TW591130B - Method and apparatus for directly forming polycrystal silicon film - Google Patents

Abstract

A method and an apparatus for directly forming polycrystal silicon film are provided. In low pressure a silicon powder is injected to become atomized silicon liquid by a plasma spraying torch in order to directly become a polycrystal silicon film on a substrate. The method mainly comprises the steps of: placing a substrate on a pedestal in an airtight chamber, wherein the temperature of the substrate is controlled by the pedestal; controlling the pressure of the airtight chamber under 100 Torr; and plasma spraying silicon powder with high temperature plasma-forming gas onto the substrate for directly forming polycrystal silicon. Thus, that is a vacuum plasma spray (VPS) method to form a polycrystal silicon film.

Description

591130-^^ 89121049_Year Month Day Amendment __ V. Description of the Invention (1)-[Field of the Invention] The present invention relates to a method for directly forming polycrystalline silicon, especially a method capable of forming directly without annealing (anneal ing). Method for polycrystalline silicon 0 [Previous technology] In the manufacture of semiconductors, thin-film solar cells, and the optoelectronic industry such as TFT-LCD or TFT-0LED, a silicon film needs to be formed at low temperature, that is, PV, PECVD or CVD below 60 (TC) A method of vapor deposition of a silicon thin film 'but the Shi Xi thin film does not have enough energy to form polycrystalline silicon [Poly silicon]' during deposition and can only form amorphous Shi Xi [am〇rph〇us s 111 con], so in order to obtain The best polycrystalline silicon usually requires annealing (anneaHng) process on the amorphous silicon to obtain a polycrystalline silicon structure. The method of forming polycrystalline silicon by annealing is disclosed in the Republic of China Patent Gazette Publication Nos. 324833 and 357388, which are in Africa. The crystalline silicon film is irradiated with a laser beam to make it radiant. The disadvantage is that during this annealing process, extremely high laser equipment is required. The construction cost is too high and laser scanning is used. It is necessary to review the formation speed. Another method for forming silicon is, for example, Japanese Laid-Open Patent Publication No. 6-1 32220, which uses a "and" mixed vapor deposition stone in a CVD apparatus. In the film, a thin polycrystalline stone is first deposited at a slow flow rate as a seed layer for the subsequent amorphous silicon. [Seed u The slow flow rate of polycrystalline silicon is lower than normal% # & a μ / + ± J / There is a lot of accumulation, and then it is deposited-appropriate thickness = amorphous silicon with several times the velocity of the hand, and finally placed in an electric furnace

Page 5 591130 Amended case number 89112049 V. Description of the invention (2) Annealed at 600 ° C. Since it already has a seed crystal, it can be converted from amorphous silicon to polycrystalline silicon in a short time, but in general, in consideration The total formation time [from deposition to annealing] of polycrystalline silicon has not been saved, because it has taken too long to form a sublayer of polycrystalline silicon at a low speed. In U.S. Invention Patent No. 5, 773, 32 No. rpolysilicori grown by pulsed rapid thermal annealing ", it is disclosed that polycrystalline silicon is formed by a pulsed rapid thermal annealing (PRTA) method, but two dielectrics need to be formed first in the process. The electrical layer is sandwiched with [sandwi ch] amorphous silicon, and then partially etched to facilitate the formation of a metal seed layer such as Ni, Li, or "and other metal seed layers [㈣ 七 ^ seed layer] in contact with" when pulsed thermal annealing is applied [prta 〔Method can quickly form polycrystalline silicon, but obviously it has too many forming steps and has difficulties in mass production in related industries. [Objective and Summary of the Invention] The main purpose of the invention is to provide a direct formation method of polycrystalline silicon. Vacuum Plasma Spraying Method [Vacuum piasma sprays silicon powder on a substrate, enabling polycrystalline silicon to be formed directly without the need for annealing. = The second purpose of the invention is to provide a direct-forming assembly of polycrystalline silicon. Plasma spraying of silicon powder in a low-pressure air-tight chamber allows silicon to form polycrystalline silicon directly during deposition. ^ Ming Zhi's direct formation of polycrystalline silicon & In the state of spraying, the spraying method is to apply the imported stone powder to form an atomized stone liquid and apply directly to the polycrystalline silicon based on the color of the pet. The steps mainly include placing a substrate on a milk-tight inner stage, where This stage can control the temperature of the substrate; ΕΗPage 6 591130 __ Case No. 8912104Q_Year Month Day_Amendment _ V. Description of the invention (3) Control the pressure of the airtight chamber to less than 100 Torr; and plasma spraying will be plasma The formation of gas drives the silicon powder to be sprayed on the substrate at high temperature, and polycrystalline silicon is directly formed on the substrate. Therefore, it is a vacuum plasma spraying (VPS) method for forming polycrystalline stones. [Detailed description of the invention]

The method for directly forming polycrystalline silicon according to the present invention is to form the atomized silicon powder (Si 1 icon powder) into an atomized, silicon liquid and apply it to a substrate by a plasma spray coating in a low pressure state. And further directly form poly-silicon film, so it is a vacuum plasma spraying method [Vacuum Plasma Spray, VPS]. The VPS method of the present invention can directly and efficiently form polycrystalline silicon on a substrate. It does not need to be familiar with the process of forming amorphous silicon and then annealing (annealing) and then crystallizing it into polycrystalline silicon, so it effectively simplifies the forming process and forming time of polycrystalline silicon, so it can be used in semiconductors, optoelectronics and Mass production of polycrystalline silicon in the solar cell industry. As shown in FIG. 1, it is a device that can be used to implement the above-mentioned direct formation method of polycrystalline silicon. It mainly includes an airtight chamber 10, a carrier 20, an extraction device 30, and at least one plasma spraying. 4〇 〔piasma Spray gun〕 0

The airtight chamber 10 'forms a space that blocks external air to facilitate the control of the type of gas during processing. The stage 20 is provided inside the airtight chamber 10 to carry the substrate 60, and the stage 20 is provided with a temperature control device 21 (such as a heating coil and a cooling and radiating device). The temperature of the control substrate 60 is between 500 and 95. (rc, preferably

591130 --- Cliff number 89121 discussion _ year _I day Amendment 5. Description of the invention (4) 600 ~ 70 0 ° C [that is, the crystallization temperature of silicon]. The suction device 30 is used to control the pressure of the airtight chamber 10, and is generally controlled to a pressure close to a vacuum [00 〇 100 〇TOR].

Plasma spray gun 40 has a cathode 41, an anode 42, an air vessel introduction device 43, and a silicon powder introduction device 44 at a nozzle [nozzle]. The cathode 41 and the anode f 42 are connected with a DC power source or a high-frequency AC power source. The anode 41 is used to strike the% pole 42 to form an eiectric arc. Conventionally, the anode 42 is made of a crane and has a proper insulation treatment, and the electropolymerization gas introduced by the gas introduction device 43 is formed. [Piasma — f〇rming gy] 'Gases such as hydrogen [H2], helium [He], argon [Ar], or nitrogen [N2] should pass through the above arc formation site, so that the passing gas can obtain extremely high energy [up to Above 1000 degrees Celsius], and then a plasma is formed, and at the same time, the silicon powder introduced by the stone powder introduction device 44 [its particles are driven by the gas ejected from the gas introduction device 43 in the Bu 50 system, and the plasma is sprayed on The action of the gun 40 causes the silicon powder to be converted into atomized silicon liquid. In the present invention, the number and fixation of the plasma spray gun 40 are not limited. Preferably, the plasma spray gun 40 includes a moving device for The plasma spray is grabbed 40% into a reciprocating movement to spray On the silicon substrate 60, furthermore, on the detailed structure of the plasma discharge may refer to the United States made grab

Ming Patent Nos. 3, 145, 287 and 4,430, 546. When a substrate 60 is placed on the stage 20 for processing, at this time, the pressure of the airtight chamber 10 is close to a vacuum (less than 100 Torr), and a number of finely atomized silicon liquids 70 are sprayed by plasma spraying 40 [by introducing silicon Powder conversion], as shown in Figure 2a, the Shixi liquid 70 is dispersed and deposited on the substrate 60, and the temperature control device of the stage 20 can keep the temperature of the substrate 60 at the crystallization temperature of silicon [about 65 ° C], As in section 2b

591130 Room No. 89 丨 21049 V. Description of the Invention (5) As shown in the figure, 'the temperature control device 21 of the stage 20 makes the substrate 60 have a temperature variation that decreases gradually toward the stage 20, so it can be directly formed on the substrate 60. Polycrystalline silicon 71 with better directivity, wherein the polycrystalline silicon 71 can be of any desired thickness', which is about 0.1 ~ 50 / zm according to industrial requirements. Therefore, the method for directly forming the polycrystalline silicon according to the present invention can not only eliminate the annealing process, but also The method of forming a silicon film in the mist liquid phase of its VPS is much faster than the conventional method of forming a silicon film by vapor deposition such as PVD, PECVD, and CVD.

In order to make the silicon powder have better dispersion when the silicon liquid 70 is formed in the airtight chamber 10, the above-mentioned direct forming device of polycrystalline silicon further includes a plasma strengthening auxiliary device 50, which includes an induction coil 51 (induction coil) and a radio frequency power supply. 52 [radio frequency source], wherein the induction coil 51 is provided in the airtight chamber 10 and outside the nozzle mouth of the plasma spray gun 40 to strengthen the ionization of the plasma forming gas and sprayed silicon powder, so that the silicon liquid 7 0 The droplets are more dispersed into atomic groups and contain a large amount of ionized gas, and become a method of forming polycrystalline silicon by electrical destruction enhanced vacuum plasma spraying (Plasma Enhanced Vacuum Plasma Spray, PEVPS). In order to make the formed silicon liquid 70 have a better adhesion to the substrate 60, the stage 20 is connected to a bias power source 22 in the polycrystalline silicon direct forming device. The bias power source 22 may be a radio frequency power source (RF) or a single power source. The pulsed power is pulsed, so that the silicon liquid 70 has a better adhesion on the substrate 60. The polycrystalline silicon 71 formed according to the present invention can be used in a variety of different industries, such as semiconductors, photovoltaics, or solar cells. In order to make the polycrystalline silicon 71 have better quality [hidden hydrogen in the grain boundary of the polycrystalline silicon], the direct forming device of the polycrystalline silicon of the present invention It also contains an auxiliary gas introduction device 11 for transferring hydrogen atom-containing 591130 Case No. 89112049 V. Description of the invention (6) Auxiliary gas t such as hydrogen (H2), ammonia (NH3), methane (CH4) or silane (siH4, si lane) and other gases] are introduced into the airtight chamber 10 to improve the quality of polycrystalline silicon. In addition, depending on the degree of industrial utilization, silicon powder is doped with group 丨 丨 丨 elements (such as Ga, Ιη) or group V Element [such as ρ] to form polycrystalline silicon called P-type or type II without purification, and may even be doped with a group element (such as h ', cd) or a group element (such as s, Se, Te) Polycrystalline silicon of impure d η type is formed. spi 4 日 Η Α ^ ^ 解 疋 The foregoing preferred embodiment is used as an illustration of the present invention and is not intended to limit Tai Shuang, 4 straight r * ㈤ 疋 The present invention 'The scope of protection of the present invention is attached as the following As defined by the scope of the patent application, I τ is subject to the essence of the present invention, and any changes and modifications made by those skilled in the art without departing from the scope and scope of the present invention are deemed to be < range.

Page 10 591130 Case No. 89112049 Brief description of the modified drawing [Schematic description] Figure 1: Schematic cross-sectional view of the polycrystalline silicon direct forming device of the present invention; Figure 2a: According to the direct forming method of the polycrystalline silicon of the present invention, a substrate with VPS spraying schematic diagram; and FIG. 2b: According to the direct formation method of polycrystalline silicon according to the present invention, the direct formation of polycrystalline fragments on a substrate is not intended. [Illustration of drawing number] 10 Airtight chamber 11 Auxiliary gas introduction device 20 Carrier 21 Temperature control device 22 Bias power supply

30 Air extraction device 40 Plasma spray gun 41 Cathode 42 Anode 43 Gas introduction device 44 Silicon powder introduction device 50 Plasma auxiliary strengthening device 51 Induction coil 5 2 Radio frequency power supply 60 Substrate 7 0 Fine silicon liquid 71 Polycrystalline silicon

Page 11

Claims (1)

^ 1130 r—Japanese chrome inflammation, patent application scope, and then directly form polycrystalline silicon. The reading device mainly includes: an airtight chamber, which is used to block the external gas; the carrier, which is set in the airtight chamber, For placing the substrate, the stage is provided with a temperature control device to regulate the temperature of the substrate at 500 ~ 800. 〇; air extraction device, used to control the pressure of the airtight chamber below 丨 00T〇rr; at least one plasma spray grab, the plasma spray grab has a cathode, anode f, gas introduction device and silicon powder at the nozzle An introduction device in which an arc is formed between the cathode and the anode, and the gas introduction device is used to provide a plasma-forming gas to drive the stone powder through the arc; an auxiliary gas introduction device is used to introduce an auxiliary gas containing hydrogen atoms into the gas An airtight chamber; and a plasma enhanced auxiliary device including an induction coil and a radio frequency power source, wherein the induction coil is disposed in the airtight chamber and outside the nozzle mouth of the plasma spraying to enhance the ionization of the plasma to form a gas and Sprayed silicon powder. The direct-forming device for polycrystalline syphon according to item 6 of the patent application patent further includes a bias power source connected to the carrier. 8. The direct-forming device for polycrystalline silicon according to item 7 of the scope of the patent application, wherein the bias power source is a RF power source or a pulse power source. 2. The direct-forming device for polycrystalline silicon according to item 6 of the scope of the patent application, wherein the plasma spray grab includes a plutonium moving device for moving the plasma spray grab. 10. The direct-forming device for polycrystalline silicon according to item 6 of the scope of the patent application, wherein the plasma nozzle has a chirped DC power source to connect the cathode 591130 _ Case No. 89121049 Sixth, the scope of patent application is amended and anode. 11. The direct-forming device for polycrystalline silicon according to item 6 of the scope of the patent application, wherein the plasma spray gun has a high-frequency AC power source to connect the electrodes of the plasma spray gun. Page 14