JPS59224128A - Plasma treating device - Google Patents

Abstract

PURPOSE:To make the uniformity of film thickness and film quality and mass production compatible with each other by cylindrically constituting a wafer holder and arranging a large number of wafers to be treated along the inner wall surface of the holder. CONSTITUTION:A large number of wafers are arranged to the inner wall surface of a holder 14, and SiH4 gas is fed between a shielding cylinder 12 and the inner wall surface of the holder from a lower section. The holder 14 can be turned while the wafers 16 are fitted to the inside. Not only the number of the wafers charged can be made sharply larger than conventional devices but also the uniformity of film thickness and film qualty is excellent even in one wafer or among a plurality of the wafers.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an improved plasma processing (chemical vapor phase reaction) apparatus that can effectively form deposited films with uniform thickness and quality on the surfaces of a large number of objects to be processed. etc.

Conventionally, several types of plasma CVD apparatuses have been proposed, but in all of these apparatuses, a plasma-CVD reaction is performed with an object to be processed, such as a wafer, placed on a flat holder surface. A deposited film is formed on the surface of the object to be processed. Such a device.

Since the number of objects that can be treated at one time is limited to a low number,
The present invention has the problem that it is not necessarily suitable for use in a mass production line, etc., but an object of the present invention is to provide a novel plasma processing apparatus that can achieve both uniformity of film thickness and quality and mass productivity. There is a particular thing.

One of the features of the present invention is that the sea urchin 7% holder is configured in a cylindrical shape. A plasma reaction generating mechanism is arranged inside such a cylindrical holder. By arranging a large number of wafers to be processed in a cylindrical manner along the inner wall surface of the holder, it becomes possible to process a large number of wafers without impairing the uniformity of film thickness and film quality.

The invention will now be described in detail with reference to embodiments illustrated in the accompanying drawings.

FIG. 1 shows a plasma CVD process according to a first embodiment of the present invention.
10 indicates a gas introduction pipe having a gas blow-off hole tOa and through which N gas flows in the direction of the arrow; 1;
Reference numeral 2 denotes a cylindrical high-frequency shield tube having a gas flow hole 12a, and 14 a cylindrical wafer holder.The gas introduction tube 1o, the shield tube 12, and the holder 14 are arranged coaxially. A large number of wafers (
For example, a silicon wafer) is placed, '/-/l/
)-5iT between the cylinder 12 and the holder inner wall surface from below.
(4 gases are supplied. The boulder 14 is designed to rotate and hang in the direction shown by the intermittent mark R of the CVD process, which will be described later, with the wafer 16 mounted inside. Coils 18 and 22 are wound around each of the wafer boulders 16, and a high frequency source 20.24 is connected to each coil 18.22, respectively.

Now, due to the high frequency output from the power supply 20, the gas introduction pipe 10
When N2 gas is turned into plasma within the wafer 12, excited nitrogen atoms and molecules reach the surface of the wafer 12 through the holes 10a and 12a, where they react with 5iH4, and silicon nitride < s i3N4 is formed on the wafer 12. ) can be obtained. Before or after these five deposition processes, plasma etching is performed by converting Freon gas into plasma inside the holder 14 using the high frequency output of the @ source 24.

In the apparatus shown in FIG. 1, the wafer is arranged along the inner wall surface of the cylindrical holder 14, thereby making it possible to clean the inside.

The number of wafers charged can be greatly increased compared to conventional devices, and the uniformity of film thickness and film quality is good both within a wafer and between multiple wafers.

Such uniformity in film thickness and film quality is achieved by Ueno Holder 14.
In conjunction with the rotation of the holes 10a.

Further improvement is achieved by distributing 12a.

Further, since the wafer 12 is not directly exposed to plasma, it is hardly damaged by the impact of electrons in the plasma. Furthermore, since the N gas and the SiH4 gas are introduced separately, N and SiH are not turned into plasma at the same time, and therefore unnecessary induced products (for example, Sis) (s * Si @N5
(This is often caused by simultaneous plasma transformation)
It is possible to obtain a high quality silicon nitride film without deteriorating the film quality due to contamination.

FIG. 2 shows another embodiment in which the present invention is applied to a capacitor type CVD apparatus. In the same figure, a high frequency power source 4 is connected between the inner and outer electricity pipes 30 and 32, which also serve as gas introduction pipes.
0 is connected, and the gas blowing hole 30a of the inner electrode 30
N was blown out.

It is designed to turn gas into plasma. Outer electrode 3
SiH flows radially from the gas blow-off holes 32a of No.2.

Gas is blown out, and a cylindrical wafer holder 34 rotatable in the direction of arrow R is provided outside the pole 32 so as to surround it. Holder 3
A large number of wafers 36 to be processed are placed on the inner wall surface of the t-pole 30 and 32.Nitrogen atoms or molecules excited by the plasma generated between the t-poles 30 and 32 move to the t-pole as shown by the arrow EA. It reaches the wafer 12 side through a large number of through holes 32A provided in 32, and reacts with SiH there to cause silicon nitride deposition.

The apparatus shown in Fig. 2 also has a cylindrical wafer holder 34, so that a large number of wafers can be coated at once without impairing the uniformity of film thickness and film quality. Although the present invention has been described above with reference to several embodiments, the present invention is not limited to the above-mentioned embodiments and can be implemented in various modified forms. . For example, although the apparatus was generally vertical in the above embodiments, it could also be horizontal, thereby making the wafer holder longer in the lateral direction (and thus increasing the number of wafers charged). good

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a main part of a plasma CVD apparatus according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of a main part of a plasma CVD apparatus according to another embodiment of the present invention. Explanation of symbols in the figure 10...Gas introduction tube, 12...High frequency shield tube. 14...Wafer holder, 16...Wafer, 18.2
2...Coil, 30.32...Gas introduction pipe and 'RL
Pole, 34...Wafer holder, 36...+7.1/S
Figure 1 A/, 7 143- Figure 2

Claims (1)

[Claims] 1. ial With the object to be treated approximately toward the center,
A nearly cylindrical holder fbl held along the wall surface
A plasma generating section provided inside the holder. The plasma processing apparatus is characterized in that the object holding area of the holder and the plasma generation area are spaced apart from each other.