JPS6153428B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrode holding device used in an externally heated plasma chemical vapor phase generation device.

Conventionally, when producing amorphous silicon films for solar cells, external thermal plasma chemical vapor phase production equipment has been used because of its high production efficiency. However, in this device, the reaction tube and its contents are kept at the optimal temperature for chemical vapor phase generation, so vapor phase growth films are likely to be generated even around the plasma generation area, and this results in Abnormal discharge may occur between the two parts, and a phenomenon may occur in which a vapor-phase growth film is only partially formed.

Generally, amorphous silicon films for solar cells require three types of films: P layer, I layer, and N layer.
If such partial growth occurs as described above, a problem arises in that a film with a complete three-layer structure cannot be formed.

For this reason, as one of the measures taken to solve the above problem, the electrode holding device as shown in Figs. 1 and 2 (this is a sectional view taken along line A-A' in Fig. 1)
Alternatively, there are the ones shown in FIGS. 3 and 4 A and B (these are cross-sectional views taken along lines B-B' and C-C' in FIG. 3).

The one shown in Figs. 1 and 2 has a connecting plate 1 made of a heat-resistant insulator such as quartz at both ends, and two connecting rods 2 made of quartz or the like fixed to the connecting plate 1 are provided between them. Insert and hold the electrodes 3 into grooves cut at regular intervals on the rod 2 (as shown in Figure 2), and connect every other electrode 3 with a lead wire (not shown).
This constitutes a pair of electrode groups. In this case, the connecting rod 2 is provided with a short-circuit prevention tube 4 made of quartz or the like that covers the outer periphery of the connecting rod 2 at intervals between each electrode. However, although this short-circuit prevention tube 4 does not form a film on the surface of the connecting rod 2 and prevents short circuits, discharge occurs even through the film formed on the outer periphery of the short-circuit prevention tube 4, so that there is no uniformity between the opposing electrodes. A problem arose in that a similar plasma was not generated.

Figures 3 and 4 show other conventional devices;
As in the case shown in the figure, connecting plates 1 made of heat-resistant insulators such as quartz are placed at both ends, and three conductor rods 5 and 6 are attached to the connecting plates 1 at both ends at positions roughly divided into thirds near the outer periphery of the connecting plate 1. Provided between. The conductor rods 5 and 6 are provided one on the upper side and two on the lower side, and the two on the lower side are connected with lead wires to have the same potential. Among these conductor rods, the lower two conductor rods 5 are connected to the first conductor rods 5.
As shown in Fig. 2, grooves into which the electrodes 8 are inserted are cut at regular intervals, and the upper conductor rod 6
An electrode 8 having a notch that does not come into contact with the electrode 8 is inserted and held. One conductor bar 6 on the upper side has two conductor rods on the lower side.
An electrode 7 is provided with a notch that does not touch the conductor rod 5 and a hole passing through the conductor rod 6 on the upper side, and is suspended between the electrodes 8 at regular intervals. With such an electrode structure, short circuits as described above are unlikely to occur, but short circuits may occur due to discharge between one electrode group and the conductor rods of the other electrode group, that is, between 7 and 5 and 8 and 6. It is difficult to generate such plasma, and the electrode 7 suspended from the top
There is a problem in that it is difficult to attach and detach the board to the device.

The present invention has been made to solve these problems, and it is easy to attach and detach the substrate to each electrode, prevents discharge from occurring on surfaces other than the opposing surfaces of the electrodes, and prevents short circuits at the electrode holding part. This provides an electrode holding device that is unlikely to cause this. This will be explained in detail below with reference to the drawings.

FIG. 5 is a top view of a state in which an electrode is inserted into the electrode holding device of the present invention. FIG. 6 is a side view seen from a direction perpendicular to the electrode surface. In the figure, reference numeral 9 denotes a connecting plate, which is a semicircular plate in this embodiment, but may also be a semicircular plate. 10 and 11 are connecting rods, 12 and 13 are electrode holding rods, and 14 is a short circuit prevention tube. 15 is a conductor rod, 16 is a connecting rod, 17 is a flake prevention tube, and 18 is an electrode.

In the present embodiment, four wires are arranged in parallel from substantially equally spaced positions on connecting plates 9 made of arc-shaped heat-resistant insulators on parallel planes, and each of which has both ends fixed to each connecting plate 9. It consists of connecting rods 10 and 11 made of heat-resistant insulators, and two conductor rods 15 held at both ends of the arc of an arc-shaped connecting plate 9 and provided parallel to the connecting rod 10. The four connecting rods 10 and 1
1 consists of two sets of connecting rods arranged every other pair as a group, and connecting rods 10 or 11 of each group.
Electrode holding rods 12 or 13 made of heat-resistant insulators are fixed on surfaces parallel to the connecting plates 9 at both ends in a direction toward the center of the arc. This electrode holding rod 12 or 1
3 has a notch for inserting an electrode 18 at the end opposite to the connecting rod 10 or 11. Further, surfaces including a pair of electrode holding rods 12 or 13, that is, held electrodes 18, are alternately fixed to connecting rods 10 or 11 at equally spaced positions. The length of this electrode holding rod 12 or 13 needs to be longer than the distance between the electrodes 18 held and adjacent electrodes. Furthermore, short-circuit prevention tubes 14 made of heat-resistant insulators are provided at both ends of the connecting rod 10 or 11 in the vicinity of where they are fixed to the connecting plate 9, and which cover the outer periphery of the connecting rod 10 or 11 at intervals. A plurality of protrusions are provided on the inner surface of the short-circuit prevention tube 14 to maintain a distance from the outer periphery of the connecting rod 10 or 11. The two conductor rods 15 have connection rods 16 alternately arranged on the surface including the electrode holding rods 12 or 13 in a direction toward the center of the arc.
And it is arranged so that it may contact the inserted electrode 18.

As another embodiment, in addition to the above embodiment, a flake prevention tube 17 made of a heat-resistant insulator is attached to the intermediate portion of the conductor rod 15 where the connecting rod 16 is disposed.

Next, the operation of the electrode holding device of the present invention will be explained. A substrate to be processed is mounted on the opposing surface of each electrode 18 by a method not shown, and this electrode 1
8 is inserted into the notch at the tip of a pair of electrode holding rods 12 or 13, and connected to the conductor rod 15 with a connecting rod 16. The electrode holding device with each electrode 18 mounted thereon in this manner is inserted into a reactor of an externally heated plasma chemical vapor generation apparatus which is already maintained at a predetermined temperature.
A reaction gas is introduced into the reactor while the entire electrode holding device is maintained at a predetermined temperature, and high frequency power is applied to the conductor rod 15 and the connecting rod 16 under a reduced pressure state of a constant pressure.
The voltage is applied to each group of electrodes 18 through.

In this way, plasma is generated between each electrode 18, and chemical vapor phase generation is performed. In the case of this embodiment, each electrode 18 is held by an electrode holding rod 12 or 13 that is longer than the interval between the electrodes, so even if the electrode holding rod 12 or 13 or the connecting rod 1
Even if a vapor-phase-generated film is grown on the electrodes 0 or 11, the distance between the electrodes is the shortest, so abnormal discharge as described above between the electrodes and a portion other than the electrodes is unlikely to occur.

In this embodiment, the distance between the electrodes 18 at both ends of the electrode group and the connecting plate 9 is set to be sufficiently long compared to the electrode spacing, and the short-circuit prevention tubes 14 provided on each connecting rod 10 and 11 prevent Even if a vapor-grown film is formed on the connecting plate 9, the connecting rods 10 and 11, and the short-circuit prevention tube 14, no vapor-grown film will be formed between the short-circuit prevention tube 14 and the connecting rods 10 and 11. There is no short circuit between the opposing electrodes 18.

In another embodiment, the flake prevention tube 17 placed over the conductor rods 15 between the connecting rods 16 prevents flakes from forming, and the generated flakes can be easily removed by replacing the flake prevention tube 17.

As described above, the electrode holding device of the present invention generates stable plasma to ensure the quality of the vapor-phase-generated film, and has a structure that allows extremely easy attachment and detachment of the electrode. Furthermore, the short circuit prevention pipe 14 and the flake prevention pipe 17
The practical effects are extremely large, such as being able to reduce the number of times the entire electrode holding device is cleaned.

[Brief explanation of the drawing]

Fig. 1 is a plan view of a conventional electrode holding device, Fig. 2 is a sectional view taken along line A-A' in Fig. 1, Fig. 3 is a plan view of another conventional electrode holding device, and Fig. 4 is a A sectional view taken along line B-B' in Figure 3, and Figure 4B is a cross-sectional view taken along line C-B' in Figure 3.
5 is a plan view of the electrode holding device of the present invention, and FIG. 6 is a side view of the electrode holding device of the present invention viewed from a direction perpendicular to the electrode surface. In the figure, 9 is a connecting plate, 10 and 11 are connecting rods, 12 and 13 are electrode holding rods, 14 is a short-circuit prevention tube, 15 is a conductor rod, 16 is a connecting rod, and 17 is a flake prevention tube.

Claims (1)

[Scope of Claims] 1. An electrode holding device for an externally heated plasma chemical vapor phase generation device, comprising: two connecting plates, two sets of connecting rods having both ends fixed to the respective connecting plates between the connecting plates; It consists of two conductor rods held at both ends by respective connecting plates between connecting plates, and each pair of connecting rods holds electrodes at a certain interval, and has electrode holding rods longer than the electrode spacing, and an electrode holding rod at both ends. A short-circuit prevention tube is provided between the connecting plate and the electrode holding rod, and covers the outer periphery of the connecting rod at a distance, and the conductor rod is provided with a connecting rod that connects to every other electrode. Electrode holding device for external thermal plasma chemical vapor generation equipment. 2. In an electrode holding device for an externally heated plasma chemical vapor generation device, there are two connecting plates, two sets of connecting rods with both ends fixed to the respective connecting plates between the connecting plates, and two sets of connecting rods with both ends fixed between the connecting plates. It consists of two conductor rods held by a connecting plate, and the connecting rod has an electrode holding rod that holds electrodes at a certain interval for each set and is longer than the electrode spacing, a connecting plate at both ends, and an electrode holding rod. A short-circuit prevention tube is provided between the connecting rods at intervals and covers the outer periphery of the connecting rod, and the conductor rod is provided with a connecting rod connected to every other electrode and a short-circuit prevention tube covering the outer periphery of the conductor rod between these connecting rods. An electrode holding device for an externally heated plasma chemical vapor phase generation device, characterized in that it is provided with a flake prevention tube.