JPS63192238A - Vapor phase reaction device - Google Patents

Abstract

PURPOSE:To prevent the dusting of a foreign matter and the generation of the nonuniformity of film thickness, the nonuniformity of impurity concentration, etc., by boring a through-hole to a wafer base surface for a wafer sample base, inserting a wafer push-up means into the through-hole and connecting the wafer push-up means to an evacuation means. CONSTITUTION:A wafer push-up means 30 is inserted slidably into a through- hole 20 bored to a wafer sample base 4 without generating a clearance, and connected to an evacuation means to a hollow shape. Consequently, the wafer push-up means 30 can hold a wafer 6 strongly through evacuation. Accordingly, the overall volume of the through-hole 20 can be reduced, and the through-hole 20 may be formed only at one position of the sample base, thus inhibiting an adverse effect having the uniformity of temperature distribution. The wafer push-up means 30 requires no pin relief cavity, thus improving the uniformity of the temperature distribution of the wafer sample base 4, then hardly generating the dispersion of the nonuniformity of film thickness and impurity concentration. Possibility in which a reaction gas intrudes onto the contact surfaces of the wafer push-up means 30 and the through-hole 20 and flakes are formed and attached is removed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of Industry 1°] The present invention relates to a gas phase reactor. More specifically, the present invention relates to a gas phase reaction apparatus having a wafer sample stage equipped with a wafer protrusion 1.1 mechanism that can improve film thickness uniformity.

[Prior art] One of the methods commonly used to form thin films for 1" conductor 1-X is chemical vapor deposition (
CVI):Chemical Vaporl)ep
OS it 1 on). CV l) refers to turning a gaseous substance into a solid substance through a chemical reaction and depositing it on the substrate 1-.

The characteristics of CV I) are that various thin films can be obtained at a deposition temperature considerably lower than the melting point of the thin film to be grown, and that the purity of the grown thin films is high, making it possible to form a thermal oxide film of Si or 5it-. Since the electrical properties are stable even when grown, it is widely used as a bansibasic film on the surface of a conductor.

Thin film formation by CV l) is performed, for example, at approximately 400°C-50°C.
A reactive gas (e.g. SiH
4+02. or S i H/11 +PHJ +02
). The reaction gas described in Section 1 is blown onto a wafer in a reactor (belljar), and 5i02 or phosphorus silicate glass (PSG) is applied to the surface of the wafer.
) or forming a thin film of borosilicate glass (BSG).

Further, two-layer film formation of 5i02 and PSG or BSG may be performed. Furthermore, molybdenum.

It can also be used to form metal thin films such as tungsten or tungsten silicide.

An example of an apparatus conventionally used for performing such a thin film forming operation by CVD is shown in FIG. 2 as a partial cross-sectional view.

In FIG. 2, a reactor (bell jar) 1 includes a conical bumper 2 covered with a conical cover 3,
1. A wafer sample stage 4 is installed around 1.
Wafers 6, which are workpieces, are sequentially supplied to the wafer sample stage 1-, and a wafer fork 7 is provided for sequentially carrying out the wafers.

In order to transfer the wafer 6 to the wafer fork 7, a wafer protrusion 1 and a pin 12 capable of lowering are housed inside the wafer sample stage. The reactor is provided with an openable and closable gate section 11 for introducing the wafer fork into the reactor.

A reaction gas inlet pipe 8 is connected to one point of the conical cover 3.The wafer sample stage 4 is supported by a support stage 9.A heating stage 12 is connected directly to the wafer sample stage 9.
is installed.

After the film formation on the wafer surface is completed, the wafer is taken out from the reactor in the following order of operations.

(1) Thrust 1-bin 1 stored in wafer sample stage 4
2 is l! (2) The fork 7 enters between the lifted wafer 6 and the wafer sample stage 4; (3) The protrusion 1-pin 12 is lowered and the wafer 6 is moved to the fork 7.
(4) The fork 7 moves to carry the wafer out of the reactor.

The operation of loading the wafer into the reactor is almost the reverse of this operation.

[Problems to be Solved by the Invention] However, according to the conventional technology, the wafer is held by moving one pin of the four wooden protrusions in the center of the sample stage, and the transfer fork is inserted there. Wafers were being transported.

The conventional protrusion 1-pin 12 is bored into the wafer mounting surface 5 of the wafer sample stage 4, as shown in FIGS. 3(a) and 3(b)! ° Is it stored loosely in the I through hole 14? ,
It was raining.

It was necessary to provide a large cavity 15 on the back of the sample table as an escape from the river.

Therefore, unevenness or variation occurs in the temperature distribution at each point on the sample stage. As a result, when an oxide film is deposited on a wafer, temperature conduction is different, which affects the uniformity of the deposited oxide film, resulting in uneven film thickness.

Moreover, this variation in temperature distribution also causes variation in the impurity concentration in the oxide film.

Another problem with the conventional protrusion 1-pin is that reactive gas enters between the through hole of the wafer sample stage and the protrusion 1-pin, and SiO and/or 5i0
2 flakes were generated. Bump 1 during wafer transport: Due to the fall of the bottle, flakes attached to the inner wall of the through-hole came into contact with the pin, scattering the flakes around, and increasing the amount of foreign matter [11] adhering to the wafer λ. In this way, when foreign matter adheres to the wafer, pinholes are generated in the film formation.

If these foreign substances adhere to the surface of the wafer and cause pinholes in the film formation, or if the film thickness or impurity concentration becomes unsuitable, the manufacturing yield of 11 conductor elements will be significantly lowered, and the throughput will also deteriorate. .

Foreign matter during wafer handling as described above (1'1)
・The problem is not limited to CV'l) thin film forming apparatuses, but also gas phase reaction apparatuses that use a reactor and a wafer sample stage, wafer protrusion 1, and pins as described above in the reactor, such as epitaxial apparatuses. , diffusion furnace, oxidation furnace.

Ion implantation device, great! Also recognized are the taring equipment, the steaming equipment, and the steaming equipment.

Therefore, an object of the present invention is to provide a wafer sample stage and a gas-phase reaction apparatus that eliminates problems such as generation of foreign matter, non-uniformity of film thickness, and non-uniformity of impurity concentration. The goal is to provide the following.

[L Stage for Solving the Problems] As a first stage for solving the above-mentioned problems and achieving the objects of the present invention, the present invention provides a reactor.

In a gas phase reaction apparatus having a wafer sample stand disposed in the furnace and a wafer fork for transporting the wafer to the wafer sample stand, a wafer mounting surface of the wafer sample stand has a -1 side facing toward one side. A through hole that opens is formed, and a wafer protrusion 1-means that can be moved in one direction is slidably inserted into the through hole, and the wafer protrusion 1-T' step has a hollow shape. The present invention provides a gas phase reactor characterized in that its upper end is connected to a vacuum evacuation stage.

[Function] As mentioned above, the wafer protrusion 1/stage in the gas phase reaction apparatus of the present invention is designed so that no gap is created in the 1"1 through hole drilled in the wafer sample stage (sliding). Further, this wafer protrusion 1'-1' stage is hollow, and its upper end is connected to the 1° air exhaust stage.

Therefore, unlike the conventional pin type, the wafer protrusion 1-stage of the present invention holds the wafer by 1[deg.] by empty suction.

Compared to the conventional force type in which the wafer is simply placed on the pin 1, the suction method of the present invention can strongly hold the wafer even if the suction pipe is small in diameter or only wood is used.

Therefore, the total volume of the through hole t'1 in the sample stage required for arranging the wafer protrusion 1-T' and the step can be made significantly smaller than in the case of the conventional pin method. Moreover, the sample stage
Since it is only necessary to open holes L″r1 at the locations, the negative effect on the uniformity and quality of the temperature distribution (1) can be minimized.

The most important feature of the wafer protrusion 1-L stage of the present invention is that it does not require a pin relief cavity unlike the conventional pin method. For this reason, the uniformity and quality of the temperature distribution on the wafer sample stage is affected by the trajectory. As a result, almost no unevenness in film thickness or variation in impurity concentration occurs.

Further, the wafer protrusion 1-P stage of the present invention is provided with a U? Since they are in contact with each other, the wafer protrusion It r = step and 1'■
There is no IIf ability for the reaction gas to enter the contact surface with the through hole and cause flakes to form and adhere there. Since the thrusting means is hollow, will flakes be generated on the inner hole wall? II) The possibility cannot be denied. However, when holding the wafer, 1
Since the suction is carried out once, even if flakes are attached to the wall surface of the inner hole, they will be pulled in the opposite direction, and there is no risk of dust generation or attachment to the wafer.

This may cause undesirable problems such as oxide flakes adhering to the wafer and causing pinholes in the film formation, or non-uniform film thickness and/or impurity concentration.
Not only can the production yield of conductor elements be improved, but also the throughput of the entire conductor production process can be improved.

[Embodiment Code] An embodiment of the present invention will now be described in detail with reference to the drawings.

FIG. 1(a) is a cross-sectional view of a wafer sample stage with a single stage of wafer protrusions used in the gas phase reaction apparatus of the present invention.
Figure (b) is a sectional view showing a state in which the wafer is lifted up at the wafer protrusion +tr and step 1-.

As shown in FIGS. 1(a) and 1(b), a 1" through hole reaches from the bottom surface of the wafer sample stage 4 made of stainless steel, Hastelloy, or other materials (e.g., ceramics). 20 is drilled in a single piece of wood approximately in the center of the sample stage.The end surface of the 1"r through hole 20 is approximately circular. Naturally, it is also possible to use an end face having a shape other than this.

Into this through hole 20 is inserted a wafer protrusion IT=step 30 consisting of a hollow vibrator, which has approximately the same shape as the water-shaped cross section of the 11 through holes and has an outer diameter approximately equal to the inner diameter of the rt communication hole. The diameter of the pipe may be 1 minute as long as it is necessary to adsorb the wafer. The diameter of the pipe can be readily determined by those skilled in the art. This pipe can be metal or ceramic! It can be configured from r1. Although not shown in Figure 1, the upper end of the pipe 30 is connected to a suitable vacuum evacuation device.

Although a vacuum pump (for example, a vacuum pump) can be used as the vacuum device, a one-field evacuation system can also be used. Therefore, other connections (eg, gols, hoses, etc.) can also be used to connect the upper end of the pipe 30 and these air devices.

The lower surface of the wafer sample stand supports this sample stand, and furthermore,
A hollow guide shaft 40 is fixedly installed to allow the pipe 30 to move smoothly in one direction.

The inner diameter of the guide shaft 40 is approximately the same as the inner diameter of the IT passage hole 20. This shaft is preferably constructed from a corrosion-resistant metal such as stainless steel.

Next, specific operations of the wafer protrusion 1-r and stage of the present invention will be explained.

When forming a thin film on a wafer, the pipe 30 is located at the surface of the sample stage. When the wafer 6 is discharged after the reaction is completed, the upper end of the pipe 30 is evacuated. The wafer is lifted from the sample stage surface along with the pipe 11 while being suctioned and fixed to one end surface of the pipe 30. When the pipe 30 reaches the set 1, limit position, the pipe 30 moves 1°, shi, l: I.

Thereafter, the wafer transport lever 7 is inserted between the wafer and the sample stage. When the fork is fully inserted, pipe 30
starts the downward movement. At the same time, 1゛[emptiness υl Qi is stopped +l. Thus, the wafer is transferred to transport fork 1- and carried out of the reactor.

When carrying a wafer into the reactor, the wafer can be charged onto the surface of the sample stage by performing the reverse operation to the above-described operation.

The diameter of the suction pipe in contact with the wafer is small, so the area in contact with the wafer is small. Therefore, since the volume of the space 11 as in the conventional case is naturally reduced, the influence of heat conduction to the wafer is reduced, and the effect of minimizing the influence of thin film unevenness can be obtained.

[Effects of the Invention Part 1] As explained above, the wafer stage 1 in the gas phase reaction apparatus of the present invention is a JT drilled in the wafer sample stage.
There is no gap in the through hole, and the sliding capacity is 11.
There is one person. Moreover, this wafer! - The L stage is hollow and its upper end is connected to the 1" empty exhaust stage.

Therefore, unlike the conventional pin type, the wafer protrusion 1-L stage of the present invention holds the wafer by the 1°L air suction 7t.

Compared to the conventional method in which the wafer is simply placed on one of the pins, the suction method of the present invention can strongly hold the wafer even with a small-diameter suction pipe or a piece of wood.

Therefore, the v
The total volume of the I-holes can be significantly smaller than in the case of conventional pin systems. Moreover, since it is only necessary to provide vI through holes at certain points on the sample stage, the uniformity of temperature distribution can be improved.
, the negative effects caused by this are minimized.

The most important feature of the wafer punching stage of the present invention is that it does not require a pin escape cavity unlike the conventional pin method.

For this reason, the uniformity and quality of the temperature distribution on the wafer sample stage is dramatically improved. As a result, film thickness unevenness or impurity centers J
Variations of 1 will almost never occur.

In addition, since the wafer protrusion 1-1 of the present invention is in sliding contact with the IT through hole in the sample stage, the reaction gas may enter the contact surface between the wafer protrusion 1, 1 and the IT through hole. There is no possibility of causing flakes to form. Thrust 1/Gecho.

Since the step is hollow, flakes are generated and adhered to the inner hole wall surface.
I can't deny the performance. However, when holding the wafer, vacuum suction is performed at 1°, so even if there are flakes attached to the inner hole wall, they will be pulled in the opposite direction, and there is no risk of dust generation or attachment to the wafer. .

(This may result in oxide flakes adhering to the wafer, causing pinholes in the film formation, or non-uniform film thickness and/or impurity concentration.)
It is possible to reduce the occurrence of
Not only can the manufacturing capacity of the conductor be increased by one unit, but the overall throughput can also be increased by one unit.

[Brief explanation of the drawing]

FIG. 1(a) is a cross-sectional view of a wafer sample stage with wafer protrusions 1 and 1 used in the gas phase reaction apparatus of the present invention, and FIG. Fig. 2 is a schematic cross-sectional view of a conventional CV l) device, and Fig. 3 (a) is a +1 side view of the wafer sample stage. 3(b) is a partial sectional view taken along line bb. l...Reactor, 2...Buffer, 3...Cover. 4... Wafer sample stand, 6... Wafer, 7... Wafer fork, 8... Reaction gas feed pipe, 9... Wafer sample stand support t, y TX stage, 10... Heating 1 step, 11・
・Gate part. 12...Wafer hit! - Pin, 15...Cavity, 20.
...it through hole, 30...wafer protrusion 1-to step, 40.
・Guide shaft

Claims (3)

[Claims] (1) In a gas phase reactor having a reactor, a wafer sample stand disposed in the reactor, and a wafer fork for transporting the wafer to the wafer sample stand, the wafer mounting surface of the wafer sample stand is A through hole opening upward is formed, and a wafer ejection means that can move up and down is slidably inserted into the through hole, and the wafer ejection means is hollow and A gas phase reactor characterized in that a lower end is connected to a vacuum evacuation means. (2) The gas phase reaction apparatus according to claim 1, wherein only one wafer lifting means is inserted approximately at the center of the wafer sample stage. (3) A hollow shaft is disposed on the lower surface of the wafer sample stand to support the sample stand and further to smooth the vertical movement of the hollow wafer lifting means. The gas phase reactor described in .