JPS5896727A - Manufacture of amorphous silicon semiconductor device - Google Patents

Abstract

PURPOSE:To sufficiently perform purity for the surface of a substrate by a method wherein an inert gas ion obtained in a gas discharge tube is irradiated at the substrate as a process before forming an amorphous Si layer. CONSTITUTION:A substrate 14 is positioned in a bell jar 11 to make the inside of the bell jar in a high vacuum state. Next, while applying a DC negative voltage or an AC voltage to the substrate 14 by a power source 16, an inert gas ion obtained in a gas discharge tube 17 is aimed at the substrate 14. Then, Si from an Si evaporation source 18 is evaporated and deposited on the substrate 14. In this way, purification for the surface of the substrate 14 is performed by irradiating the inert gas ion generated in the discharge tube 17 at the substrate 14 to sufficiently perform the purification of the substrate 14.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing an amorphous silicon semiconductor device.

In the near future, amorphous silicon (hereinafter referred to as "a-silicon J") Vi can be produced extremely advantageously compared to crystalline silicon, and it may have good properties. (2) MC5 materials are attracting attention for semiconductor devices such as solar cells, electric field difference transistors, and photoconductors.

Therefore, in a-silicon, its amorphous structure has an irregular atomic arrangement, so to speak.
Because there are many dangling bonds in the barking state,
Since one cap state car is required for one cap state, it is not possible to obtain the remarkable Doching effect, and therefore the characteristics of the semiconductor device are inferior. It is necessary that the ring bond be made of a button seal or a-silicon. Conventionally, there are various methods to obtain practical a-silicon by sealing the dangling bonds, such as glow emission, evaporation, and sputtering. The major advantage is that the stress can be easily applied during insertion, which is a boon for industrial-scale manufacturing.

In the above method, it is necessary to clean the surface of the substrate by removing impurities. For example, a high voltage is applied to the board M' and air is discharged in the vacuum chamber (3), causing the ions generated thereby to collide with the surface of the blue board C, thereby cleaning the surface of the board. or this method (in C, the partial pressure of C in the C is required to be 10-' to 10-!Torr in order to discharge the C, so the substrate of the 10th ion is Due to the limitations on the impact energy for
Especially when using a metal N frame as a substrate,
This results in gold pA residue remaining on the substrate surface.
・Ra, a-silicon layer and electricity t! 9] Interface bracket @ is bad<
7. Internal resistance is a powerful force, and this result example has a large
s 'FJf N! If it is a W7 analog element or a field effect transistor, its function and characteristics will be greatly impaired.

1, the board is gold μ, N Germany! Even in other cases, the a-silicon layer is likely to peel off from the substrate and sufficient durability cannot be obtained.

The present invention has been made based on the above circumstances, and it is necessary to thoroughly clean the substrate in Table 1r4, and to manufacture a silicon semiconductor device having good characteristics.
The purpose is to provide the force U'.

A feature of the present invention is that a substrate placed in a vacuum atmosphere is irradiated with inert gas ions obtained in a gas discharge tube, and then LL gauze is applied to a substrate placed in a vacuum atmosphere in a gas discharge tube. While introducing active hydrogen and hydrogen ions, silicon is evaporated from a silicon evaporation source provided in the open air atmosphere, thereby forming a Ka-silicon layer on the substrate.

The present invention will be explained below with reference to the drawings.

In the present invention, as shown in FIG. 1, a vacuum pump (not shown) is attached to a Pel jar 11 forming a vacuum chamber through an exhaust passage 13 that connects a butterfly valve 12, and the Pel jar 11 is kneaded. For example, 10"-"
10-' The TorrO high vacuum state is established, the substrate 14 is placed inside the Pelger 11, and the substrate 1 is powered by the power source 16.
4, apply a full negative current voltage or AC voltage of 10 kV or less, preferably IL < H (5) 500 to 6000 V, and connect the outlet to the Pelger so that it faces the substrate 14. The first gas introduction pipe 171 and the valve 17 of the gas discharge tube 17 are connected to the gas discharge tube 17 connected to the gas discharge tube 11.
2, an inert gas such as argon gas is introduced through the substrate 1, and ions of the inert gas generated by the discharge are transferred to the substrate 1.
Irradiate to 4. Without breaking the vacuum, meeting 11 fi
The second gas introduction tube 173 and the second
Hydrogen gas is introduced through the first valve 174 (at this time, the first valve 172 is not closed), and active hydrogen and hydrogen ions generated by the discharge are introduced into the Pel jar 11 while the heater 5 On the substrate heated to a flow rate of 150 to 500°C, preferably 250 to 450°C, silicon is deposited by evaporation from a silicon evaporation source 18 provided opposite to the base f214, thereby forming a dangling bond. An a-silicon ri4 blocked by hydrogen atoms is formed on the base 17k114, and a semiconductor element is formed in this a-silicon layer to produce a semiconductor device.

(6) In the above, any heating means such as resistance heating, electron gun heating, induction heating, etc. can be used to heat the silicon evaporation 918.

Further, in the example i' of the hand poison gas discharge tube 17, as shown in Figure 2, one i' of the cylindrical 1 having the gas population 21
A discharge space member 24 made of, for example, cylindrical glass and surrounding a discharge space 23 with one N-pole member 22 at one end, and an outlet provided at the other end of this discharge space member 24. The other ring-shaped electric 81 that covers 25! Part 2
6. Due to the constitutive force, when a meandering or alternating current voltage is applied between the one electrode member 22 and the other electrode member 26, hydrogen atoms or molecules are activated energetically! Active hydrogen and ionized frozen ions are discharged through outlet 25. In this illustrated example, Hoshanku 1
1ij It has a double pipe structure with 24 members and is configured to allow cooling water to flow through it, and 27 and 28 indicate the cooling water inlet and outlet. Reference numeral 29 designates a cooling (7) moving fin of one of the tm section members 22.

1. When C gas DN%=17, the supply amount of argon gas and the supply amount of hydrogen gas are both about 50 cc/min, and the yI pressure port is 50 (,1 to 600 cc/min).
7 The discharge 11 flow tl is also assumed to be 0.6A culm.

On the other hand, in the present invention, as a step before forming on the a-silicon tt tl-substrate 14, the substrate 14 is irradiated with inert gas C ions generated in the gas discharge tube 17, thereby forming the substrate 14c. ) Since the surface is to be cleaned, the collision speed of ions that collide with the surface of the substrate 14 may be limited, as in the case where the surface is cleaned by blasting air in a vacuum chamber. No, top F
The collision speed of the ions on the substrate 14 and the irradiation 1 can be controlled.Moreover, the irradiated ions are inert gas ions and are unlikely to react with the material of the substrate 14. Can be thoroughly cleaned.

Therefore, when the substrate 14 becomes a gold NN electrode, the metal oxide on the substrate 14 can be reliably removed, and as a result,
Subsequently, by forming an a-silicon layer on the substrate 14 without breaking the fresh air, the interface bond between the a-silicon layer and the N pole becomes good, and in the case of a thick battery, the conversion efficiency is improved. In the case of an analog element or a field effect type transistor, its function and characteristics are not impaired.

Even if the substrate 14 is not a metal tube or a pole, impurities on the substrate 14 are reliably removed.
Since the adhesion of the a-silicon layer to No. 4 is good, high durability can be obtained. If an inert gas with a large amount of atomic oil, such as argon gas, is used, the sputtering effect will be large.
The substrate 14 can be cleaned more reliably.

Furthermore, in the present invention, since the formation of the a-silicon layer is carried out by vapor deposition of silicon in the presence of active hydrogen and hydrogen ions obtained by exposing the water-accumulated gas to metal, the tangling of the a-silicon layer is ensured. Bonds are sealed by hydrogen atoms (9) Chained a-silicon is obtained o Moreover, the heating temperature and applied voltage of the substrate 14 are controlled, the evaporation rate of silicon is controlled, and the hydrogen gas supplied to the IT gas discharge tube 17 is controlled. Furnace 1
By controlling the discharge voltage, it is possible to independently control the active culm of the active hydrogen introduced into the bellgear 11 and the contamination of hydrogen ions, so that a-silicon with the desired good force characteristics can be controlled. You get layers.

In addition to the above, in the present invention, it is easy to increase the film forming speed, and it is possible to form a thick a-silicon layer in a short time. Since it is possible to obtain an a-silicon layer having a uniform composition and a uniform thickness in the plane direction even in the case of a semiconductor device, it is possible to advantageously manufacture a semiconductor device.

In the present invention, the hydrogen gas discharge tube and the inert gas discharge tube may be separate, but if the electrification conditions such as the 1j9:¥H pressure for these gases are aligned as described above. If the discharge tubes are common, as in the embodiment shown in Figure 1, it is sufficient to use a common discharge tube. Here, the time required to heat the substrate 14 is about 1 to 20 minutes, and during this time, the oxygen deposited on the inner wall of the Pelger 11 causes oxides to form on the surface of the substrate 140. However, if the substrate 14 is heated while being irradiated with inert gas ions, it is quite likely that oxides will be formed on the substrate 14J, so the cleaning process described above is not necessary. By performing the vapor deposition process immediately after the step, it is possible to reliably prevent the formation of an a-silicon layer with oxide remaining on the substrate 14, and it is also possible to increase the work efficiency.

Actually, using the apparatus shown in Figure 1, the surface of a substrate made of stainless steel was completely irradiated with argon gas ions.
1-n type a- transparent tube f made of silicon layer and ITO
! A solar cell was constructed by forming lil in this order, and this solar cell had good characteristics with a conversion efficiency of 55%.
The surface of the substrate on which the a-silicon (11) layer was not formed had a clean mirror surface.

On the other hand, when the solar cell was exposed to the same conditions except that no ion irradiation with argon gas was performed, the conversion efficiency of this solar cell was 0.5% and it could not be put to practical use. The surface of the substrate on which the silicon layer was not formed had changed to a brown color.

As described above, according to the present invention, it is possible to provide a method for manufacturing an a-silicon semiconductor device that can sufficiently clean the surface of a substrate and has good characteristics.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of a manufacturing apparatus used in method v2 of the present invention, and FIG. 2 is an explanatory diagram showing an example of a waste discharge tube C) used in the method of the present invention. 14... Board 15... Heater 17
...Gas discharge tube 18...Silicon evaporation r! 21...Gas inlet 2
2.26... Den! # Member 23...Discharge space 25
...roll 121

Claims (1)

[Claims] 1) After irradiating the blade placed in a vacuum atmosphere with ions of the inert gas obtained in the N tube in the gas atmosphere, it was gauged and exposed in the gas T II flying tube during the vacuum atmosphere. t1
While introducing active hydrogen ions into the active hydrogen, evaporate silicon from a silicon evaporation source provided in an air atmosphere to form an amorphous silicon layer on the same plate. Manufacturing method of amorphous silicon semi-container cup characterized by