TWI377173B - Method for manufacturing crystalline silicon - Google Patents

Description

1377173 IX. Description of the invention: [Technical field to which the invention pertains] Technical field

The present invention relates to a polycrystalline silicon film suitable for a thin film transistor (TFT) used in a liquid crystal display (LCD) 'Organic Light Emitting Display (OLED). The manufacturer, more specifically, relates to a method for producing a polycrystalline germanium film which is formed by a metal-induced crystallization method and which prevents metal contamination during formation of a TFT multi-junction film to improve the characteristics of the TFT. [Prior Art] The TFT is roughly classified into an amorphous germanium TFT and a multi-junction TFT. The characteristics of TFT

Evaluation of the value of electronic mobility. Since the electron mobility of the amorphous germanium TFT is about 15 lcm2/Vs', the electron mobility of the multijunction TFT is about l〇〇cm2/vs, so the high performance LCD should adopt a polycrystalline germanium TFT. The polycrystalline germanium TFT is formed by depositing an amorphous germanium on a transparent substrate such as glass or quartz to form a gate oxide film and a gate electrode, and then implanting a dopant into the source and the drain to form an insulating layer. production. 2〇 When manufacturing a polycrystalline germanium TFT, the main procedure is a step of polycrystallizing a film of amorphous germanium. In particular, it is preferred to lower the crystallization temperature. When the crystallization temperature is very south, when a TFT is manufactured, a glass substrate having a low melting point cannot be used, and the manufacturing cost of the TFT is greatly increased. The possibility of using such a glass substrate is considered. Recently, various steps of forming a polycrystalline thin film at a low temperature and a short time 5 C S have been proposed. The Excimer Laser Crystallization method uses a method of instantaneously irradiating a laser to melt an amorphous crucible and recrystallizing it, thereby preventing damage to the glass substrate caused by rapid heating, and having crystallinity of polycrystalline germanium. Excellent advantages. However, there are disadvantages such as reduced reproducibility and complicated equipment structure. The rapid heat treatment method utilizes an IR bulb to rapidly heat-treat the amorphous crucible, which has the advantages of high production speed and low production cost, and has the disadvantages of thermal impact caused by rapid heating and deformation of the glass substrate. The Metal Induced Crystallization (MIC) method applies a metal catalyst such as Νι, Cu, or A1 to an amorphous yttrium, and the method of crystallization at a low temperature has the advantage of being crystallizable at a low temperature, but has a leakage current. The disadvantage of a substantial increase in the amount of metal contained in the activation zone. The Metal Induced Lateral Crystallization (MILC) method is developed to prevent the metal contamination caused by the MIC method, and the metal catalyst is vapor-deposited in the source/drain region, and M〗c is preferentially induced. This is used as a seed crystal to grow the polycrystal enthalpy in the activation region of the lower portion of the gate. The ΜIL C method has the advantage that the metal contamination is less than the MIC method in the laterally grown crystallization region, but there is still a problem of leakage current. The occurrence of leakage current causes a problem of a change in the voltage of the data charged by each pixel of the display (LCD or the like), and the characteristics of the entire display are lowered. Thus, the metal introduction during TFT fabrication has the advantage of lowering the crystallization temperature of the amorphous germanium, and the advantages of the glass substrate can be used. Conversely, there is a disadvantage of reducing the characteristics of the TFT due to metal contamination, so the metal catalyst is introduced into the amorphous state. When 矽1377173 film, the adjustment of the introduction amount is very important. That is, in order to lower the crystallization temperature, when a large amount of metal catalyst is introduced, serious problems such as metal contamination occur. In order to prevent the problem of such metal contamination, when a very small amount of metal catalyst is introduced, the crystallization temperature for the purpose of introducing the metal catalyst is not achieved. 5 As a result, it is preferable to introduce a small amount of metal catalyst as much as possible and to lower the crystallization temperature.

In general, when a TFT is produced, a method of introducing a metal catalyst onto an amorphous germanium film is mainly a sputtering method, a spin coating method, or the like, and in particular, based on the easiness of the metal coating process, etc., a key-off method is mainly used. However, in the conventional sputtering method, the amount of the metal catalyst introduced onto the amorphous germanium film cannot be adjusted to a small amount. For example, when the metal catalyst is applied by sputtering, if the coating amount is as small as possible, the coating speed and the coating time must be kept as small as possible. However, if the coating speed and the coating time are in a very small range, there is a problem that it is extremely difficult to maintain the coating conditions constant. SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention has an object of providing a method for reducing crystallization temperature and minimizing metal contamination when crystallization of ruthenium by metal induced crystallization. A method of manufacturing a polysilicon which can improve TFT characteristics. In order to achieve the above object, the method for producing a polycrystalline silicon of the present invention has the following steps: (a) supplying a source gas containing a metal to an amorphous crucible; and (b) adjusting at least one of an adsorption pressure, an adsorption time, and an adsorption temperature. a predetermined amount of source gas is adsorbed onto the amorphous germanium; (c) removing the source gas that is not adsorbed onto the amorphous germanium in (b); (d) supplying the auxiliary gas to the adsorbed source (a) reacting the source gas adsorbed onto the amorphous stone with the auxiliary gas, and finally adsorbing a predetermined amount of the metal to the amorphous stone; (7) adsorbing the metal Amorphous stone heat treatment. In order to achieve the above object, the method for producing a polycrystalline silicon of the present invention has the following steps: (a) supplying a source gas containing a metal to an amorphous crucible by adjusting at least one of adsorption, force, and adsorption temperature, a predetermined amount The source gas is adsorbed onto the amorphous stone; (c) the source gas which is not adsorbed onto the amorphous stone in the above (8) is removed; and (4) the amorphous germanium adsorbed with the source gas is heat-treated. The source gas may contain any one or two or more of Ni, A, Ti, Ag, Au, Co, Sb, Pd, and Cu. The aforementioned source gas may be either Ni(cp)2 or Ni(dmamb)2. The auxiliary gas may contain a reducing gas such as H2 or NH3; an oxidizing gas such as 〇2, n2〇, H2〇, or ozone; or an inert gas such as Ar or N2. The adsorption temperature can be controlled at a normal temperature to 25 (rC2 range). In the above (b), the source gas can be adsorbed onto the amorphous crucible in a state where the coverage is less than 丨. In the above (f), the heat treatment temperature can be 4〇〇S7〇(rc, heat treatment time may be 1 to 10 hours, the heat treatment environment is an inert gas environment which may contain Ar, Ne, He, helium gas. In the above (d), the heat treatment temperature may be 4〇〇 To 7〇〇, the heat treatment time can be 1 to 10 hours, the heat treatment environment can be an inert gas environment containing Ar, Ne, He, N2 gas; 〇2, N2〇, H2〇, ozone and other oxidizing gas 1377173 In the reducing gas environment such as HNH3, the inventors of the present invention understand the aforementioned conventional method: the result of solving this problem, focusing on the method of chemically adsorbing the metal catalyst for finely adjusting the metal concentration of the guide:: The second feature of the present invention is that the chemical method is to use a chemical adsorption method to introduce a small amount of metal catalyst into the 韭曰^ non-day. In the sun, here, suck Department

Refers to the phenomenon that gases, liquid molecules, atoms, ions, etc. adhere to the surface. At this time, the method for producing the polycrystalline stone of the present invention is the following method, which can appropriately adjust the amount of metal adsorbed onto the amorphous film and reduce the amount of the metal. The crystallization temperature at the time of crystallization of amorphous austenite, and prevention of metal contamination to improve the characteristics of the polycrystalline slab TFT. 15 [Embodiment]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail. First, in the first embodiment of the present invention, a method of forming a polycrystalline tantalum film by heat-treating the metal onto the film of amorphous steel is described. First, a glass substrate on which an amorphous germanium film is formed is prepared and placed in a chamber where a metal adsorption process is performed. Here, in the case of an LCD or the like, the glass substrate corresponds to a TFT substrate on which a TFT is formed. After disposing the glass substrate, the chamber is evacuated by a vacuum pump so that the basic pressure in the chamber is about 100 mTorr. (S) 9 1377173

The source gas (metal organic compound) corresponding to the metal raw material adsorbed onto the amorphous film is supplied to the amorphous germanium film. Since the metal organic compound is generally present in a solid or liquid form at normal temperature, the metal organic compound is heated and gasified at a temperature higher than normal temperature. In this case, the gold 5 organic compound may contain any one or more of Ni, A, Ti, Ag, Au, Co, Sb, Pd, and Cu. In the case where the metal organic compound used in the present invention contains metallic nickel, Ni (cp) 2 [Di(cyclopentadienyl) nickel (II)); nickel (Nickel〇ce ne) )] or Ni (dmamb) 2[1-dimethylamine-2-methyl-2-butanolate] ° in the source gas supply step 'for the source The gas is smoothly supplied to the amorphous film (that is, the mobility of the Titch source gas), and the carrier gas can be supplied at the same time. Any one or two or more of Ar, Ne, He, and N2 may be used as the carrier gas. However, when the movement rate of the source gas is sufficient, the carrier gas may not be used. The source gas (metal organic compound) supplied by the carrier is adsorbed onto the amorphous germanium film. For example, when Ni (cp) 2 or Ni (dmamb) 2 is used as the source gas, the metal organic compounds are directly adsorbed onto the amorphous film. In the present invention, the metal substrate is allowed to adhere to the amorphous germanium film formed on the glass substrate by the standby of the glass substrate in a gas atmosphere in a gas atmosphere containing a metal compound. This process is a chemical adsorption process in which a metal of a metal organic compound (e.g., nickel) is chemically adsorbed onto a crucible of an amorphous germanium film. However, in the actual adsorption process, there is also a process of physically absorbing the metal to the amorphous germanium film. The metal adsorbed by the material 10 1377173 can also exert a catalytic action for lowering the crystallization temperature of the ruthenium. The amount of adsorbed organometallic compound (adsorption concentration) is directly affected by the gas pressure (adsorption pressure) in the chamber, the time during which the pressure can be maintained (adsorption time), and the temperature of the amorphous tantalum film (adsorption temperature). Therefore, when the adsorption pressure, the adsorption time, and the adsorption temperature are appropriately controlled, the adsorption concentration can be finely adjusted.

First, the adsorption pressure can be controlled to adjust the adsorption concentration of the organometallic compound. Since the adsorption pressure is directly related to the source gas flow supplied to the amorphous tantalum film, when the supply flow rate of the source gas is reduced, the adsorption pressure can be reduced, whereby the adsorption concentration can be reduced. On the other hand, when the supply flow rate of the source gas is increased, the adsorption concentration can be increased. Further, the total pressure of the gas flowing into the chamber and the total flow rate of the gas discharged from the chamber can be adjusted to control the adsorption pressure. For example, by adjusting the difference between the total flow rate of the gas flowing into the chamber and the total flow rate of the gas discharged from the chamber, the adsorption pressure is controlled, whereby the adsorption concentration can be controlled. Of course, the foregoing method also includes a method of closing the chamber and controlling the adsorption pressure when the indoor portion reaches a predetermined adsorption pressure. The adsorption concentration of the organometallic compound can also be adjusted by controlling the adsorption time. For example, when the adsorption time for maintaining the adsorption pressure is shorter, the adsorption concentration of the metal organic compound can be further reduced. 20 When controlling the adsorption temperature, the adsorption concentration can be adjusted. Since the predetermined heat energy is required during the adsorption process, the adsorption concentration of the metal organic compound can be reduced when the adsorption temperature is lowered. However, when the adsorption temperature is very low, there is no possibility of adsorption at the beginning. When the adsorption temperature is very high, the adsorbed metal organic compound can be separated from the amorphous germanium film by 11 C S ) 1377173. It is preferred to maintain the temperature of the amorphous tantalum film at a predetermined adsorption temperature before starting the adsorption step. The adsorption temperature is maintained at 100 to 25 Torr. (The range is preferably within the range of the source gas. When the heat is required for all of the suctions (for example, when it is adsorbed at room temperature), the adsorption temperature is controlled to normal temperature.

On the other hand, when the crystallized crucible is applied to a TFT or the like, it is necessary to minimize the adsorption concentration in order to prevent deterioration of the characteristics of the semiconductor or the display due to metal contamination. Therefore, it is necessary to adjust the metal to be adsorbed onto the thin crucible of the amorphous crucible in a state of less than one atomic layer. Here, 10 or less than one atomic layer means that the metal catalyst cannot completely cover the entire area of the amorphous germanium film with one atomic layer, that is, the metal is not continuously adsorbed onto the entire amorphous germanium film, but is adsorbed everywhere. The situation (coverage, 〗). At this time, the metal adsorption device 1 of the present invention controls at least one of the adsorption pressure, the adsorption time, and the adsorption temperature, and the adsorption temperature can be finely adjusted, so that the adsorption concentration is adjusted to 15 Lang as the above coverage is less than 1 The advantages.

Next, in the adsorption step, the source gas (metal organic compound) which is not adsorbed onto the amorphous tantalum film is discharged (rinsed) from the chamber to be removed. The source gas discharged during this process contains the first adsorbed onto the amorphous germanium film, but the degree of adsorption is weak (for example, physically adsorbed to the source gas 20 on the amorphous germanium film), and is separated from the amorphous germanium film. Source gas. When this step is completed, the process of adsorbing the source gas (metal compound) onto the amorphous germanium film is completed. At this time, it is possible to use a carrier gas for smoothly moving the source gas to flow, and it is possible to use the source gas. Then, the process of adsorbing the metal onto the amorphous germanium film is such that the metal organic compound adsorbed to the 12 1377173 amorphous film is reacted with the auxiliary gas to remove the metal organic compound and the organic compound.

. Therefore, the assist gas is supplied to the amorphous film which is adsorbed with the metal organic compound. The auxiliary gas thus supplied is reacted with the metal organic compound adsorbed onto the amorphous germanium film, and finally, the metal is adsorbed onto the amorphous germanium film. For example, if the source gas Ni (cp) 2 reacts with the auxiliary gas, the cp component is removed, and Ni is adsorbed onto the amorphous film (ie, 'Ni ( cp ) 2+H2—Ni+mCnH2n+2] In the present invention, the assist gas may be a reducing gas such as ruthenium 2 or NH3, an oxidizing gas such as 02, N 2 〇, H 2 〇 or ozone, or an inert gas such as Ar or N 2 . 10 Next, the by-product gas generated as a result of the reaction between the source gas and the assist gas is discharged (empty) from the chamber. At the end of this step, the process of adsorbing the metal onto the amorphous germanium film is completed. At this time, a carrier gas stream for smoothly moving the source gas can be used to discharge the by-product gas. Next, a process of heat-treating a metal-doped amorphous ruthenium film to produce a multi-fine crystal film will be described. This process is based on the metal induced crystallization method described above, and the crystallization temperature of the ruthenium is reduced to the extent that the glass substrate can be used by the metal catalyst adsorbed onto the amorphous film. The heat treatment of the present invention is carried out by waiting for the amorphous metal film adsorbed on the metal to stand by in the chamber maintained at the predetermined heat treatment temperature. Here, there are cases where the chamber is the same as the chamber in the adsorption step of the metal organic compound, and there are cases where the chamber is different. That is, there are cases where both adsorption and heat treatment processes are carried out in one (four)', and the adsorption and heat treatment processes are carried out in separate chambers, respectively. 13 The heat treatment temperature is preferably in the range of 400 to 700 〇c. When the heat treatment temperature is very low, since the crystallization time is increased, the problem of productivity (handling amount) must be considered. When the heat treatment temperature is very high, the problem of deformation of the glass substrate must be considered. The heat treatment time is preferably in the range of 丨 to (7) hours. When the heat treatment time is very short, the problem of poor crystallization of the amorphous ruthenium must be considered. When the heat treatment time is very long, the productivity problem must be considered. The environment during heat treatment is preferably an inert gas atmosphere. Here, the inert gas used contains Ar, Ne, He, & gas. As a result, in the first embodiment, the process of forming the polysilicon thin film for TFT is completed. In the present invention, the metal concentration introduced to lower the crystallization temperature is minimized, and there is an advantage that the metal contamination of the TFT can be remarkably reduced, the performance of the TFT can be improved, and the characteristics of the semiconductor or display using ktft can be obtained. In the second embodiment of the present invention, a method of forming a polycrystalline germanium film by heat-treating the metal organic compound onto the amorphous germanium film will be described. In the second embodiment of the present invention, the steps of adsorbing the metal organic compound onto the amorphous thin layer are the same as those in the first embodiment. That is, the second embodiment of the present invention is a method in which a metal organic compound is adsorbed onto an amorphous germanium film in the same manner as in the first embodiment, that is, a method of forming a polycrystalline germanium film by heat treatment. In the second embodiment of the present invention, the detailed description of the process similar to that of the first embodiment will be omitted. Here, only the differences in the heat treatment stage will be described. In the heat treatment stage of the second embodiment, the basic concept and the heat treatment conditions are substantially the same as those of the first embodiment. However, in the heat treatment step of the second embodiment, the process of removing the metal organic compound adsorbed onto the amorphous germanium film and the process of crystallizing the amorphous rock are carried out. Therefore, the relationship between the second sinus 0 environment and the first embodiment is different from that of the first embodiment. In the second embodiment, the auxiliary gas used in the 5th 丨 形态 在 can be used in the heat treatment step to promote From the metal organic compounds to ', the reaction of organic δ. In the second embodiment of the present invention, one of the reducing gases such as (4) 2, ν2〇, Η2ο, ozone, and the like, and 2, and 3, etc., may be used in the processing step. Of course, in the second embodiment, as in the first embodiment, an inert gas atmosphere containing VIII, Ne'He, and Ν2 gas may be used in the heat treatment step. 1〇 In the second solid surface towel, any one of a mixed gas atmosphere of an oxidizing gas and an inert gas and a mixed gas of a reducing gas and an inert gas may be used in the step of reducing the temperature. When the mixed gas is used in the heat treatment step of the second embodiment, the ratio of the mixed gas is preferably in the range of 5 Torr to 99% by inert gas. In the heat treatment step of the second embodiment, the heat treatment outside the gas atmosphere 15 is preferably the same as the temperature range of the first embodiment. Thus, in the second embodiment, the process of forming the polysilicon film for TFT is completed. As in the first embodiment, the metal concentration introduced to lower the crystallization temperature is reduced as much as possible, and the metal contamination of the TFT can be remarkably reduced, and the performance of the TFT and the characteristics of the semiconductor or display using the TFT can be improved.

According to the present invention, since it can be applied to a substrate of a large surface, the productivity of a flat panel display such as LC D can be increased, and the production cost can be reduced. Therefore, the industrial applicability of the present invention is extremely high. In the meantime, the present invention has been described in a number of preferred embodiments, and it is to be understood that various modifications and changes can be made without departing from the scope and spirit of the invention as disclosed in the appended claims. Corrected. [Circular Simple Description] (None) [Main Component Symbol Description] (None)

16 (S )

Claims (1)

Patent Application No. 96,150,242, filed on February 10, 2011, the scope of the patent application is replaced by the tenth, the scope of the patent application: <〇/year of the month 〖0 day revision 1. A method for manufacturing polycrystalline germanium, comprising the following steps: (a) Supplying a source gas containing a metal to the amorphous crucible; (b) adsorbing a predetermined amount of source gas to the amorphous crucible by adjusting at least one of adsorption pressure, adsorption time, and adsorption temperature; (c) Removing the source gas that is not adsorbed onto the amorphous germanium in the above (b); (d) supplying the assist gas to the amorphous germanium adsorbed with the source gas; (e) by adsorbing to the aforementioned amorphous germanium The source gas is reacted with the auxiliary gas, and finally the amorphous germanium adsorbs a metal having a coverage of less than 1; and (1) the amorphous germanium adsorbed with the metal is heat-treated. 2. A method for producing a polycrystalline silicon comprising the steps of: (a) supplying a source gas containing a metal to an amorphous crucible; (b) adjusting at least one of an adsorption pressure, an adsorption time, and an adsorption temperature; a metal having an adsorption coverage of less than 1 on the amorphous side; (c) removing a source gas that is not adsorbed onto the amorphous germanium in (b), and (d) an amorphous state to which the source gas is adsorbed矽 Heat treatment. 3. The method for producing a polycrystalline silicon according to claim 1 or 2, wherein the source gas contains any one or more of Ni, A, Ti, Ag, Au'Co, Sb, Pd and Cu. 4. The method for manufacturing a polycrystalline silicon according to item 3 of the patent application, wherein the patent application scope of the aforementioned Patent Application No. 1 377 173, No. 96,150,242 is replaced by the patent of the present invention, and the source gases are Ni(cp) 2 and Ni (dmamb) 2 Any of them. 5. The method of producing a polycrystalline silicon according to the first aspect of the invention, wherein the auxiliary gas comprises a reducing gas of H2. 6. The method for producing polycrystalline silicon according to claim 1 or 2, wherein the adsorption temperature is from room temperature to 250 °C. 7. The method for producing a polycrystalline silicon according to claim 1, wherein in the above (f), the heat treatment temperature is 400 to 700 ° C, and the heat treatment time is 1 to 10 hours. 8. The method for producing polycrystalline silicon according to item 2 of the patent application, wherein in the above '10 (d), the heat treatment temperature is 400 to 700 ° C, and the heat treatment time is 1 to 10 hours. 18