JPS6357938B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a semiconductor thin film forming method for forming a semiconductor thin film on the surface of a substrate by sputtering, and an object of the present invention is to make it possible to form a semiconductor thin film at high speed by arc sputtering, and to facilitate the production of a power source. With the goal.

Generally, when forming a semiconductor thin film, the semiconductor thin film is formed using, for example, a flat plate magnetron sputtering apparatus as shown in FIG. In the figure, 1 is a cylindrical bell gear into which low-pressure oxygen gas and impurity gas are injected, and 2 is provided at the upper end of the bell gear 1 and is connected to the negative output end of a DC power source 3, which is cooled by cooling water. The target 4 is a cylindrical magnet placed on the target 2 and has an N pole and an S pole at the center and the periphery, respectively. Capturing electrons reduces the energy of the electrons and promotes ionization of the gas within the bell gear 1. Reference numeral 5 denotes a substrate supported by a substrate holder 6 and disposed at the lower end of the bell gear 1. The substrate 5 is connected to the positive output terminal of the power source 3, and is connected to the target 2 where oxygen ions collide with the target 2 and are ejected. Fine particles and molecules or atoms of the impurity gas fly to the substrate 5 and adhere to the substrate 5 to form a semiconductor thin film.

However, in this case, for example, when silicon is used as target 2 and semiconductor thin film is formed under conditions of 250W sputtering power, the film formation speed is
3 μm/hour, which has the disadvantage that semiconductor thin films cannot be formed at high speed.

This invention has been made with the above-mentioned points in mind, and includes installing a crucible containing an evaporated material in a vacuum chamber, disposing an anode ring above the crucible in the vacuum chamber, and disposing the anode ring in the vacuum chamber. A substrate is arranged above the anode ring in a room, the positive and negative output ends of a DC power source are connected to the anode ring and the crucible, respectively, and the anode ring and the crucible are energized by the power source while cooling the crucible. , generating an arc between the surface of the evaporated material and the anode ring to evaporate the evaporated material, and supplying a predetermined amount of impurity gas near the surface of the evaporated material to reduce fine particles of the evaporated material by evaporation. and the impurity gas are scattered onto the substrate to form a semiconductor thin film on the surface of the substrate.

Therefore, according to the method for forming a semiconductor thin film of the present invention, an arc is generated between the surface of the evaporated material and the anode ring, and the evaporated material is evaporated by the arc to form fine particles of the evaporated material and molecules or atoms of impurity gas. By scattering and arc spatter,
Semiconductor thin films can be formed at high speed, and the output voltage of the power supply can be lowered to facilitate production of the power supply.

Next, this invention will be explained in detail with reference to FIG. 2 showing one embodiment thereof.

In the figure, 7 is a cylindrical metal crucible installed in a vacuum chamber, 8 is a cooling water flow path formed by integrally providing a partition wall 8' inside the crucible 7;
9 is a storage section formed inside the partition wall 8'; 10
A cooling water outlet 11 formed at the upper end of the side surface of the crucible 7 and communicating the flow path 8 with the outside is the crucible 7
A cooling water outlet 12 is formed at the lower end of the side surface and communicates the flow path 8 with the outside, and a cooling water outlet 12 is formed at the upper end of the partition wall 8' and connects the storage section 9 with the outside. 13 is a solid evaporated material made of aluminum, silicon, etc. stored in the storage part 9; 14 is an anode ring disposed above the crucible 7 in the vacuum chamber; 15 is connected to the anode ring 14 at one end; The switch 16 has one end connected to one end of the switch 15, and the arc start contact body is attached to the other end of the spring 17 and is movable up and down. The positive and negative output ends are respectively connected to the other end of the switch 15. and a DC power supply connected to the crucible 7, 19 is a temperature-adjustable substrate holder 20
21 is a shutter movably provided between the substrate 19 and the anode ring 14, and the shutter 21 is movably provided between the surface of the evaporated material 13 and the anode ring 14. After the arc generated during is stabilized,
The shutter 21 is moved and removed from between the substrate 19 and the anode ring 14.

Next, the operation of the embodiment will be explained.

First, the shutter 21 is disposed between the substrate 19 and the anode ring 14, and the contact body 1
The lower end of the crucible 7 is brought into contact with the evaporated material 13, impurity gas is supplied from the supply port 12 to the storage section 9 of the crucible 7, and cooling water is distributed from the inlet port 10 to the flow path 8. Switch 1 while cooling
5 is turned on, the anode ring 14 and the contact body 16
Then, energization to the crucible 7 is started, and the evaporated material 13
The portion of the surface that is in contact with the contact body 16 is heated. When the heated portion of the surface of the evaporated material 13 becomes hot and red hot, the contact body 16 is moved upward as shown by the dashed line in FIG.
An arc is generated between the surface and the anode ring 14, the vaporized material 13 is rapidly evaporated by the arc, and fine particles of the vaporized material 13 begin to scatter together with molecules or atoms of the impurity gas.

Next, when the arc becomes stable and particles and impurity gas molecules and atoms are actively scattered, the shutter 21 is moved in the direction of the solid line arrow in FIG. Evaporated matter 1 removed and scattered from between 14 and 14
The particles of No. 3 and the molecules and atoms of the impurity gas collide and adhere to the substrate 19, forming a semiconductor thin film on the surface of the substrate 19.

At this time, for example, when silicon is used as the evaporator 13 and sputtering is performed under conditions of a sputtering power of 200 W, the film formation rate is 2.5 μm/min, and a semiconductor thin film is formed at a very high speed.

Therefore, according to the embodiment, the evaporated material 13
An arc is generated between the surface and the anode ring 14, and the arc evaporates the evaporated material 13 to scatter fine particles of the evaporated material 13 and impurity gas molecules or atoms, and the surface of the substrate 19 is Semiconductor thin films can be formed at high speed.

Furthermore, since the semiconductor thin film is formed by arc sputtering, the output voltage of the power source 18 can be lowered to about 200 V, and the power source 18 can be manufactured easily.

Further, since a semiconductor thin film with a rough surface structure can be formed on the surface of the substrate 19 by arc sputtering, a semiconductor thin film with a large surface area can be provided, and by forming a semiconductor thin film as a photovoltaic element, Highly efficient solar cells can be easily obtained.

Furthermore, since the sputter voltage is about 200V,
Damage to the substrate 19 is reduced when particles of the evaporated material 13 are attached to the substrate 19 due to collision.

In addition, by controlling the temperature of the substrate holder 20 to raise or lower the temperature of the substrate 19, or by lowering the sputtering voltage from the power source 18, the temperature of the substrate 19 can be increased or decreased.
The surface structure of the semiconductor thin film on the surface can be made smooth or rough, and a semiconductor thin film with a desired surface structure can be obtained.

If the evaporated material 13 is a powder, instead of contacting the contact body 16 when starting the arc, an electron beam is applied to the upper surface of the powdered evaporated material 13, as shown by the broken line arrow in FIG. Irradiate and anode ring 14
An arc may be generated between the evaporated material 13 and the evaporated material 13.

[Brief explanation of drawings]

FIG. 1 is a cutaway front view of a conventional method for forming a semiconductor thin film, and FIG. 2 is a front view of a conventional method for forming a semiconductor thin film.
FIG. 3 is a cutaway front view of the embodiment. 7... Crucible, 13... Evaporated material, 14... Anode ring, 18... DC power supply, 19... Substrate.

Claims (1)

[Claims] 1. A crucible containing evaporated material is installed in a vacuum chamber, an anode ring is placed above the crucible in the vacuum chamber, a substrate is placed above the anode ring in the vacuum chamber, and a DC power supply is provided. The positive and negative output ends of are connected to the anode ring and the crucible, respectively, and the anode ring and the crucible are energized by the power source while cooling the crucible, and an arc is generated between the surface of the evaporated material and the anode ring. At the same time, a predetermined amount of impurity gas is delivered near the surface of the evaporated material, and fine particles of the evaporated material and the impurity gas due to evaporation are scattered onto the substrate, and the impurity gas is scattered onto the substrate surface. A method for forming a semiconductor thin film, the method comprising forming a semiconductor thin film.