TW202226347A - Method for manufacturing semiconductor film by using sputtering technology - Google Patents

Abstract

The present invention mainly discloses a method for manufacturing a semiconductor film by using sputtering technology, which is characterized in that the gas ratio between a reactive gas and a working gas introduced into a sputtering chamber is controlled between 15% and 25% under the condition of a fixed total gas flow rate. In this way, when the gas ratio is controlled between 15% and 25%, an atom from the target material and an atom of the reaction gas will react in a Metastable mode to form a compound composing a semiconductor thin film, thereby accelerating the coating rate of the semiconductor thin film on a substrate. Therefore, the method of the present invention has the potential to replace the conventional MOCVD technology and/or MBE technology, and thus is widely used in the fabrication of LED devices.

Description

Method for fabricating semiconductor thin films using sputtering technology

The present invention relates to the technical field of semiconductor thin film manufacturing, and more particularly, to a method for manufacturing semiconductor thin films using sputtering technology.

LED is a widely used light-emitting element at present. It has the advantages of small size and long service life, so it is widely used in human daily life. As LED backlight sources are widely used in displays, tablet computers, and smart phones, the size of LED electronic components is required to be further scaled down to the micron size. Mini LED, also known as "sub-millimeter light-emitting diode", was first proposed by EPISTAR Corporation. The diagonal length of the die is between 50 microns and 60 microns. In recent years, Micro LED (Micro LED) has become a new generation of display technology. By further miniaturizing the LED die, the diagonal length of the die is less than 50 microns. The technology of driving light-emitting separately realizes the individual addressing of the picture element of each LED die.

Metal Organic Chemical Vapor Phase Deposition (MOCVD) is a crystal growth method, which has been widely used. Used in the fabrication of light-emitting diodes (LEDs), lasers (Laser), transistors (Transistor), and solar cells (Solar cell). Taking the production of gallium nitride (GaN) thin films as an example, the precursors and dopants are fed into a heated high-temperature reaction chamber by reactive gases, and nitrogen (N) atoms and gallium (Ga) atoms are heated to produce chemical reactions, and The growth of lattices on the substrate finally forms a thin film with neatly arranged atoms. The deposition method of this thin film is also called epitaxy.

In addition to MOCVD, Molecular Beam Epitaxy (MBE) is also often used in the fabrication of LED components. It is known that the industry is currently using a lot of MOCVD technology in the manufacture of LED components. Unfortunately, when making undoped gallium nitride (Undoped GaN, u-GaN) with a thickness of about 2 μm, the low growth rates of MOCVD and MBE are obviously uneconomical. On the other hand, the industry is committed to directly growing aluminum nitride and/or gallium nitride thin films on silicon carbide (SiC) substrates to reduce the manufacturing cost of LED devices and solve the problem of poor heat dissipation of traditional sapphire substrates. However, when silicon carbide is used as the substrate of the LED element, a layer of aluminum nitride (AlN) must be grown between the N-type gallium nitride and the silicon carbide substrate as a buffer layer. In the process of making the aluminum nitride (AlN) buffer layer, a large amount of trimethylaluminum (TMAl) gas is required as the source of aluminum components, and hydrogen, a large amount of ammonia gas (NH ₃ ) and nitrogen gas (N ₂ ) are also required as fillings gas.

It can be seen from the above description that when applied to the fabrication of semiconductor thin films such as GaN and AlN, the conventional MOCVD technology and/or MBE technology still has room for further improvement. In view of this, the inventor of the present case has made great efforts to research and invent, and finally developed and completed a method of producing a semiconductor thin film using sputtering technology of the present invention.

The main purpose of the present invention is to provide a method for fabricating a semiconductor thin film using sputtering technology, which is characterized in that, under the condition of a fixed total gas flow rate, a reaction gas and a working gas flowing into a sputtering chamber are The gas ratio is controlled between 15% and 25%. In this way, when the gas ratio is controlled between 15% and 25%, an atom from the target material and an atom of the reaction gas will react in a metastable mode (Metastable mode) A compound of a semiconductor thin film is used to accelerate the coating rate of the semiconductor thin film on a substrate. Therefore, the method of the present invention has the potential to replace the conventional MOCVD technology and/or MBE technology, and thus is widely used in the fabrication of LED devices.

In order to achieve the above object, the present invention proposes an embodiment of the method for fabricating a semiconductor thin film using sputtering technology, which includes the following steps:

(1) respectively placing a target and a substrate on a first stage and a second stage in a sputtering chamber of a sputtering equipment;

(2) Passing at least one reaction gas and a working gas into the sputtering chamber according to a total gas flow, wherein the total gas flow is between 135 sccm and 165 sccm;

(3) Adjust a fixed sputtering power of the sputtering equipment between 90W and 110W, and adjust a gas ratio between the reactive gas and the working gas under the condition of fixing the total gas flow so that the Gas ratio between 15% and 25%; and

(4) Under the condition that a process temperature in the sputtering chamber is between 600° C. and 800° C., a semiconductor film is plated on the surface of the substrate 3 .

In the foregoing embodiments of the present invention of the method for fabricating a semiconductor thin film using sputtering technology, under the condition that the gas ratio is controlled between 15% and 25%, the An atom of the target reacts with an atom of the reactive gas in a metastable mode to form a compound for composing the semiconductor thin film.

In the above-mentioned embodiment of the method for fabricating a semiconductor thin film using sputtering technology of the present invention, when the underlying material is a sapphire substrate (Sapphire), a silicon substrate, a silicon carbide substrate, or a glass substrate, it is formed on the The semiconductor thin film on the underlying material is a buffer layer, and the buffer layer is made of any one of the following materials: undoped gallium nitride (Undoped GaN, u-GaN), zinc oxide (ZnO) or nitride Aluminum (AlN) layer.

In the above-mentioned embodiment of the method for fabricating a semiconductor thin film using sputtering technology of the present invention, when the underlying material is a buffer layer, the semiconductor thin film formed on the underlying material is an N-type gallium nitride ( n-type gallium nitride, n-GaN) layer.

In the above-mentioned embodiments of the method for fabricating a semiconductor thin film using sputtering technology of the present invention, when the underlying material is an N-type gallium nitride layer, the semiconductor thin film formed on the underlying material is an active layer .

In the above-mentioned embodiment of the method for fabricating a semiconductor thin film using sputtering technology of the present invention, when the underlying material is an active layer, the semiconductor thin film formed on the underlying material is a P-type gallium nitride ( p-type gallium nitride, p-GaN) layer.

<The present invention>

S1-S4: Steps

1: Sputtering equipment

10: Sputtering chamber

101: The first stage

102: Second stage

B1: Target

B2: Substrate

BL: buffer layer

NS: N-type gallium nitride layer

AL: Active layer

PS: P-type GaN layer

SL: semiconductor material layer

1 shows a flow chart of a method for fabricating a semiconductor thin film using sputtering technology according to the present invention;

FIG. 2 shows a schematic diagram of a process for forming a buffer layer on a substrate using the method of the present invention;

Figure 3 is a graph showing the data of nitrogen (N ₂ ) concentration versus deposition rate of semiconductor thin films;

FIG. 4 shows a schematic diagram of a process for forming a semiconductor material layer on a buffer layer using the method of the present invention;

5 shows a schematic diagram of a process for forming another semiconductor material layer on a buffer layer by using the method of the present invention;

6 shows a schematic diagram of a process for forming another semiconductor material layer on a buffer layer by using the method of the present invention;

7 shows a side cross-sectional view of a buffer layer and a semiconductor material layer plated on a substrate by the method of the present invention;

Fig. 8 shows the transmission electron microscope (Transmission electron microscopy, TEM) picture of this buffer layer and this semiconductor material layer;

FIG. 9 shows an XRD pattern measured from a GaN layer using an X-ray diffraction (XRD) analyzer operating in wide angle diffraction (WAG) mode; and

Figure 10 shows an XRD pattern measured from a ZnO layer using an X-ray diffraction analyzer operating in wide angle diffraction mode.

In order to more clearly describe a method for fabricating a semiconductor thin film using sputtering technology proposed by the present invention, preferred embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a flow chart of a method for fabricating a semiconductor thin film by sputtering according to the present invention. As shown in FIG. 1 , the method for producing a semiconductor thin film using sputtering technology of the present invention mainly includes the following steps:

Step S1: respectively placing a target and a substrate on a first stage and a second stage in a sputtering chamber of a sputtering apparatus;

Step S2: passing at least one reactive gas and one working gas into the sputtering chamber according to a total gas flow, wherein the total gas flow is between 135 sccm and 165 sccm;

Step S3: Adjust a fixed sputtering power of the sputtering equipment to be between 90W and 110W, and adjust a gas ratio between the reactive gas and the working gas under the condition of fixing the total gas flow so that the Gas ratio between 15% and 25%; and

Step S4 : under the condition that a process temperature in the sputtering chamber is between 600° C. and 800° C., a semiconductor film is plated on the surface of the substrate.

A method for fabricating a semiconductor thin film using sputtering technology of the present invention will be described below in conjunction with the relevant figures. FIG. 2 shows a schematic diagram of a process of forming a buffer layer on a substrate by using the method of the present invention. As shown in FIG. 2 , a target B1 and a substrate B2 (ie, the substrate) are respectively placed on a first stage 101 and a second stage 102 in a sputtering chamber 10 of a sputtering apparatus 1 . above (ie, step S1). Next, at least one reactive gas and one working gas are passed into the sputtering chamber 10 according to a total gas flow, wherein the total gas flow is between 135 sccm and 165 sccm (ie, step S2 ). Continue, adjust a fixed sputtering power of the sputtering equipment to be between 90W and 110W, and adjust a gas ratio between the reactive gas and the working gas under the condition of fixing the total gas flow so that the The gas ratio is between 15% and 25% (ie, step S3). Finally, in the sputtering chamber 10 When the process temperature is between 600°C and 800°C, a semiconductor film is plated on the surface of the substrate B2 (ie, the substrate) as a buffer layer BL (ie, step S4 ).

Taking the manufacture of LED devices as an example, the substrate B2 can be a sapphire substrate (Sapphire), a silicon substrate, a silicon carbide substrate, or a glass substrate, and the buffer layer can be made of undoped gallium nitride (Undoped GaN, u-GaN), Zinc Oxide (ZnO) or Aluminum Nitride (AlN). Taking gallium nitride as the manufacturing material of the buffer layer as an example, the reactive gas and the working gas are nitrogen (N ₂ ) and argon (Ar) respectively, and the target material is a gallium nitride target or a gallium target. In an experimental example, the total gas flow was controlled at 150 sccm, and a gas ratio between the reaction gas and the working gas was controlled between 15% and 25%. Under this process condition, an atom (Ga) from the target material 2 reacts with an atom (N) of the reactive gas in a metastable mode to form a BL film for forming the buffer layer. compound (ie, GaN).

FIG. 3 is a data plot of nitrogen (N ₂ ) concentration versus deposition rate of a semiconductor thin film. It can be seen from Figure 3 that under the condition of fixed sputtering power and total gas flow of 100W and 150sccm, respectively, when the concentration of nitrogen exceeds 25% (that is, the gas ratio of the aforementioned reactive gas and working gas), the coating of gallium nitride will The rate tends to be flat, that is, it enters the coating stage of the nitrided state. On the other hand, at a fixed sputtering power and total gas flow of 100 W and 150 sccm, respectively, when the nitrogen concentration exceeds between 15% and 25%, gallium atoms and nitrogen atoms are in a metastable mode ( Metastable mode) reacts into a gallium nitride film plated on the surface of the substrate B2. It can be seen from FIG. 3 that the coating rate of gallium nitride in the metastable state is significantly greater than that of gallium nitride in the nitrided state.

More specifically, when zinc oxide (ZnO) is used as the material for producing the buffer layer, the reactive gas and the working gas are oxygen (O ₂ ) and argon (Ar), respectively, and the target is a zinc target. In addition, when aluminum nitride (AlN) is used as the material for producing the buffer layer, the reaction gas and the working gas are nitrogen (N ₂ ) and argon (Ar), respectively, and the target is an aluminum target.

Continuing, FIG. 4 shows a schematic diagram of a process for forming a semiconductor material layer on a buffer layer using the method of the present invention. As shown in FIG. 4, a target B1 is placed on a first stage 101 in a sputtering chamber 10 of a sputtering apparatus 1, and a substrate B2 covered with a buffer layer BL is placed in the sputtering chamber on a second stage 102 within 10 . It should be understood that, with respect to the target material B1, the buffer layer BL covering the substrate B2 is a so-called bottom layer. Taking the manufacture of LED components as an example, in the case where the underlying material is a buffer layer BL covering the substrate B2, a semiconductor material layer, such as a N-type gallium nitride (n-type gallium nitride, n-GaN) layer NS.

Moreover, FIG. 5 shows a schematic diagram of a process of forming another semiconductor material layer on a buffer layer by using the method of the present invention. As shown in FIG. 5 , a target B1 is placed on a first stage 101 in a sputtering chamber 10 of a sputtering apparatus 1 , and is sequentially covered with a buffer layer BL and an N-type gallium nitride (n-type gallium nitride). A substrate B2 of the GaN) layer NS is placed on a second stage 102 in the sputtering chamber 10 . At this time, the N-type gallium nitride layer NS is a so-called underlayer with respect to the target B1. Taking the manufacture of LED devices as an example, in the case that the underlying material is an N-type gallium nitride layer NS, an active layer AL, that is, multiple quantum well layers, can be successively formed on the underlying material by the method of the present invention. .

On the other hand, FIG. 6 shows a schematic diagram of a process of forming another semiconductor material layer on a buffer layer by using the method of the present invention. As shown in Figure 6, a target B1 is placed in a sputtering equipment A first stage 101 in a sputtering chamber 10 of the on a second stage 102 in the sputtering chamber 10 . At this time, the active layer AL is a so-called primer with respect to the target B1. Taking the manufacture of LED components as an example, in the case where the underlying material is the active layer AL, a semiconductor material layer, such as a p-type gallium nitride (p-type gallium nitride (p-type gallium nitride) can be successively formed on the underlying material by the method of the present invention. -type gallium nitride, p-GaN) layer PS.

Experimental example

7 shows a side cross-sectional view of a buffer layer and a semiconductor material layer plated on a substrate using the method of the present invention. As shown in FIG. 7 , in the experimental example, a buffer layer BL and a semiconductor material layer SL are sequentially plated on the surface of a substrate B2 by using the method of the present invention. Moreover, FIG. 7 specifically indicates that the buffer layer BL is a ZnO layer, and the semiconductor material layer SL is a GaN layer. Further, FIG. 8 shows a transmission electron microscope (TEM) image of the buffer layer and the semiconductor material layer. Also, FIG. 9 is an XRD pattern measured from the GaN layer using an X-ray diffraction (XRD) operating in a wide-angle diffraction (WAG) mode, and FIG. 10 is a An XRD pattern measured from the ZnO layer by X-ray diffraction (XRD) in Diffraction (WAG) mode.

It should be known that GaN is a hexagonal wurtzite structure, and ZnO is a hexagonal lattice material. Since the X-ray diffraction analyzer operates in the wide-angle diffraction mode, Fig. 9 shows that the diffraction peak signal of GaN appears around 17.5°, while the diffraction peak signal of ZnO appears around 34.5°. one Therefore, experimental data show that the method of the present invention can indeed sequentially coat the ZnO buffer layer and the GaN semiconductor material layer on the substrate B2 at a high coating rate.

Thus, the above has completely and clearly explained a method for fabricating a semiconductor thin film using sputtering technology disclosed in the present invention. It must be emphasized that the above detailed description is directed to the specific description of the feasible embodiments of the present invention, but the embodiments are not intended to limit the scope of the patent of the present invention. Any equivalent implementation or modification that does not depart from the technical spirit of the present invention, All should be included in the scope of the patent in this case.

S1-S4: Steps

Claims (6)

A method for fabricating a semiconductor thin film using sputtering technology, comprising the following steps: (1) respectively placing a target and a substrate on a first stage and a second stage in a sputtering chamber of a sputtering equipment; (2) Passing at least one reaction gas and a working gas into the sputtering chamber according to a total gas flow, wherein the total gas flow is between 135 sccm and 165 sccm; (3) Adjust a fixed sputtering power of the sputtering equipment between 90W and 110W, and adjust a gas ratio between the reactive gas and the working gas under the condition of fixing the total gas flow so that the Gas ratio between 15% and 25%; and (4) When a process temperature in the sputtering chamber is between 600° C. and 800° C., a semiconductor thin film is plated on the surface of the underlying material. The method for fabricating a semiconductor thin film using sputtering technology as claimed in claim 1, wherein, under the condition that the gas ratio is controlled between 15% and 25%, an atom from the target reacts with the One of the atoms of the gas reacts in a metastable mode to form a compound for composing the semiconductor thin film. The method for fabricating a semiconductor thin film using sputtering technology as claimed in claim 1, wherein when the underlying material is a sapphire substrate (Sapphire), a silicon substrate, a silicon carbide substrate, or a glass substrate, it is formed on a The semiconductor thin film on the underlying material is a buffer layer, and the buffer layer is made of any one of the following materials: undoped gallium nitride (Undoped GaN, u-GaN), zinc oxide (ZnO) or nitride Aluminum (AlN). The method for fabricating a semiconductor thin film using sputtering technology as described in claim 1, wherein, when the underlying material is a buffer layer, the semiconductor thin film formed on the underlying material is an N-type gallium nitride ( n-type gallium nitride, n-GaN) layer. The method for fabricating a semiconductor thin film using sputtering technology as claimed in claim 1, wherein when the underlying material is an n-type gallium nitride (n-GaN) layer, it is formed on the underlying layer The semiconductor thin film above the object is an active layer. The method for fabricating a semiconductor thin film using sputtering technology as described in claim 1, wherein, when the underlying material is an active layer, the semiconductor thin film formed on the underlying material is a P-type gallium nitride ( p-type gallium nitride, p-GaN) layer.

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