JPH01133320A - Thin-film processing device - Google Patents

Abstract

PURPOSE:To make the space of a reaction room small and to save energy and be more uniform by setting the distance between axes of each stage provided with a plurality of holders for mounting work to be processed shorter than the circumscribed circle diameter of a plurality of holders and by making a stage rotate so that neighboring holders of a stage will not interfere with each other. CONSTITUTION:Axes 35A and 35B are mounted in the center of the lower surface of stages 32A and 32B, each rotating with respective stage. The distance between axes 35A and 35B is set shorter than the circumscribed circle diameter of a plurality of holders 34 mounted in a stage 32A or 32B. And when neighboring stages 32A and 32B rotate in opposite directions, an adjacent holder 34 is positioned between circumference directions of each. Thus, while each set adjacent to the holder 34 on the stages 32A and 32B revolves while turning on its own axis, it moves in a reaction room 1a by the rotation of a table 30. This enables the degree of processing between each work to be processed 7 and within each work to be processed 7 to be uniform despite the difference of thin-film processing capabilities in the circumferential and radial directions of the electrode 3.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention relates to an apparatus that performs thin film processing such as film formation and etching on a substrate such as a semiconductor (hereinafter referred to as a processing object). In particular, it relates to improving uniformity of processing.

(Prior Art) For example, as a film forming apparatus, a parallel plate type plasma CVD apparatus as shown in Fig. @5 and Fig. @6 is known.
The table 4 is rotated by a drive source 5. There is a holder 6 on the table 4 as shown in the 8g6 figure.
A workpiece 7 such as a wafer is placed on top of the workpiece 7, and the workpiece 7 is heated by a heat source such as a heater 3a embedded in the electrode a, and the workpiece 7 is exhausted from an exhaust port 8. A reaction gas is introduced from the nozzle 9 while maintaining the inside of the reaction chamber 1a at a predetermined degree of vacuum, and a high frequency voltage is applied to the electrode 3 to generate a plasma discharge between the electrode 3 and the table 4.
Form a thin film on top.

Further, as shown in FIGS. 7 and 8, the holding body 6a
f A gear 11 is rotatably mounted on the concentric circumference of the table 4 and fixed to a shaft 10 extending downward from the holder 6a.
There is also one in which the holder 6a f rotates and revolves around its axis as the table 4 rotates by meshing with a ring gear 12 fixed to the bottom surface of the vacuum reaction vessel 1, thereby improving the uniformity of the film thickness.

(Problems to be Solved by the Invention) In the above-mentioned thin film processing apparatus, it is desired to improve productivity by increasing the number of batches processed. However, when trying to store a large number of workpieces 7 in the same table 4, one
If the workpieces 7 are placed in two rows, the productivity is poor (but it is possible to place them in two rows, inside and outside, and this is actually done in semiconductor processing equipment such as vapor phase growth equipment. However, as the diameter of the workpiece 7 increases, Due to this, it may not be possible to achieve uniformity by simply placing them in two rows.For example, the inventors of the present application have developed a plasma CVD apparatus in which the inner and outer rows are held as shown in FIGS. 9 and 10. An attempt was made to form a film using a prototype device in which the bodies 6a, 6a both rotate and revolve around their own axis using a ring gear 13 having teeth inside and outside.The results were as shown in Figure 1@11.
The uniformity of each of the inner and outer rows is due to the effect of rotation and revolution, and shows high uniformity, with the uniformity in the outer workpiece 7 being ±3.2% and that in the inner row being ±0.9%. Ta. However, there was a very large difference of ±32.5% between the inner and outer objects to be treated.

In the case of plasma CVD equipment, the factors that affect film formation include the degree of vacuum, R and F applied power, temperature, distance between electrodes, nozzle position and shape, etc., and film formation tests were conducted under various conditions. However, it was not possible to obtain conditions with excellent internal and external uniformity. In addition, in the case of plasma CVD equipment, the thickness of the vacuum reaction vessel 1, the diameter of the table 4, and the placement position of the workpiece 7 are said to have an influence on the plasma density distribution, and thus on the film thickness distribution. When designing the device, there is an unknown factor in that it is not certain whether the film thickness distribution can be reliably made uniform, making it even more difficult to increase the diameter.

Note that FIG. 12 shows the table of the workpieces 7 in the inner and outer rows of the prototype machine shown in FIGS. 9 and 10, when only the table 4 is rotated without rotating the holders 6a and 5a. The film thickness in the radial direction was measured and plotted.

As is clear from FIG. 12, in the plasma CVD apparatus described above, the film thickness distribution in the radial direction is approximately s.
It changes greatly with the in curve. Such a change in thin film processing efficiency in the radial direction is a phenomenon that is observed not only in plasma CVD apparatuses but also in various thin film processing apparatuses, although there may be differences in degree.

In addition, in a CVD apparatus that does not use plasma, the 13th
As shown in the figure, a fixed internal gear 21 is placed in a reactor 20, a sun gear 22 is provided at the center of the fixed internal gear 21, and both gears 21
, 22 are provided, a plurality of objects 7 to be treated are placed on each of the holders 23, and the sun gear 22 is rotated to cause the holders 23 to revolve around themselves and to make the film thickness uniform. It is also known that there is a method for
. However, in this method, the holder 23 of the workpiece 7
Since the passage points in the reactor 20 are different between the part near the outer periphery and the part near the center, even if uniformity can be achieved between each workpiece 7, uniformity within the workpiece 7 cannot be sufficiently achieved. It has disadvantages that cannot be avoided. This drawback becomes more noticeable as the diameter of the object 7 to be processed increases.

SUMMARY OF THE INVENTION An object of the present invention is to provide a thin film processing apparatus that can uniformly perform thin film processing on a larger number of large-diameter objects within and between each object.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides an apparatus for performing thin film treatment on a workpiece in a reaction chamber equipped with all reaction gas inlets and exhaust ports.
A table rotatably installed in the reaction chamber, a plurality of stages rotatably installed on the concentric circumference of this table, and a workpiece placed rotatably installed on the concentric circumference of the stage. a plurality of holding bodies, and a drive mechanism that rotates the table, stage, and holding bodies,
The distance between the axes of the stages is set to be shorter than the diameter of the circumscribed circle of the plurality of holders provided on each stage.

(Function) The holder rotates on its own axis and revolves around the rotation of the stage, and is moved within the reaction chamber by the rotation of the stage and table. Since the holding body is also rotating, each part of the object to be treated is also placed under almost the same conditions in the radial direction. Therefore, the uniformity of processing between and within the objects to be processed is achieved more completely, and the distance between the axes of the stage is determined as described above, and the holders are arranged more densely. By reducing the space of the reaction chamber, energy savings and higher uniformity can be achieved.

(Embodiment) Hereinafter, a description will be given of FIGS. 1 to 3 showing an embodiment in which the present invention is applied to a parallel plate type plasma CVD apparatus.

Note that the same parts as those in FIG. 4 described above are designated by the same reference numerals, and the description thereof will be omitted. 30 is a disc-shaped table entirely composed of a ground electrode facing the electrode 3, and is rotated by a drive source 5.

On the concentric circumference of the table 30, an even number of stages 32A and 32B are rotatably and alternately mounted via bearings 31. A plurality of holders 34 are attached via bearings 33 on the concentric circumferences of the stages 32A and 32B.

Shafts 35A and 35B, which rotate together with the stages 32A and 32B, are attached to the centers of the surfaces of the stages 32A and 32B, respectively. A thick gear 36A and a thin gear 36B are attached to the lower ends of the shafts 35A and 35B in FIG. 1, respectively. The thick gear 36A is a central gear 37 fixed to the bottom of the vacuum reaction vessel 1 concentrically with the table 30.
They are engaged. On the other hand, the thin gear 36B is located above the center gear 37 and does not mesh with it, but meshes with the thick gear 36A.

One stage 32A or +! in the distance between the axes 35A and 35B. It is set shorter than the diameter of the circumscribed circle of the plurality of holders 34 attached to 32B.

The positional relationship of each holder for each stage 3'2A and 32B is as shown in FIG.
When A and 32B rotate in opposite directions, the adjacent holders 34 are positioned between them in the circumferential direction.

Further, gears 39 are fixed to the lower ends of the support shafts 38 supporting the holder 34 in FIG. 1, respectively. These gears 39 are positioned concentrically with the shafts 35A and 35B and mesh with internal gears 40 fixed to the table 3().

Next, we will explain the function of the wooden table. The holder 34 and the object to be processed 7 are heated by the heating source 3a, the reaction chamber 1a is kept at a predetermined degree of vacuum by being evacuated from the exhaust port 8, the reaction gas is introduced from the nozzle 9, and high-frequency power is applied to the electrode 3. Applying voltage to the same electrode 3 and table 30 as well as this table 30
stages 32A and 32B that are electrically connected to
Plasma discharge is generated between the holder 34 and the holder 34, and a thin film is formed on the object 7 to be processed.

At this time, the drive source 5 rotates the table 30 at a relatively low speed. Now, if table 30i is rotated in the direction shown by arrow A in Figure 2, center gear 3
Thick gear 36A meshing with 7 &! The stage 32A' rotates in the direction shown by arrow B in FIG. 2 and is connected thereto! i-Same (rotate in the direction of arrow B).

Due to this rotation of the stage 32A, the support @:38 of the holder 34 attached to the shaft rotates in the direction of arrow B, and the gear 39 meshing with the internal gear 40 rotates.
and the holder 34 connected thereto are rotated in the direction of arrow C.

On the other hand, a thin gear 36B meshes with a thick gear 36A.
&'! It rotates in the direction of the arrow opposite to the arrow B.

Therefore, the stage 32 connected to the thin gear 36B
B also rotates in the direction indicated by the arrow, and the holding body 34 above it rotates in the direction indicated by the arrow E.
Rotate in the direction.

Therefore, each set of adjacent holders 34 on the stages 32A and 32B rotates in opposite directions and moves within the reaction chamber la by the rotation of the table 30.

Therefore, each holder 34 moves within the warp chamber la in the circumferential direction and moves in the same range in the radial direction, and the holder 34 rotates, so the object to be processed on the holder 34 Each part above also moves in the same range. Therefore, even if there is a difference in thin film processing capacity in the circumferential direction and the radial direction of the electrode 3, the seven objects to be processed and the degree of processing within each object to be processed 7 are made uniform.

FIG. 3 shows the film thickness distribution when a silicon nitride film is formed on a silicon wafer (object to be treated) using the apparatus of this example, and the horizontal axis shows the radius of the hemorrhoid treatment object 7. The directional position and the film thickness are shown on the vertical axis, and one stage 32A! These are the measurement results for three objects to be processed 7 in 32B or 32B. According to this, the uniformity within the object 7 to be processed was within ±1%, and the uniformity between the objects 7 to be processed was within ±3%, which was a very high level of uniformity. Note that the film forming conditions in the above examples are shown below.

Diameter of table 30: 800+Mn Number of sheets processed/batch = 18 sheets Diameter of circumscribed circle of holder 34 = 280Wr! R table rotation speed: 7 r, p, m.

Distance between electrode 3 and workpiece 7 = 40 Temperature of distribution electrode 3 = 350°C Frequency of high frequency power source 2: 13.56 MHz Output power of high frequency power source 2 200 W Degree of vacuum: 0.3 Torr Gas used and flow rate: SiH4, 50SCCM, N
H3, 300SCCM FIG. 4 shows another embodiment of the present invention, in which a holder 3 is mounted on each stage 41A and 41B.
4, two of each.

Although the above-mentioned embodiment shows an example in which the present invention is applied to a plasma CVD apparatus, the present invention can also be applied to other thin film processing apparatuses such as film forming apparatuses and etching apparatuses. Furthermore, in the embodiments described above, stages 32A, 32B, or 41
A, 41B and the holding body 34 are rotated in opposite directions as shown by arrows B and C in FIG. 2 or 4, but it is not possible to rotate both in the same direction. This is more effective for uniformity, and for this reason, the internal gear 40 and gear 3
It is recommended to add an idle gear (not shown) between 9 and 9. Furthermore, to improve uniformity, stage 32A,
It is preferable that the rotation ratio between 32B and the holding body 34 is not an integral multiple.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to improve the uniformity of thin film processing within each workpiece and between workpieces, to process a larger number of workpieces, and to take up less space in the reaction chamber. can be made smaller, resulting in energy savings and higher uniformity.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing one embodiment of the present invention, and Fig. 2 is a sectional view showing an 81
FIG. 3 is a diagram showing all the film formation results according to one embodiment of the present invention, and FIG. 4 is a partially fractured sectional diagram showing another embodiment of the present invention. , FIG. 5 is a sectional view of a conventional device, FIG. 6 is a sectional view taken along the VT-VIX line in FIG. 5, FIG. 7 is a sectional view of another conventional device, and FIG. 8 is a sectional view taken along the line 9 is a sectional view of the reference device, FIG. 10 is a sectional view taken along the line X-X in FIG. 9, and FIG. 11 is a diagram showing the film formation results using the reference device shown in FIGS. FIG. 12 is a diagram showing the film formation results when the object to be processed is not rotated using the reference apparatus shown in FIGS. 9 and 10, and FIG. 13 is a cross-sectional plan view showing still another conventional apparatus. 1a... Reaction chamber, 5... Drive source,
7...Object to be processed, 8...Exhaust port,
9... Nozzle, 30... Table,
32A, 32B, 41A, 41B...
...stage, 34...holding body, 35A
, 35B... shaft, 36A, 36B
, 39...gear, 37...center gear, 40...internal gear.

Claims (1)

[Scope of Claims] 1. In an apparatus for performing thin film treatment on an object to be treated in a reaction chamber equipped with a reaction gas inlet and an exhaust port, a table rotatably provided in the reaction chamber and a A plurality of stages rotatably provided on concentric circles,
A plurality of holders for placing objects to be processed are rotatably provided on the concentric circumference of the stage, and a drive mechanism that rotates the table, the stage, and the holder, and an axis between the axes of the stage is provided. The distance is set to be shorter than the diameter of the circumscribed circle of the plurality of holders provided on each stage, and further, the holders on adjacent stages are arranged so as not to interfere with each other, and the holders are arranged so as not to interfere with each other. A thin film processing apparatus characterized in that the stage is configured to be rotated. 2. The thin film processing apparatus according to claim 1, wherein adjacent stages are configured to be rotated at the same rotation speed in opposite directions.