KR100337491B1 - apparatus of Chemical Vapor Deposition - Google Patents

Abstract

Located in the upper chamber portion of the dome-shaped upper chamber portion having a semicircle or a constant angle and the shower head portion and the upper chamber in which a reaction gas for thin film deposition is ejected in a straight line or radially according to the shape of the upper chamber portion And a heat energy source for forming a lower chamber portion and a thin film which are sealed through an o-ring, and a gas for suppressing a reaction gas from flowing from a heater portion formed in the center of the lower chamber bottom surface and a lower end of the heater portion is blown out. Provided is a chemical vapor deposition apparatus comprising a nozzle portion. According to the present invention, the reaction gas supplied for thin film deposition is sprayed linearly or radially on the wafer surface to form a thin film having excellent uniformity characteristics, and the reaction product inside the chamber is also significantly reduced.

Description

Apparatus of Chemical Vapor Deposition

The present invention relates to a chemical vapor deposition apparatus for depositing a thin film on a wafer surface, and more particularly, to an improved chemical vapor deposition apparatus that is excellent in the uniformity characteristics of the thin film and can minimize the reaction product in the chamber.

As the size of semiconductor devices becomes smaller and lighter, design-rules are greatly reduced, and RC delay due to wiring has emerged as an important factor for determining the operation speed. As a result, a multi-layer wiring structure has been put to practical use, and in the case of a highly integrated circuit device such as a microprocessor, the number of metal wiring layers required is increasing from the existing 2-3 layers to 4-6 layers, and with higher integration in the future It is expected that more wiring layers will be used if going forward.

Tungsten excellent in step coverage and excellent conductivity is mainly used as the wiring layer, and as a method for depositing such tungsten, a CVD thin film using chemical vapor deposition (CVD) is commonly used. It is used.

Looking at the field to which the chemical vapor deposition apparatus is applied as follows.

First, a wiring device having electrical conducting characteristics such as a polysilicon layer film, copper (Cu), titanium / titanium nitride (Ti / TiN) film, aluminum (Al), tungsten (W), and W-Six Applied to manufacturing.

Second, the present invention is applied to the deposition of an oxide film used as an insulating film between conductive material films such as SiO ₂ films using various chemicals.

Third, high dielectric thin films such as Si ₃ N ₄ , Ta ₂ O ₅ , BST, PZT, and Al ₂ O ₃ used as dielectric materials in memory devices such as DRAM (Dynamic Random Access Memory) or Flash memory. Applied to the deposition.

Fourth, in the subsequent patterning process to manufacture a semiconductor device, in order to alleviate the step difference on the surface of the semiconductor substrate, an oxide film doped with impurities such as phosphorous or boron may be used. It is applied to the oxide film forming process for forming.

Meanwhile, chemical vapor deposition for forming wirings, oxide films, and the like on a semiconductor substrate is performed by loading batches of wafers or wafers one by one, and then processing the wafers one by one. There is a single wafer type. The single-wafer type chemical vapor apparatus has various advantages in terms of process, but there is a disadvantage that the uniformity characteristic of the thin film depends on the structure of the chemical vapor apparatus.

As such, conventional chemical vapor deposition apparatuses have poor uniformity characteristics of the deposited thin film, and unwanted reaction products are formed in the reaction chamber. In order to remove the reaction products in the chamber, the cleaning cycle of the chamber is shortened and the process is delayed. Such reaction products act as particles that degrade the reliability of the semiconductor device, thereby reducing the overall yield. There is a problem of deterioration.

It is therefore an object of the present invention to provide an improved chemical vapor deposition apparatus which can solve the above-mentioned conventional problems.

Another object of the present invention is to provide an improved chemical vapor deposition apparatus capable of improving the uniformity characteristics of the deposited thin film.

Another object of the present invention is to provide an improved chemical vapor deposition apparatus capable of minimizing a reaction product inside a chamber.

Another object of the present invention is to provide an improved chemical vapor deposition apparatus which can increase the overall yield.

Another object of the present invention is to provide an improved chemical vapor deposition apparatus that can solve the problem of shortening the cleaning cycle of the chamber.

SUMMARY OF THE INVENTION In order to achieve the above objects, the present invention provides a chemical vapor deposition apparatus used for thin film deposition for forming wiring or insulating film on a wafer surface, comprising: a dome-shaped upper chamber portion having a semicircle or a curved surface at a predetermined angle; A shower head part disposed in the upper chamber part, and the reaction gas for thin film deposition is ejected in a straight line or a radial shape according to the shape of the upper chamber part; A lower chamber portion sealed through the upper chamber and an O-ring; A heater unit which is a heat energy source for forming a thin film and is formed in the center of the lower chamber bottom; It provides a chemical vapor deposition apparatus comprising a nozzle portion for ejecting a gas for suppressing the reaction gas flows from the lower end of the heater.

1 is a cross-sectional view of a chemical vapor deposition apparatus according to a preferred embodiment of the present invention.

Figure 2 shows a three-dimensional perspective view of the upper chamber of the chemical vapor deposition apparatus.

3 shows a cross-sectional view of the upper chamber of the chemical vapor deposition apparatus.

4 shows a bottom plan view of the upper chamber of the chemical vapor deposition apparatus.

Figure 5 shows a three-dimensional perspective view of the lower chamber of the chemical vapor deposition apparatus.

6 is a sectional view of a lower chamber of the chemical vapor deposition apparatus.

7 shows a bottom plan view of the lower chamber of the chemical vapor deposition apparatus.

8 is a sectional view of a heater part of the chemical vapor deposition apparatus.

9 is a plan view of an internal heater part of the heater part of the chemical vapor deposition apparatus.

10 is a plan view of an external heater unit of the heater unit of the chemical vapor deposition apparatus.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view of a chemical vapor deposition apparatus according to a preferred embodiment of the present invention.

Referring to the drawings, the chemical vapor deposition apparatus is largely composed of an upper chamber, a shower head formed in the upper chamber, a lower chamber, a heat source formed in a predetermined region of the lower chamber, and the like. It is explained in detail by these.

Figure 2 shows a three-dimensional perspective view of the upper chamber of the chemical vapor deposition apparatus, Figure 3 shows a cross-sectional view of the upper chamber of the chemical vapor deposition apparatus, Figure 4 shows a bottom plan view of the upper chamber of the chemical vapor deposition apparatus. .

Referring to the drawings, the side wall 3 of the upper chamber having a semicircle or an angled curved surface, the first showerhead 3a and the second showerhead 3b having a predetermined shape of holes, and gas from the outside Gas line 5 is shown.

At this time, the number of holes, the diameter, and the arrangement of the holes formed in the first shower head 3a and the second shower head 3b are realized in the best form to improve the uniformity characteristics of the thin film. That is, the size and number of holes of the first showerhead 3a and the second showerhead 3b are differently configured according to the characteristics of the thin film to be deposited, and the first and second showerheads 3a and 3b are formed of the thin film. It is desirable to form at an optimal distance where uniformity characteristics can be optimal. In addition, in order to make the optimal distance between the first shower head 3a and the second shower head 3b, it is possible to form the plate of the first shower head 3a or the second shower head 3b to be movable. desirable. Since the flow of gas injected from the shower head is radial according to the shape of the straight or the upper chamber, the uniformity characteristic of the thin film deposited on the wafer surface is improved.

Nickel is preferably used as the material for manufacturing the first and second shower heads 3a and 3b. However, the thin film material to be deposited, that is, the type of remote plasma cleaning gas, is used. Therefore, it may be formed of pure aluminum or aluminum oxide (oxidized aluminum).

Looking at the configuration of the first / second shower head (3a, 3b) that the gas flows from the outside in more detail as follows.

When the gas is supplied from the gas line 5, after passing through the first shower head 3a having a predetermined number of holes, the firstly passed gas is formed at a predetermined distance interval. Passes through the showerhead 3b plate. The number of holes formed in the plate of the second showerhead 3b has a larger number of holes than the number of holes formed in the plate of the first showerhead 3a.

Therefore, a plurality of holes are formed so that the reaction gases flowing from outside may reach the surface of the wafer where the reaction gases are loaded or radially depending on the shape of the upper chamber, thereby improving the uniformity characteristics of the deposited film. Can be. In addition, it is possible to deposit a thin film having excellent characteristics in terms of stoichiometer of the thin film deposited on the surface. In addition, it is possible to greatly improve the loading effect in a region having a high pattern density compared to a planner without a pattern in the wafer.

Figure 5 shows a three-dimensional perspective view of the lower chamber of the chemical vapor deposition apparatus, Figure 6 shows a cross-sectional view of the lower chamber of the chemical vapor deposition apparatus, Figure 7 shows a bottom plan view of the lower chamber of the chemical vapor deposition apparatus. .

Referring to the drawings, a groove 7-1 is formed in the upper end of the chamber for the O-ring to maintain the vacuum sealing (Vacuum Sealing), the cylindrical vertical chamber having a constant capacity from the top of the chamber The side wall 21 is formed. A taping chamber 9 is formed to be inclined in a tapered type having a predetermined angle from a predetermined height of the lower chamber bottom portion, and a heater 11 serving as a heat source to be proposed in the present invention is formed at the center of the chamber bottom. The hole 11-1 of a certain form is formed in the part in which the is to be located. One side of the cylindrical chamber is formed with a slot 13 for loading / unloading a wafer for processing. In addition, an asymmetric vacuum guide 15 is formed on the cylindrical chamber sidewall 21 to improve the uniformity characteristic of the thin film by radially inducing the vacuum in the chamber and the flow of the process gas. In addition, a vacuum port 17 associated with the vacuum guide 15 is formed on the opposite side of the portion where the wafer is loaded / unloaded, and a state inside the lower chamber is formed in a predetermined region of the side wall 21 of the lower chamber. The gate port 19 for measuring is formed.

In addition, the inner vacuum plate 23 and the outer vacuum plate 25 are formed to maintain the inside of the chamber in a vacuum state and induce a gas flow during the process, and nitrogen for suppressing the inflow of the reaction gas from the lower end of the heater. (N ₂ ) The nozzle 27 is formed. In addition, a nitrogen gas slot is formed on the internal vacuum plate to adjust the flow path of the nitrogen nozzle 27.

In this case, in order to maintain a vacuum state between the upper chamber and the lower chamber, a single O-ring may be used in addition to the double O-ring 7 described above.

FIG. 8 is a sectional view of a heater part of the chemical vapor deposition apparatus, FIG. 9 is a plan view of an internal heater part of the heater part of the chemical vapor deposition device, and FIG. 10 is a plan view of an external heater part of the heater part of the chemical vapor deposition device. .

Referring to the drawings, the internal heater 29 has a diameter slightly smaller than the diameter of the entire wafer 33, and functions to control the overall temperature inside the chamber. Molybdenum (Mo) or ceramic may be used as the heating element material of the internal heater 29.

The heater block functioning as the external heater 31 is formed so as to be located outside about 2 to 10 mm of the outer diameter of the wafer, and the heat loss is very large because it is close to the side wall of the chamber. Therefore, in order to maintain the temperature of the wafer surface uniformly, the temperature of the external heater 31 must be controlled. As the heating element material of the external heater 31, molybdenum (Mo) or ceramic (ceramic) may be used. The heater block, which functions as the external heater 31 that surrounds the heating element and transfers heat generated from the heater to the susceptor 33, is formed of a ceramic material such as aluminum nitride (AlN). It is desirable to. In this case, irregularities are formed on the surface of the susceptor 33 in a predetermined pattern in order to prevent slippage of the loaded wafer.

In addition, the lift pin for loading / unloading the wafer 33 on the heater is preferably formed of a ceramic material such as Al ₂ O ₃ .

On the other hand, in order to control the temperature inside the chamber, the inner heat coupler 35 and the outer heat coupler 37 are formed at the heater center and the edge, respectively.

11 shows a rear plan view of an external heater of the chemical vapor deposition apparatus.

Referring to the drawings, the drawing shows a heating element drawing of the valve portion in which the wafer is in / out, and as the slot valve is opened / closed, heat loss to the outside becomes greater than that of other portions. Therefore, the uniformity property of the thin film deposited on this portion is deposited thinner than other regions. Therefore, in order to preserve the heat loss of this part, the thickness of the heating element is made thinner than other parts (reference 'A') to give the same electric resistance. have.

As described above, when the heater unit of the chemical vapor deposition apparatus according to the present invention forms an isosceles triangle based on the diameter of the slot valve around the heater center, the heater is thinly formed. . In addition, the temperature range that the heater unit can control is about 300 ℃ to 850 ℃. In addition, the heater is a heat source for providing a heat activation energy provided for the formation of a thin film to be implemented in the present invention includes a heating element for converting the electrical energy supplied from the outside into thermal energy, the ceramic surrounding the heating element consisting of (ceramic) material (AlN, Al ₂ O _3, etc.), being present at a fixed location inside the thermal couple heater that can measure temperature to control the internal temperature, and the thermal couple It is formed in the required number so that uniformity can be formed under optimum conditions.

In addition, when the surface on which the wafer is placed on the heater is called a susceptor, the configuration of the susceptor is characterized by forming a susceptor guide on which the wafer is directly seated and a lift pin for moving the wafer.

Then, a method of manufacturing various thin films of a semiconductor device using the chemical vapor deposition apparatus having the above configuration will be described with reference to various embodiments.

First, when a thin film is to be manufactured using one kind of reaction gas, the reaction gas is introduced through the shower heads 3a and 3b.

For example, when SiH ₄ gas or Si ₂ H ₆ gas is introduced into the chamber and the reaction temperature in the chamber is maintained at 450 ° C. to 650 ° C., amorphous silicon (LPMO) or low pressure chemical vapor deposition (LPCVD) is used. A polycrystalline silicon film is deposited.

Alternatively, after introducing SiH ₄ gas or Si ₂ H ₆ gas into the chamber, the reaction temperature in the chamber is maintained at 450 ° C. to 650 ° C., and the pressure is controlled to 10 E-5 Torr or less to selectively form hemispherical silicon grains. do.

On the other hand, when a thin film is to be formed using two or more kinds of reaction gases, the first reaction gas is introduced first and then the second reaction gas is introduced or two kinds of reaction gases are introduced at the same time.

For example, when forming a nitride film (Si3N4) using NH ₃ gas and SiH ₂ Cl ₂ gas, N ₂ O gas is introduced first, and then NH ₃ gas and SiH ₂ Cl ₂ gas are continuously introduced. The nitride film is formed by maintaining the reaction temperature in the chamber at 500 ° C. to 800 ° C. and maintaining the pressure at 300 Torr or lower.

Alternatively, when a nitride film is formed using NH ₃ gas and SiH ₄ gas, N ₂ O gas is introduced first, and then the NH ₃ gas and SiH ₄ gas are continuously introduced at the same time, and the reaction temperature in the chamber is 500. The temperature is maintained at 800 ° C. and the pressure is maintained at 300 Torr or lower to form a nitride film.

Alternatively, when a nitride film is formed using NH ₃ gas and SiCl ₄ , N ₂ O gas is introduced first, and then the NH ₃ gas and SiCl ₄ are introduced at the same time, and the reaction temperature in the chamber is 800 ° C. at 800 ° C. When the temperature is maintained at 占 폚 and the pressure is maintained at 300 Torr or lower, a nitride film is formed.

Alternatively, when a nitride film is formed using NH ₃ gas and SiCl ₆ gas, N ₂ O gas is introduced first, and then the NH ₃ gas and SiCl ₆ gas are introduced at the same time, and the reaction temperature in the chamber is 500. The temperature is maintained at 800 ° C. and the pressure is maintained at 300 Torr or lower to form a nitride film.

On the other hand, in the case of forming an oxide film (SiO 2) using O ₂ gas and SiH ₄ gas, O ₂ gas is introduced first, and then O ₂ gas and SiH ₄ are continuously introduced at the same time, and the reaction temperature in the chamber is 300 ° C. At 800 ° C. and at a pressure of 300 Torr or lower to form an oxide film.

Alternatively, when an oxide film is formed using N ₂ O gas and SiH ₂ Cl ₂ gas, N ₂ O gas is introduced first, and then N ₂ O gas and SiH ₂ Cl ₂ gas are continuously introduced at the same time, and When the reaction temperature is maintained at 300 ° C. to 800 ° C. and the pressure is maintained at 300 Torr or less, an oxide film is formed.

Alternatively, when an oxide film is formed using N ₂ O gas and SiH ₄ gas, N ₂ O gas is introduced first, and then N ₂ O gas and SiH ₄ gas are continuously introduced at the same time, and the reaction temperature in the chamber is 300. When the temperature is maintained at 800 ° C. and the pressure is maintained at 300 Torr or less, an oxide film is formed.

In order to form a CVD thin film by introducing three or more kinds of reactive gases, one or two reactive gases may be introduced first and then the remaining gases may be introduced to form the CVD thin film.

As described above, in the present invention, in implementing a chemical vapor deposition apparatus for depositing a thin film on the wafer surface, by forming the upper chamber in a domed shape having a curved or constant angle, the reaction gas supplied for the thin film deposition is a wafer surface It is induced to be sprayed in a straight or radial to improve the uniformity characteristics of the thin film.

In addition, by forming a heater to control the temperature inside the chamber in a double structure, the heat loss from the side wall of the chamber is minimized to improve the uniformity characteristics of the thin film.

In addition, by forming the heating element thickness of the external heater to be thinner than other parts, the uniformity characteristic of the thin film deposited on the wafer surface is improved, and the stoichiometric characteristic of the deposited film quality is also greatly improved.

In addition, nitrogen gas is introduced through the nitrogen nozzle to suppress the inflow of the reaction gas to the lower end of the heater, thereby reducing the reaction product in the chamber, thereby extending the cleaning cycle of the chamber and improving the loading effect.

What has been described above is only one embodiment for carrying out the chemical vapor deposition apparatus according to the present invention, the present invention is not limited to the above-described embodiment, but deviates from the gist of the present invention claimed in the following claims. Without departing from the art, any person having ordinary skill in the art may understand that changes can be made.

Claims (11)

In a chemical vapor deposition apparatus used for thin film deposition for forming wiring or insulating film on the wafer surface: A domed upper chamber portion having a semicircle or a curved surface at an angle; A shower head part disposed in the upper chamber part, and the reaction gas for thin film deposition is ejected in a straight line or a radial shape according to the shape of the upper chamber part; A lower chamber portion sealed through the upper chamber and an O-ring; A heater unit which is a heat energy source for forming a thin film and is formed in the center of the lower chamber bottom; And a nozzle unit through which a gas is ejected to suppress the reaction gas from flowing from the lower end of the heater unit. The method of claim 1, wherein the lower chamber is a cylindrical vertical type having a constant capacity from the top of the chamber, the bottom chamber is formed to be inclined in a tapered type having a constant angle from a certain height to the bottom of the chamber bottom, one side of the chamber for the process A slot for loading / unloading a wafer is formed, and an asymmetric vacuum guide is formed on the sidewall of the chamber to maintain a vacuum inside the chamber and to induce a radial gas flow. And a nitrogen gas slot for forming a flow path, and a vacuum port is formed on the opposite side of the portion where the wafer is loaded / unloaded. The method of claim 1, wherein the shower head portion and the first shower head through which the reaction gas supplied from the outside primarily; In order to improve the uniformity characteristic of the deposited thin film, the first showerhead is formed at a predetermined distance from the first showerhead, and has a larger number of holes than the first showerhead and passes through the first showerhead. The chemical vapor deposition apparatus, characterized in that consisting of a second showerhead passing secondarily. 4. The chemical vapor deposition apparatus according to claim 3, wherein the first shower head or the second shower head is movably formed so as to maintain a constant distance between the first shower head and the second shower head. . The chemical vapor deposition apparatus according to claim 1, wherein the heater unit comprises a heating element for converting electrical energy supplied from the outside into thermal energy. 6. The chemical vapor deposition apparatus according to claim 5, wherein the heating element of the heater is formed of molybdenum (Mo) or ceramic (Sic). The chemical vapor deposition apparatus according to claim 1, wherein the heater part is made of aluminum nitride (AlN). The chemical vapor deposition apparatus according to claim 1, wherein the showerhead is formed of pure aluminum or aluminum oxide, depending on the material of nickel or the thin film to be deposited. The chemical vapor deposition apparatus according to claim 1, wherein a single or double O-ring is formed between the upper chamber portion and the lower chamber portion to maintain the vacuum between the upper chamber portion and the lower chamber portion. The chemical vapor deposition apparatus according to claim 1, wherein the heating element thickness of the external heater is made thinner than other portions. The chemical vapor deposition apparatus according to claim 1, wherein the heater is formed of a dual structure of an external heater and an internal heater to preserve the amount of heat lost from the side wall of the chamber.