JPS63293165A - Equipment for treatment - Google Patents

Abstract

PURPOSE:To prevent generation of an inappropriate reaction product and to prevent adhesion and deposition of a foreign matter near a gas head by producing a multipipe structure, the gas head of which blows a plural kinds of gas, and blowing each gas while concentrically turning. CONSTITUTION:The gas head 20 having the multiple structure which is set on the top of a bell jar 3, is concentrically installed over an apex of a buffer 4. In that structure, a 1st nozzle 21 of the outside is superposed on a 2nd nozzle 31 of the inside in its gas blowing direction. The different kind treating gases are supplied to both nozzles 21 and 31 and are blown toward the buffer 4 respectively as a concentrical stream. The treating gases supplied flow down along a conical surface of the buffer 4 uniformly in the circumferential direction, and are uniformly brought into contact with a wafer group 9 being turned round at its lower end circumferential surface and are discharged from a discharging outlet 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a processing technology, in particular a processing technology in which processing is performed using a head that blows out a plurality of p1!1 gases, for example, in the manufacturing process of semiconductor devices. , Cv on the wafer
The present invention relates to what is effective when used in the rotation-revolution type CVD technology that generates DIl.

[Conventional technology]

In the manufacturing process of semiconductor devices, CvDIl is deposited on the wafer.
! A CVD apparatus for generating , a processing chamber, a substantially triangular pyramid-shaped buffer arranged in the processing chamber, a heater cover arranged to revolve around the bottom of the buffer,
It is equipped with a plurality of susceptors that are arranged to rotate within a plurality of window holes formed in the heater cover, and a gas head that is arranged on the top of the buffer and blows out a plurality of types of processing gas. Ueno 1 as a processing object is housed in the wafer and rotated around its axis, while multiple types of processing gases can be simultaneously blown out from the gas head.
Some devices are configured to perform desired film formation processing through reaction.

An example that describes CVD technology is "Electronic Materials November 1985 Special Edition" published by Kogyo Research Association Co., Ltd., November 20, 1985, pages 53 to 54.

[Problem that the invention seeks to solve]

In such a rotation-revolution type CVD apparatus, the processing gases are blown out from the gas head and come into contact with each other at the same time, causing them to react with each other with uneven concentration distribution in the circumferential direction, resulting in unevenness on the surface of the head. The inventor of the present invention has revealed that there is a problem in that foreign substances such as proper reaction products are attached.

An object of the present invention is to provide a processing technique that can suppress adhesion of foreign matter.

The above and other objects and novel features of the present invention are accomplished by the present invention! It will become clear from the description and accompanying drawings.

[Means for solving problems]

An overview of typical inventions disclosed in this application is as follows.

That is, a gas head having a plurality of nozzles that blow out different gases is configured in a multi-tube structure, and each of the nozzles is configured so that the gas can be spun concentrically to blow out the gas.

[Effect]

According to the above-described means, since the gas is swirled and blown out from each nozzle, the concentration distribution of the gas blown out from each nozzle in the circumferential direction becomes uniform. Therefore, each gas comes into proper contact with each other at a preset ratio around the entire circumference of the gas head, so that the desired reaction set by controlling the supply (flow rate, flow rate) of each gas can be achieved all around the circumference. will occur fairly and evenly. As a result, generation and adhesion of inappropriate reaction products near the head are suppressed.

〔Example〕

Fig. 1 is a vertical cross-sectional view showing a rotation-revolution type CVD apparatus which is an embodiment of the present invention, Fig. 2 is an enlarged partial longitudinal cross-sectional view showing the gas head thereof, and Fig. 3 is taken along line m-m in Fig. 2. FIG. 4 is a plan sectional view taken along line IV-rV in FIG. 2, and FIG. 5 is an enlarged partial sectional view for explaining the function.

In this embodiment, this CVD apparatus is equipped with a chamber 1 having an exhaust port 2 at its lower part, and a bell jar 3 formed in the shape of a substantially triangular pyramid cylinder with an opening at the bottom is suspended at the upper part of the chamber 1. held.

A gas head (described later) that blows out multiple types of processing gases is installed at the top of the bell jar 3.
Buffers 4 are arranged concentrically within. The buffer 4 is formed into a substantially conical shape that is smaller than the bell jar 3 by a predetermined size and has a concave curved surface.

On the other hand, a turntable 5 is supported horizontally in the lower part of the chamber 1, and the turntable 5 is configured to be rotated by a rotation drive device 6 including a motor, a speed reduction mechanism, and the like. A plurality of rotating shafts 7 are provided on the turntable 5.
are arranged at approximately equal intervals in the circumferential direction on the outer periphery and are each supported approximately vertically, and each rotating shaft 7 is configured to be rotated by a rotation drive device 8 consisting of a motor, a speed reduction mechanism, etc. There is. Susceptors 10 for supporting wafers 9 as objects to be processed are horizontally supported on each rotation shaft 7, and these susceptors 10 are arranged to revolve around the lower end of the buffer 4 while rotating on their own axis. It is located in

The susceptor 10 is made of quartz glass or the like and has a disk shape with a diameter larger than that of the wafer 9, and its upper surface, which is a wafer support surface, is formed into a flat surface.

On the upper surface of the susceptor 10, a plurality of protrusions 11 formed in a substantially cylindrical shape with rounded ends are arranged so as to position the wafer 9 concentrically, and protrude integrally with the susceptor 10. , each protrusion 11 has a height equal to that of the wafer 9
The pitch in the circumferential direction is set to be smaller than the width of the four orientation flats on the wafer 9.

Heaters 12 are disposed below the susceptor lO, and these heaters 12 are connected to the wafer 9 supported by the susceptor lO.
It is constructed so that it can be heated respectively. A heater cover 13 is disposed on the lower end of the buffer 4 and is supported via a plurality of pillars 14 erected on the turntable 5 .

Further, a plurality of window holes 15 are formed in the heater cover 13, each having a size that can accommodate the susceptor 10, and a chamfered portion is formed in the opening edge of each window hole 15 in a convex curved shape. . A susceptor 10 is loosely fitted into each window hole 15 so as to be surrounded by a heater cover 13. As a result, the heater cover 13 is disposed below the susceptor 10 and covers the heater 12, thereby effectively performing heating. I'm trying to make it happen.

The gas head 20 disposed at the top of the bell jar 3 includes a first nozzle 21 and a second nozzle 31.
As shown in the figure, it has a double pipe structure and is installed concentrically on the top of the buffer 4.

The first nozzle 21 has a main body 22 formed in a cylindrical shape with a minimum diameter, and the hollow part of this nozzle main body 22 has one end (hereinafter referred to as the lower end), an opening serving as an air outlet 23, and a middle part supplying air. A flange portion 25 formed in a disk shape is provided at the upper end of the main body 22 substantially forming the passages 24.
are disposed perpendicularly and concentrically to the center and protrude integrally, and as shown in FIG. It is located at the top of the tower, and is opened so as to communicate with the upper end. This inlet 26 is adapted to be connected to a first process gas source (not shown) that supplies a process gas such as monosilane or phosphine.

The second nozzle 31 includes a nozzle body 32 formed in a cylindrical shape with a larger diameter than the first nozzle body 22.
The nozzle 31 is disposed on the outside of the first nozzle 21 so that the centers of both main bodies coincide with each other. Second nozzle body 32
The hollow part is connected to the first nozzle body 22, and the lower end opening substantially defines a circular ring-shaped outlet 33 surrounding the first nozzle outlet 23, and the middle part thereof substantially defines a hollow cylindrical supply passage 34. is forming. At the upper end of the second nozzle main body 32, a flange portion 35 formed in a substantially disk shape is arranged concentrically and at right angles to the center and integrally protrudes. A gas reservoir 37 is arranged concentrically and perpendicularly to the center of the center, and is opened in a substantially disk-shaped hollow space. As shown in FIG. 4, a gas introduction passage 36 is provided in the flange portion 35 so as to be arranged in the tangential direction of the gas reservoir 37 and communicate with the inside of the gas reservoir 37. It is connected to a supply source (not shown) for supplying oxygen gas as the other processing gas. A fitting hole 38 is concentrically formed in the upper end of the flange portion 35, and a first
By fitting the nozzle body 21 from above, the second
The nozzle 31 is arranged concentrically with the first nozzle 21 and stacked on the lower side. In this stacked state, the first
The lower surface of the flange portion 25 of the nozzle 21 and the upper surface of the flange portion 35 of the second nozzle 31 are joined, and a seal ring 39 is sandwiched between the rejoined surfaces.

Next, the effect will be explained.

The wafer 9 to be processed is placed on the protrusion 1 on each susceptor 1G.
．． They are each supported in a placed state so as to be positioned by one group. The wafer 9 supported by the susceptor io is heated by the heater 12.

At this time, since the heater 12 is covered by the heater cover 13, heating is performed effectively and heat radiation to the space above the heater cover 13 is prevented.

When the wafer 9 is set, the susceptor 10 is rotated around the buffer 4 by the turntable 5 and the rotating shaft 7 within the window hole 15 in the heater cover 13 .

During this rotation, processing gases such as monosilane gas or phosphine gas and oxygen gas form concentric swirling flows from the first and second nozzles 21.31 of the gas head 20 toward the buffer 4, respectively. Supplied.

The supplied processing gas flows down evenly in the circumferential direction along the conical surface of the buffer 4, and after evenly contacting each of the 9 groups of wafers rotating around its lower end,
The air is exhausted from the exhaust port 2.

A desired CVD film is generated on the wafer 9 by a CVD reaction when the processing gas comes into contact with the wafer 9 . At this time, since the wafer 9 is rotating around its own axis, the wafer 9 faces the gas flow equally in all directions, and as a result,
The film forming process using the gas is uniformly performed over the entire circumference of the wafer 9.

By the way, if monosilane gas or phosphine gas and M gas come into contact with each other at an inappropriate mixing ratio immediately after they are blown out from the gas head, an inappropriate CVD reaction will occur, so the gas head will be exposed to inappropriate reaction products. may adhere and accumulate as foreign matter. If this foreign material detaches from the gas head and adheres to the wafer,
The surface of the head needs to be cleaned regularly because manufacturing yield is reduced.

Here, as shown in FIG. 5, the gas introduction path 26A
is connected to the gas supply passage 24A on the normal line exiting from the center of the supply passage, the gas introduced into the supply passage 26A from the introduction passage 26A is perpendicular to the inner circumferential surface of the supply passage 26. As a result, the gas flow becomes a steady flow with a waveform as shown by the waveform line in FIG.

When this steady flow of gas is blown out from the outlet 23A, the concentration distribution of the gas becomes non-uniform in the circumferential direction.
For example, the gas concentration in the circumferential direction is higher at the mountain side of the steady flow, and lower at the valley side. If the gas concentration in the circumferential direction becomes non-uniform in this way, the gases will be mixed at an inappropriate ratio, resulting in foreign matter adhering to the gas head. Particularly, when there is a partial shortage of oxygen gas, foreign matter tends to adhere to the surface, and when there is a partial shortage of oxygen gas on the male side of the buffer, the gas stagnates, causing foreign matter to stick to the surface. The inventor of the present invention has found that there is a problem in that there is a tendency for the adhesive to adhere to the surface.

However, in this embodiment, the flow of monosilane gas or phosphine gas blown out from the first nozzle 21,
In addition, since the flow of oxygen gas blown out from the second nozzle 31 is generated into a swirling flow, the gas concentration distribution in the circumferential direction is uniform over the entire circumference, so that the oxygen gas flows from the first nozzle 21 to the swirling flow. The gas blown out in a swirling flow and the gas blown out in a swirling flow from the second nozzle 31 are mixed at a predetermined ratio over the entire circumference of the gas head 20, and a predetermined CVD The reaction occurs evenly and properly over the entire circumference, and inappropriate reaction products are removed as foreign matter from the gas head 2.
0 and will not be deposited.

That is, the gas introduced from the introduction path 26 into the supply path 24 in the tangential direction in the first nozzle 21 flows through the supply path 24.
By flowing along the inner circumferential surface of the air, a swirling flow is generated. The gas flows down due to its own weight, but since it is a swirling flow, it flows down in a spiral shape and is blown out from the outlet 23. At this time, the swirling flow and spiral flow are such that the gas is continuously introduced. Since the gas is continuously generated by being introduced into the gas, the concentration distribution of the gas in the circumferential direction becomes uniform over the entire circumference.

Further, in the second nozzle 31, the gas reservoir 3 is
The oxygen gas introduced tangentially into gas reservoir 37
A swirling flow is generated by flowing along the inner circumferential surface of the fluid. The gas flows down into the supply channel 34 due to its own weight, but it flows down in a spiral shape and reaches the outlet 3.
At this time, since the gas reservoir 37 is formed in the second nozzle 31, the gas introduced through the introduction path 36 temporarily stagnates in the gas reservoir 37, and then flows into the supply path 34.
Since the spiral flow is continuously generated at the outlet 33, the gas concentration distribution in the circumferential direction becomes uniform over the entire circumference.

In this way, the first nozzle 21 and the second nozzle 31
If the concentration distribution of the gases blown out from each is uniform over the entire circumference, both gases will be mixed at a uniform ratio over the entire circumference.

Then, when the gas supply to the gas introduction paths 26 and 36 is controlled to be a preset value,
The mixing ratio of both gases on the lower surface of the gas spatula 20 is uniform over the entire circumference and has a predetermined value. Therefore, since the CVD reaction by both gases occurs uniformly and properly over the entire circumference, inappropriate reaction products do not adhere to the gas head 20 as foreign matter.

In addition, since both gases, which have become spiral flows, flow down equally over the entire circumference of the conical surface of the buffer 4, the CVD reaction occurs uniformly and appropriately even in the middle and lower end of the conical surface of the buffer 4. Foreign matter will not adhere to the conical surface or the like.

According to the embodiment described above, the following effects can be obtained.

(1) By swirling the gas concentrically and blowing it out from each nozzle, each gas can be brought into contact with each other at a uniform ratio in the entire circumferential direction.
It is possible to prevent inappropriate reaction products from being generated, and it is also possible to prevent foreign matter from adhering and accumulating on the surface near the gas head, the male surface of the buffer, and the like.

(2) By preventing get from adhering to the vicinity of the gas head, it is possible to avoid contamination of the wafer due to detached foreign matter, thereby improving manufacturing yield and product quality and reliability. can.

c':A In addition, by preventing foreign matter from adhering to the gas head and male buffer surface, cleaning work inside the processing chamber can be omitted or reduced, increasing the operating rate of the equipment. Productivity can be improved.

(4) By configuring multiple nozzles concentrically, with the outer nozzles overlapping the inner ones in the gas blowing direction to form a multi-tube structure, the inner nozzles can be stacked sequentially from the outer nozzle. Since it is possible to construct a head with a multi-tube structure, manufacturing of the head can be simplified.

(5) In order to configure the gas flow to flow uniformly over the entire circumference without swirling the gas flow, the gas supply at the nozzle is necessary to prevent the generation of a steady waveform flow as shown in No. 5110. Although it is necessary to set the passage etc. to a large diameter, by configuring the gas flow to swirl as in the above embodiment, it is possible to avoid increasing the diameter of the nozzle.
Since the gas concentration distribution can be made uniform over the entire circumference, it is possible to promote the adoption of a multi-tube structure.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the Examples and can be modified in various ways without departing from the gist thereof. Nor.

For example, the means for swirling the gas is not limited to a structure in which the gas introduction paths are connected tangentially, but also a structure in which the gas introduction paths are connected at an appropriate angle with respect to the normal line, A structure in which guide vanes are provided protruding from the supply path may also be used.

Further, it is preferable that the swirling direction of each gas is selected to be the same direction or opposite directions for adjacent gases, depending on various conditions.

The head is not limited to a double tube structure, but also a triple tube structure or a 4! Other multi-tubular structures may also be formed, such as tubular structures and the like.

The gas reservoir can be omitted when a plurality of gas introduction passages are provided in the circumferential direction.

In the above explanation, the invention made by the present inventor was mainly explained in the case where it was applied to the rotation-revolution type CVD apparatus, which is the field of application that was the background of the invention, but it is not limited to this, and other CVD apparatuses, Oxide film forming equipment,
The present invention can be applied to diffusion devices, dry etching devices, etc. The present invention can be applied to at least all processing devices that use processing gas.

〔Effect of the invention〕

A brief explanation of the effects obtained by typical inventions disclosed in this application is as follows.

By concentrically swirling the processing gases and blowing them out from multiple concentrically arranged nozzles, each processing gas can be brought into contact with a uniform ratio in the entire circumferential direction, thereby preventing inappropriate reaction products. In addition, it is possible to prevent foreign matter from adhering and accumulating on the surface near the gas head.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view showing a rotational-revolution type CVD apparatus which is an embodiment of the present invention, Fig. 2 is an enlarged y1 cross-sectional view showing the gas head, and Fig. 3
The drawings are a plan sectional view taken along the line ■-■ in FIG. 2, FIG. 4 is a plan sectional view taken along the line rV-IV in FIG. 2, and FIG. 5 is an enlarged partial sectional view for explaining the operation. ■...Chamber, 2...Exhaust port, 3...Belljar, 4...Buffer, 5...Turntable, 6.8
... Rotation drive device, 7 ... Rotation shaft, 9 ... Wafer (workpiece), IO ... Susceptor, 11 ... Protrusion,
12... Heater, 13... Heater cover, 14...
・Post, 15...Window hole, 20...Cus head, 21
...First nozzle, 31...Second nozzle, 22.32
... Nozzle body, 23.33 ... Air outlet, 24.3
4... Supply path, 25.35... Flange portion, 26.
36... Gas introduction path, 37... Gas reservoir, 38...
Fitting hole, 39...Seal ring.

Claims (1)

[Claims] 1. The gas head is equipped with a gas head that blows out multiple types of gas, and this gas head has a plurality of nozzles arranged in a concentric circle, and the outer nozzle is overlapped with the inner one in the gas blowing direction. 1. A processing device characterized in that it has a tube structure, and each nozzle is configured to swirl gas concentrically and blow it out. 2. The processing apparatus according to claim 1, wherein the gas introduction path is connected to the nozzle so as to be inclined with respect to the normal line of the center of the nozzle as means for swirling the gas. 3. The processing apparatus according to claim 1, wherein each of the nozzles is provided with a gas reservoir. 4. The processing apparatus according to claim 1, wherein each of the nozzles is configured such that the gas blown out from the nozzles swirls in the same direction. 5. The processing apparatus according to claim 1, wherein each of the nozzles is configured such that the swirling directions of the gas blown out from the nozzles are opposite to each other.