that uses high-frequency induction heating, and this uses a multifaceted vertical susceptor that places a semiconductor substrate (hereinafter referred to as a wafer) as an object to be processed inside a bell jar whose inner wall is coated with metal. silicon tetrachloride (SiC/
In this method, a reactive gas such as l+) is introduced and heated by an induction coil from outside the bell jar to make the temperature distribution on the wafer surface uniform, thereby growing an epitaxial single crystal on the wafer surface.

By the way, in recent years, in contrast to the above heating methods, attention has been paid to performing epitaxial single crystal growth at a low temperature, for example, room temperature to 400 degrees Celsius. This technique involves flowing a reaction medium called a source gas into a bell jar and exciting this reaction medium with light, plasma, etc. to grow an epitaxial single crystal on the wafer surface. Specifically, a susceptor with a wafer horizontally placed in the bell jar is placed, and in this state, a reaction medium is flowed into the bell jar and the reaction medium is excited with light. Due to this optical excitation, for example, source gas molecules are changed into intermediate products containing neutral radical ions, and these intermediate products are adsorbed onto the wafer surface. Then, an elimination reaction or the like occurs on the wafer surface, and silicon atoms are generated on the wafer surface, that is, an epitaxial single crystal is generated.

[Problem that the invention seeks to solve]

However, intermediate products are generated due to the excitation of source gas molecules, but if this reaction occurs in the gas phase or on a Pelger, the intermediate products become particles and are removed from the wafer during epitaxial mono- and antagonistic crystal formation. It will fall onto the surface. As a result, the uniformity of the film quality, film thickness, resistance value, etc. of the epitaxial layer deteriorates, making it impossible to obtain a high quality epitaxial layer. This deterioration in quality also applies to doping molecules, and the thickness and resistance value of the epitaxial layer become non-uniform.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a thin film forming apparatus that can form a high quality thin film with uniform film thickness, resistance value, etc.

[Means for solving problems]

The present invention provides a reactor into which a reaction medium flows and is discharged, a susceptor in which a surface for placing an object to be processed is provided in a substantially vertical direction within the reactor, and a surface for placing a film on the susceptor. This thin film forming apparatus is equipped with a rotation Rm having a rotating shaft connected to the back surface, and an excitation means for exciting a reaction fluid to form a film on the surface of an object to be processed, thereby achieving the above object.

[Effect]

By having such a means, the object to be processed can be treated! S,
! A susceptor whose surface is arranged in a substantially vertical direction is rotated by a rotating structure in a reactor, and at this time, the reaction medium flowing into the reactor and being discharged is excited by an excitation means to form a film on the surface of the object to be treated. is formed.

〔Example〕

A first embodiment of the present invention will be described below with reference to the configuration diagram of a thin film forming apparatus applied to epitaxial single crystal production shown in FIG.

A bell jar 1 serving as a reactor is provided with a gas inlet 2 for a reaction medium, which is a source gas or a dopant gas, in the upper part, and a gas outlet 3 in the lower part opposite to the gas inlet 2. A vacuum pump 4 is provided at this gas discharge port 3 so that the reaction medium G can be rapidly discharged. Further, inside the verge v-1, a cylindrical susceptor 6 for holding a plurality of wafers 5 has a wafer mounting surface 7 in a substantially vertical direction, and this wafer mounting surface 7 is connected to the gas inlet 2 and the gas exhaust port 2. It is arranged at a position that does not exceed the position facing the outlet 3, so that the reaction medium C flows parallel to the surface of the wafer [1 side 7].

A rotary shaft 8 constituting a rotary printing mechanism is connected to the back surface of the susceptor 6 relative to the wafer mounting surface 7, and the rotary shaft 8 is rotated, for example, in the direction of arrow (A) by a rotational drive control section 9 composed of a motor or the like. It is designed to be rotated at a predetermined rotation speed. Furthermore, an induction coil 11 is provided on the back side of the susceptor 6 with a quartz shield 10 interposed therebetween.

On the other hand, a plasma electrode 12 is arranged at a position facing the wafer mounting surface 7 of the susceptor 6, and a high frequency power source 13 is connected to the plasma electrode 12.

Roughly, wafer Il of susceptor 6! Excitation means for exciting the reaction medium G is provided at a position facing the mounting surface 7. That is, this excitation means is composed of a mercury lamp 15 whose lighting is controlled by a lighting control section 14 and a concave mirror 16 which is a quartz plate coated with a metal film.
is placed at the focal point of the concave mirror 16, and this mercury lamp 1
The ultraviolet rays emitted from the wafers 5 are converted into parallel light by the concave mirror 16, and are irradiated perpendicularly onto the surface of each wafer 5. In addition, in order to prevent vapor deposition on the concave mirror 16 during the reaction, the mercury live 15, the concave mirror 16 side and the susceptor 6
, a shield plate may be formed between the gas inlet 2 and the gas outlet 3 by means of a shield plate that transmits ultraviolet light.

Next, the operation of the apparatus configured as described above will be explained. When the wafer 5 is placed on the susceptor 6, the susceptor 6 is driven by the rotational drive control unit 6 to rotate in the direction of arrow (A) at a predetermined rotation speed, and high-frequency power is supplied to the induction 11, so that the susceptor 6 and each Wafer 5 is heated. In this state, the high frequency power source 13 is connected to the plasma electrode 1.
A high frequency voltage is applied to the wafer 2, and each wafer 5 is plasma cleaned. Thereafter, the reaction medium G flows into the Pelger 1 through the gas inlet 2 and is rapidly discharged from the exhaust port 3 by driving the vacuum pump 4 . Then, the mercury lamp 15 is turned on by the lighting unit 1i1111, and the ultraviolet rays emitted from the mercury lamp 15 are directed to the concave mirror 1.
The light is converted into parallel light by the reflection action of 6, and is irradiated perpendicularly to the surface of each wafer 5. In this way, the reaction medium G is excited and changed into an intermediate product, which is adsorbed onto the wafer 5.

Then, a desorption reaction occurs in each wafer 5, and an epitaxial layer is formed on the surface of each wafer 5.

In this way, in the first embodiment, the wafer mounting surface 7 of the susceptor 6 is installed in a substantially vertical direction and rotated, and at the same time, the reaction medium G is introduced and rapidly discharged. is excited using a mercury lamp 15, so even if the intermediate products become particles, they do not fall onto the surface of each wafer 5, and are quickly discharged from the discharge port 3, preventing the generation of particles. I'm suppressing it. Also, since the susceptor 6 rotates, the reaction medium/body G
Even if the flow is non-uniform, a uniform gas concentration is supplied to each wafer 5, and the temperature distribution on the surface of the wafer 5 is roughly made uniform. On the other hand, since the excitation by ultraviolet rays is converted into parallel light by the concave mirror 16, uniform excitation can be performed on the surface of each wafer 5. Therefore, the epitaxial layer formed on each wafer 5 has a uniform thickness and resistance value and is of high quality. Note that since the plasma electrode 12 is provided, an epitaxial layer can be formed by plasma CDV.

Next, a second embodiment of the present invention will be described with reference to groove diagrams of the IIK forming apparatus shown in FIGS. 2 and 3. Note that the same parts as in FIG. 1 are given the same reference numerals, and detailed explanation thereof will be omitted. This device excites the reaction medium G using laser light, and the excitation means has the following configuration. That is, seven laser oscillators 20, 21, . Correspondingly Pelger 1
Laser passing window W1 made of a material that passes ultraviolet rays
, W2...Wl are formed. Note that only two laser oscillators 20 and 21 are shown due to the drawing. By the way, concave and convex lenses R1, R4... are provided on the output window side of each laser oscillator 20, 21..., and the laser beams L1, L2 oscillated from each laser oscillator 20, 21...
...L7 are concave and convex lenses R1...R4...
The beam is spread out in two directions and irradiated into the Pelger 1. By the way, each laser passing window W1, W
2...Convex surfaces IQ1, Q2...Q7 are formed on the inner wall of the Pelger 1 facing Wl, as shown in the cross-sectional view of the laser passing windows W1, W2,...W7 in FIG. . These convex mirrors Q1, Q2...Q7 are each formed by coating their surfaces with a material that has a high reflectance for ultraviolet rays, and are irradiated with laser beams L1, L2...
・Acts to expand L7 in the XY direction. Note that these convex mirrors Q1, Q2, . . . , Q7 are constantly cooled by being supplied with air, thereby preventing reactions from occurring on their surfaces. In addition, the reason why the laser oscillators 20, 21... are set to an odd number, for example 7, is because of the laser passing windows W1, W2...W.
This is because of the formation positional relationship between l and each convex surface tiQ1, Q2...Q7, and if an even number is used, it becomes difficult to form a laser passing window.

Next, the operation of the second embodiment will be explained. The susceptor 6 on which the wafer 5 is placed is rotated by the drive of the rotational drive control section 6, and high frequency power is supplied to the induction 11 to heat the susceptor 6 and each wafer 5. In this state, a high frequency voltage is applied from the high frequency power supply 13 to the blaster electrode 12, and each wafer 5 is plasma cleaned.

Thereafter, when the reaction medium G flows into the Pelger 1 from the gas inlet 2, this reaction medium G is rapidly discharged from the discharge port 3 by driving a vacuum pump (not shown). Then, each laser oscillator 20, 21... operates to oscillate laser beams L1, L2...L7, respectively. These laser beams Ll, L2...L7 are first transmitted to the concave and convex lenses R1...
- Laser passing window W expanded in two directions by R4...
1, W2...W7 and is irradiated into the inside of the verge 'rP1. Then, each of the irradiated laser beams L1, L
2... are convex mirrors Q1, Q2...Q7 located at opposite positions
It is reflected and spread out in the X and Y directions. Therefore, the front surface of the am surface 7 of the susceptor 6 is uniformly irradiated with laser light.

In this way, the reaction medium G is excited in front of the mounting surface 7 of the susceptor 6 to generate an intermediate product, and this intermediate product is adsorbed onto the wafer 5. Then, a desorption reaction occurs in each wafer 5, and an epitaxial layer is formed on the surface of each wafer 5.

In this way, in the second embodiment, the laser oscillators 20, 21, .
2...L7 is expanded and reflected by the convex mirrors Q1, Q2...Q7, so it goes without saying that the same effect as in the first embodiment can be achieved, and in addition, each laser beam L1
, L2, . The excitation effect is improved on the front surface of the mounting surface 7, and uniform excitation can be achieved. Therefore, an epitaxial cell layer with improved quality can be formed.

Next, a third embodiment of the present invention will be described with reference to FIG. Note that the same parts as in FIG. 1 are given the same reference numerals, and detailed explanation thereof will be omitted.

This device uses ECR plasma as an excitation means. That is, a plasma outlet is formed in the wall portion of the Pel jar 1 facing the mounting surface 7 of the susceptor 6,
Plasma reaction at this plasma outlet! 30 are provided. A magnet 3 is attached to the outer periphery of this plasma reaction base 30.
1 is wound so that a magnetic field can be applied inside the plasma reactor 30. A waveguide 32 is provided on the side facing the Pelger 1 of the plasma reaction 30, and microwaves are made to enter the plasma reaction chamber 30 through the inside of this waveguide 32.

Note that the microwave satisfies resonance frequency conditions in the plasma reaction chamber 30. Further, the gas inlet 33 is provided above the installation position of the waveguide 32 in the plasma reaction chamber 30.

With such a configuration, the plasma reaction space 30
The inside of the is filled with a magnetic field, and microwaves are incident through the waveguide 32, and the microwaves are generated during the plasma reaction.
resonate within. When the reaction medium G flows into the plasma reactor 30 from the gas inlet 33 in this state, the reaction medium G is excited and turned into ECR plasma. A part of this plasma then flows into the Pelger 1 due to the leakage flux of the magnetic field of the magnet 31. Thus,
Plasma flows to the surface of each wafer 5, and epitaxial single crystal growth is performed on the surface of each wafer 5. Note that the reaction medium G that has been turned into plasma is rapidly discharged from the gas discharge port 3 by a vacuum pump (not shown). Therefore, the third embodiment can also achieve the same effects as the first embodiment. Note that by placing the plasma Im in front of the mounting surface 7 of the susceptor 6, plasma CDV and plasma cleaning can be performed.

Next, a fourth practical example of the present invention will be explained with reference to FIGS. 5 and 6.

This device uses an electron gun 40.41.42.4 as an excitation means.
3 was used. These electron guns 40 to 43 are arranged at equal intervals around the outer circumference of the Pelger 1. Electron lenses 44 to 47 are provided at the locations where the electron guns 40 to 43 are arranged, as shown in the cross-sectional view of the location where the electron guns 40 to 43 are arranged in FIG.
Electrons emitted from the susceptor 43 become parallel and spread electron beams and are irradiated onto the mounting surface 7 of the susceptor 6. Note that the electron beam is set to be irradiated onto the mounting surface 7 at a predetermined low angle. Further, 47 to 50 are returning electrodes to which a negative voltage is applied.

With such a configuration, electrons are emitted from each of the electron guns 40 to 43, and these electrons are converted into a parallel and spread electron beam by each of the electron lenses 44 to 47, and are sent into the Pelger 1 at high speed. It is incident. Then, each electron beam passes through the tarding electrodes 47 to 5o, is decelerated, and is incident on the surface of the a placement surface 7 of the susceptor 6 at a low angle. As a result, the source gas molecules adsorbed on the surface of each wafer 5 are excited, and an epitaxial single crystal is formed on the surface of each wafer 5. Therefore, the fourth real m
This example can produce the same effects as the first example. Although FIG. 6 shows the electron beam uniformly irradiating the surface of each wafer 5, it can actually be uniformly irradiated by controlling the electron lenses 44 to 47. . Note that since the retarding conductors 47 to 5o are provided, the electron beam will not be scattered.

Note that the present invention is not limited to the above embodiments, and may be modified without departing from the spirit thereof. For example, it can be applied not only to epitaxial single crystal growth but also to various etching processes.

〔Effect of the invention〕

As described in detail above, according to the present invention, it is possible to provide a thin film forming apparatus capable of forming a thin film of high quality with uniform film thickness and resistance value.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a first embodiment of a thin film forming apparatus according to the present invention applied to epitaxial single crystal growth, and FIGS. 2 and 3 are configurations showing a second embodiment of the present invention apparatus. 4 are block diagrams showing a third embodiment of the apparatus of the present invention, and FIGS. 5 and 6 are block diagrams showing a fourth embodiment of the apparatus of the present invention. DESCRIPTION OF SYMBOLS 1... Pelger, 2... Gas inlet, 3... Gas outlet, 4... Vacuum pump, 5... Wafer, 6...
... Susceptor, 8... Rotating shaft, 9... Rotation drive control unit, 11... Induction coil, 12... Plasma reaction electrode, 13... High frequency power supply, 14... Point control unit , 15... Mercury lamp, 16... Concave mirror, 20
．． 21...Laser oscillator, R1, R4...Concave and convex lens, W1-W7...Laser passing window, 01-Q7...
Convex mirror, 30... Plasma reaction =, 31... Magnet, 32... Waveguide, 33... Gas inlet, 40
~43...Electron gun, 44-47...Electron lens. No. 1 Figure 3 Figure 5 Figure 6

Claims (1)

[Claims] A reactor into which a reaction medium flows and is discharged, a susceptor in which a surface for placing the object to be processed is provided in a substantially vertical direction, and a rotating shaft on the back surface of the susceptor corresponding to the surface for placing the object. A thin film forming apparatus comprising: a rotating mechanism connected to each other; and excitation means for exciting the reaction fluid to form a thin film on the surface of the object to be processed.