JPS6337615A - Plasma electrode - Google Patents

Abstract

PURPOSE:To reduce the generation of an impurity and dust, to prevent an adverse effect on a device and the deterioration of yield and to use the device for a prolonged term by constituting an electrode of a conductive member coated with a coating layer consisting of quartz or titanium nitride. CONSTITUTION:Lead electrodes 1a and 1b and electrodes 3 are organized of conductive members 3d, the surfaces of which are coated with coating layers 3c composed of quartz or titanium nitride TiN in thickness of 3-10mum and which are made up of carbon, a conductive metal or the like. Semiconductor wafers are inserted from upper sections along the electrode plates 3, the semiconductor wafers 4 are placed on quartz jigs 3b, and the electrode plates 3 are arranged onto a wafer boat 5 consisting of quartz, etc. Accordingly, the lead electrodes 1a and 1b and the electrode plates 3 are not sputtered by plasma and do not generate impurities and dust, thus preventing an adverse effect on a device and the deterioration of yield.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a plasma electrode used in semiconductor manufacturing equipment such as a plasma CVD equipment.

(Prior Art) Plasma electrodes generally used in semiconductor manufacturing equipment such as plasma CVD equipment include many disc-shaped electrode plates made of stainless steel, graphite, graphite coated with 5AC (silicon carbide) on the surface, etc. The electrode plates are supported by two rod-shaped lead electrodes arranged in parallel and parallel to the rows of electrode plates.

These electrode plates are fixed to one lead electrode on alternate sides by welding, and are configured to be locked to the other lead electrode via an insulator.

For example, in a plasma CVDVt system, a semiconductor wafer is placed between these electrode plates and inserted into a processing chamber.
Plasma is generated between the electrode plates by supplying high-frequency power from the lead electrode to the electrode plates in a predetermined reaction gas atmosphere, and C
Do a VD.

(Problems to be Solved by the Invention) However, in the conventional plasma electrode described above, for example, in a plasma electrode using an electrode plate made of stainless steel, there is a problem that impurity diffusion occurs and adversely affects the device. In a plasma electrode using an electrode plate made of the above, there is a problem in that the yield is deteriorated due to the generation of dust due to plasma sputtering. In addition, plasma electrodes using electrode plates made of graphite with S+C coating on the surface have the problem that the thermal expansion coefficients of graphite and S+C are similar, resulting in peeling of the SIC, which limits the period of use. .

The present invention has been made in response to such conventional circumstances, and
The present invention aims to provide a plasma electrode that generates less impurities and dust, does not adversely affect devices or deteriorate yield, and can be used for a long period of time.

[Structure of the Invention] (Means for Solving the Problems) That is, the present invention is a plasma electrode that is composed of a pair of electrodes arranged oppositely in a processing chamber, and in which high-frequency power is applied between the electrodes to generate plasma. , the electrode,
It is characterized by being composed of a conductive member whose surface is covered with a coating layer made of quartz or titanium nitride.

(Function) In the plasma electrode of the present invention, since the electrode is composed of a conductive member whose surface is coated with a coating layer made of quartz or titanium nitride, there is less generation of impurities and dust, and peeling of the coating does not occur. Never.

(Example) The details of the present invention will be described below with reference to the drawings.

Figures 1 and 2 show a plasma electrode according to an embodiment of the present invention. In the plasma electrode of this embodiment, two rod-shaped lead electrodes 1a and 1b each having a diameter of 7 mm and a length of 1 m and 80 cm are parallel to each other. These lead electrodes 1a and 1b are electrically connected to each other by being fixed by welding or the like to one of the lead electrodes 1a and 1b on different sides, and the other lead electrodes 1b and 1a are , these lead electrodes 1b.

A cylindrical insulator 2 made of quartz or the like is inserted into the cylindrical insulator 1a, and a hole or the like is formed on the periphery of the cylindrical insulator 2 in an arc shape or the like according to the outer diameter of the cylindrical insulator 2. A large number of disk-shaped electrode plates 3, each having a diameter of, for example, 175 mm and a thickness of, for example, about 3 mm, are arranged in parallel and held in place by a holder.

Note that the upper part of the periphery of the electrode plate 3 has, for example, a depth of 1 and a width of 30 mm.
A groove 3a for inserting tweezers with a diameter of about mm is formed in the lower part of the electrode plate 3, and a quartz groove for supporting semiconductor wafers is inserted from both sides of a small hole provided in the electrode plate 3 and is fitted and fixed. Two deodorants 3b are arranged at intervals along the peripheral edge of the semiconductor wafer 4, which is arranged concentrically on the surface of the electrode plate 3.

Moreover, these lead electrodes 1a, 1b and electrode 3 are
As shown in Fig. 2, it is composed of a conductive member 3d made of carbon or conductive metal whose surface is coated with a coating layer 3C of quartz or titanium nitride (T+N) with a thickness of 3 to 10 μm. .

Then, a semiconductor wafer 4 is inserted from above along the electrode plate 3, placed on a quartz jig 3b, and placed on a wafer boat 5 made of quartz or the like. At this time,
If necessary, 7-shaped grooves may be provided in the wafer boat 5 at every interval between the electrode plates 3.

The wafer boat 5 in such a state is exposed to, for example, plasma C.
The lead electrodes 1a, 1 are arranged in a processing chamber of a VD device, etc.
b are fixed and electrically connected to the terminals 6a and 6b of the door flange 6 of the plasma CVD apparatus. Then, a predetermined reactive gas such as SI H4 and N83 is passed through the processing chamber, and the terminals 6a, 6 are connected under this reactive gas atmosphere.
A high frequency power of, for example, 13.5 HH2 is applied between the opposing electrode plates 3 from b through leads m11a and 1b to generate plasma and perform processing such as the formation of CV D III.

In the plasma electrode of this embodiment with the above configuration, the lead electrodes 1a, 1b and the electrode plate 3 are made of conductive material such as carbon or conductive metal whose surface is covered with a coating layer 3C of quartz or titanium nitride with a thickness of 3 to 10 μm. It is composed of a sexual member 3d. Therefore, the lead electrodes 1a, 1b and the electrode plate 3 are not sputtered by the plasma and no impurities or dust are generated, which does not adversely affect the device or deteriorate the yield. In addition, unlike surface coatings, there is no possibility of peeling due to differences in thermal expansion coefficients, etc., and it can be used for a long period of time.

Although this embodiment describes a plasma electrode in which a large number of disc-shaped electrode plates are arranged in parallel and is used in a plasma CVD apparatus, the present invention is not limited to such an embodiment, and the electrode shape It goes without saying that it can be of any type, and can be used not only for plasma CVD equipment but also for any semiconductor device.

[Effects of the Invention] As described above, the plasma electrode of the present invention generates little impurity A5 dust, and can be used for a long period of time without adversely affecting the device or deteriorating the yield.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a plasma electrode according to an embodiment of the present invention, and FIG. 2 is a longitudinal cross-sectional view of the main part of FIG. 1a, 1b...Lead electrode, 3...Electrode plate, 4...Semiconductor wafer.

Claims (1)

[Claims] (1) In a plasma electrode consisting of a pair of electrodes arranged opposite to each other in a processing chamber, in which high-frequency power is applied between the electrodes to generate plasma, the electrode is covered with a coating layer made of quartz or titanium nitride on the surface. A plasma electrode comprising a coated conductive member.