KR20020017633A - A chemical vapor deposition apparatus - Google Patents

Abstract

PURPOSE: A chemical vapor deposition apparatus is provided to improve process uniformity and a quality of a semiconductor device by improving scattering of reaction gas inside a process chamber so that a uniform thin film is formed on a wafer, and to increase productivity by increasing the number of wafers that can be simultaneously processes. CONSTITUTION: A vertical diffusion furnace forms a thin film on the semiconductor wafer. A gas line(160) supplies reaction gas to the vertical diffusion furnace. A line injector sprays the reaction gas to the upper portion of the diffusion furnace, connected to the gas line. A middle injector sprays the reaction gas to an intermediate portion of the diffusion furnace which is located under the spray position of the long injector, connected to the gas line.

Description

Chemical vapor deposition apparatus {A CHEMICAL VAPOR DEPOSITION APPARATUS}

The present invention relates to a chemical vapor deposition apparatus, and more particularly to a chemical vapor deposition apparatus for improving the distribution of the reaction gas in the process chamber.

In general, in the fabrication of semiconductor devices, high integration and miniaturization, high capacitance in a narrow space (capacitance) is required. In order to increase the capacitance, a method of increasing capacitance using a condenser area and a dielectric in a semiconductor device has been researched and developed.

There is a process called HSG (Hemi Spherical Grain) to increase the capacitance by increasing the area of the double capacitor. This is a process of increasing the area of the capacitor by configuring the lower storage node of the capacitor in the semiconductor device convexly convex in a flat shape.

There are two types of apparatus for forming an HSG, a wafer type sheet and a batch type wafer.

1 is a schematic view showing a batch type vertical CVD apparatus for simultaneously processing a plurality of wafers. Referring to FIG. 1, a conventional vertical CVD apparatus 10 includes a reaction chamber 12 using a quartz tube and an injector nozzle 14 connected to a gas supply line 20 to supply a process gas into the chamber. Equipped with. Process conditions affecting the uniformity of the process in the CVD apparatus include temperature, pressure, wafer spacing, and gas flow rate. Properly adjusting these variables can improve the uniformity of the film quality deposited on the wafer 50. In particular, in the case of the vertical diffusion furnace, since the supply of the reaction gas by the diffusion of the gas has a large influence on the process progress, an efficient gas supply method can improve the uniformity of the process.

Existing CVD apparatus 10 having the above-described structure is supplied so that the process gas is diffused in the upper portion of the reaction chamber 12 through a single injector nozzle 14, and is exhausted through the lower gas discharge line 18 In a way.

As a result, the SIH4 gas for growing HSG is sufficient at the upper end, but as the gas is discharged downward, the concentration distribution of the gas gradually decreases. As a result, the supply of the reaction gas through the single injector nozzle 14 brings about a difference in concentration according to the upper and lower regions of the process chamber 12, which in turn lowers the uniformity of the thin film. That is, the conventional vertical CVD apparatus 10 has a problem of lowering the uniformity of the thin film due to the difference in density concentration according to the position of the reaction gas supplied to the process chamber 12 during the process.

The present invention is to solve such a conventional problem, the object of the new type of chemistry to improve the uniformity of the process by supplying the reaction gas so that the distribution of the reaction gas concentration according to the position in the process chamber is uniform It is to provide a vapor deposition apparatus.

1 is a schematic view of a conventional vertical CVD apparatus;

2 is a cross-sectional view showing a vertical chemical vapor deposition apparatus according to an embodiment of the present invention;

3 is a block diagram showing a gas flow of the vertical chemical vapor deposition apparatus according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

110: process tube 116: exhaust pipe

118: flange 120: heater

130: boat 142: first injector

144: second injector 146: third injector

160: gas line 170: regulating valve

According to a feature of the present invention for achieving the above object, the chemical vapor deposition apparatus includes a vertical diffusion path for forming a thin film on the surface of the semiconductor wafer; A gas line for supplying a reaction gas to the diffusion path; A long injector connected to the gas line and configured to inject a reaction gas into an upper portion of the diffusion path; And a middle injector connected to the gas line for injecting the reaction gas into an interruption portion of the diffusion path below the injection position of the long injector.

In the present invention as described above may further include a short injector for injecting the reaction gas to the lower portion of the diffusion path that is lower than the injection position of the middle injector.

According to the present invention having the above-described configuration, a process gas is injected by upper, middle, and lower portions of a process tube through a long / middle / short injector to stabilize the distribution of the gas supplied for each position of wafers located in the process tube. The uniformity of the thin film deposited on the was to be improved.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to FIGS. 2 to 3. In addition, in the drawings, the same reference numerals are denoted together for components that perform the same function.

2 is a cross-sectional view showing a vertical chemical vapor deposition apparatus according to an embodiment of the present invention. Figure 3 is a block diagram showing the gas supply of the vertical chemical vapor deposition apparatus according to an embodiment of the present invention.

The present invention improves the uniformity of the reaction gas by injecting the reaction gas to various points of the process chamber through the injectors of various lengths in the process conditions of the chemical vapor deposition apparatus for forming a thin film on the semiconductor wafer.

2 to 3, the vertical CVD apparatus 100 is largely comprised of a process tube 110, a heater 120, a boat 130, and a plurality of injectors 142, 144, and 146.

The process tube 110 has a flange 118. The process tube 110 includes a first injector 142, a second injector 144, and a third injector 146 for injecting a reaction gas.

The first injector 142 is longer than the second injector 144 and the third injector 146 to inject the reaction gas into the upper portion of the process tube 110.

The second injector 144 has an intermediate length between the first injector 142 and the third injector 146 to inject the reaction gas into the middle portion of the process tube 110. The third injector 146 has a shorter length than the first and second injectors 142 and 144, and the third injector 146 injects a reaction gas into a lower portion of the process tube.

Meanwhile, the first, second, and third injectors 142, 144, and 146 are respectively connected to branch lines 162, 164, and 166 branched from the gas line 160 for supplying a reaction gas. In addition, in order to separately adjust the amount of the reaction gas supplied from the first, second, and third injectors 142, 144, and 146, a control valve 170 is preferably provided on each branch line 162, 164, 166.

As such, the supply of the reaction gas is performed at three points (up, middle, and bottom of the reaction tube) through the first, second, and third injectors 142, 144, and 146, and thus, according to the upper, middle, and lower regions of the process tube 110. The reaction gas concentration difference can be kept uniform. Therefore, a thin film can be uniformly deposited on the wafer. On the other hand, the reaction gas in which a predetermined film quality is deposited on the surface of the wafer is exhausted through the exhaust pipe 116 of the flange 118 to the exhaust line.

For example, in the present embodiment, only three injectors 142, 144, and 146 are installed in the process tube 110, but four or five or more injectors may be installed depending on the length of the process tube 110 and the number of wafers. It is preferable that they have different lengths.

In the above, the configuration and operation of the chemical vapor deposition apparatus according to the present invention is shown in accordance with the above description and drawings, but this is just described, for example, and various changes and modifications can be made without departing from the technical spirit of the present invention. Of course.

According to the present invention, by forming a uniform thin film on the surface of the wafer by improving the distribution of the reaction gas in the process chamber as a process condition, there is an effect that can improve the uniformity of the process and the quality of the semiconductor device. In addition, since the distribution of the process gas in the chamber is maintained uniformly, the number of wafers that can be processed simultaneously in the apparatus increases, thereby improving the productivity of the apparatus.

Claims (2)

A vertical diffusion path for forming a thin film on the surface of the semiconductor wafer; A gas line for supplying a reaction gas to the diffusion path; A long injector connected to the gas line and configured to inject a reaction gas into an upper portion of the diffusion path; And a middle injector connected to the gas line and configured to inject a reaction gas into an interruption portion of the diffusion path below the injection position of the long injector, thereby improving distribution of the reaction gas in the diffusion furnace. Chemical vapor deposition apparatus. The method of claim 1, And a short injector for injecting a reaction gas into a lower portion of the diffusion path below the injection position of the middle injector.