KR200244729Y1 - Low pressure chemical vapor deposition equipment for semiconductor manufacturing - Google Patents

Abstract

The present invention relates to a low pressure chemical vapor deposition apparatus for manufacturing a semiconductor. In the related art, a gas exhausted due to an abnormal operation of an exhaust pump flows back into a reactor or a load lock chamber to contaminate a wafer. A load lock chamber equipped with a reactor and a wafer boat for loading or unloading wafers into the reactor, an exhaust pipe connected to the reactor and the load lock chamber, and a reactor connected to the exhaust pipe and the reactor and the load lock chamber. A low pressure chemical vapor deposition apparatus for manufacturing a semiconductor comprising an exhaust pump for exhausting an inside, the exhaust pipe further comprising a backflow prevention pipe, wherein the backflow prevention pipe includes a three-way valve installed at a branch point of the exhaust pipe, and the three-way valve. The pressure is composed of an on-off valve with a pressure sensor for controlling the opening and closing direction of the And to vary the opening and closing direction of the waste-way valve if the sensor detects a pressure of the gas backflow from the exhaust pump.

Thus, wafer contamination due to backflow of exhaust gas is prevented.

Description

Low Pressure Chemical Vapor Deposition Equipment for Semiconductor Manufacturing

The present invention relates to a low pressure chemical vapor deposition apparatus for semiconductor manufacturing, in which reverse flow of exhaust gas is prevented, and in particular, exhaust gas is introduced into a load-lock chamber or a reactor due to an abnormality of an exhaust system such as an exhaust pump. It is a low pressure chemical vapor deposition apparatus for semiconductor manufacturing to prevent backflow and contamination of a wafer.

Generally, chemical vapor deposition (CVD) is used to chemically react a reaction gas and a wafer surface to deposit a polysilicon film, a silicon oxide film, and a silicon nitride film on the wafer surface.

Chemical Vapor Deposition (CVD) is classified into various types according to generation pressure, excitation energy, and device type. Among them, low pressure chemical vapor deposition (LPCVD) or atmospheric pressure chemical chemistry is performed according to the difference in the production pressure in the reaction chamber. It is classified as Atomospheric Pressure CVD (APCVD).

Low pressure chemical vapor deposition (LPCVD) maintains the pressure of the reaction chamber under a pressure of 0.1 to 10 torr, then chemically reacts the reaction gas and the wafer to deposit on the surface of the wafer. Atmospheric pressure chemical vapor deposition (APCVD) is the pressure of the reaction chamber. Is maintained under atmospheric pressure, and then the reaction gas and the wafer are chemically reacted and deposited.

A deposition apparatus used for low pressure chemical vapor deposition (LPCVD) among these chemical vapor deposition (CVD) methods is shown in FIG.

As shown in FIG. 1, a conventional low pressure chemical vapor deposition apparatus for semiconductor manufacturing includes a reactor 1, a load lock chamber 2 installed at a lower end of the reactor 1, and the reactor 1 And exhaust parts 3 to 5 connected to the load lock chamber 2.

The reactor 1 is composed of an inner and an outer tube made of quartz, and a thin film is deposited by supplying a process gas including a deposit to be deposited on a wafer under low pressure.

The load lock chamber 2 is installed at the lower end of the reactor 1 to block the outside air to prevent the exposure of the wafer to the outside when the wafer is loaded and to deposit a natural oxide film on the wafer surface. A wafer boat is located that is loaded or unloaded into the furnace 1 to allow the process to proceed.

The exhaust parts 3 to 5 are reactors formed between the reactor 1 and the exhaust pump 5 to exhaust the gas, which has been completed in the reactor 1, by the exhaust pump 5. An exhaust pipe (3) and a load lock chamber exhaust pipe (4) formed between the load lock chamber (2) and the exhaust pump (5) to exhaust the inside of the load lock chamber (2) by the exhaust pump (5).

In the low pressure chemical vapor deposition apparatus for manufacturing a semiconductor having such a configuration, the exhaust of the reactor and the load lock chamber is as follows.

First, the load lock chamber 2 is loaded through the load lock chamber exhaust pipe 4 using an exhaust pump 5 to bring the pressure of the load lock chamber 2 to atmospheric pressure before loading the wafer into the reactor 1. The inside of the lock chamber 2 is evacuated to atmospheric pressure.

When the inside of the load lock chamber 2 is at atmospheric pressure, the wafer is driven upward by the wafer boat to be loaded into the reactor 1, and the process gas is supplied into the reactor 1 in a low pressure state to perform the deposition process. .

In this process, the pressure retention in the reactor 1 and the exhaust of the process gas after the reaction are performed by the reactor exhaust pipe 3 connected to the exhaust pump 5.

However, such a conventional low pressure chemical vapor deposition apparatus exhausts the outside air inside the load lock chamber by pumping an exhaust pump through the load lock chamber exhaust pipe, and maintains the inside of the reactor in which the process is being carried out at a low pressure state or after the reaction is completed. In the process of exhausting the exhaust pump by the exhaust pump through the reactor exhaust pipe, if the exhaust cannot be smoothly caused by external factors such as failure of the exhaust pump or momentary stoppage or power failure, the pressure is increased to the exhaust pump. Rather, the exhaust gas flows back into the reactor or load lock chamber at a relatively low pressure, contaminating the wafer located in the reaction chamber or the load lock chamber, and the reaction by-product attached to the inner wall of the exhaust line as the exhaust gas flows back. It is included in the exhaust gas flowing back to contaminate the wafer.

Therefore, the present invention was devised to solve the problems of the conventional low pressure chemical vapor deposition apparatus for semiconductor manufacturing, and prevents contamination of the wafer inside the reactor or the load lock chamber due to the inflow of the exhaust gas even if the problem of the exhaust occurs. Its purpose is to provide a low pressure chemical vapor deposition apparatus for semiconductor manufacturing.

Therefore, in order to achieve the above object, the present invention provides a load lock chamber equipped with a reactor under low pressure, a wafer boat for loading or unloading a wafer into the reactor, and an exhaust pipe connected to the reactor and the load lock chamber, respectively. And a low pressure chemical vapor deposition apparatus for manufacturing a semiconductor comprising an exhaust pump connected to the exhaust pipe and exhausting the reactor and the inside of the load lock chamber, the exhaust pipe further comprising a backflow prevention pipe, wherein the backflow prevention pipe includes the exhaust pipe. And a three-way valve installed at a branch point between the three-way valve and a pressure-opening valve equipped with a pressure sensor for controlling the opening and closing direction of the three-way valve, wherein the pressure sensor senses the pressure of the gas flowing back from the exhaust pump. To change the opening and closing direction of the valve, the backflow prevention pipe is further provided with a nitrogen gas supply pipe The non-return tube should be kept to a high-pressure state.

1 is a cross-sectional view of a conventional low pressure chemical vapor deposition apparatus for semiconductor manufacturing,

2 is a cross-sectional view of a low pressure chemical vapor deposition apparatus for manufacturing a semiconductor of the present invention.

* Brief description of the main parts of the drawings *

1: Reactor 2: Loadlock part

3: reactor exhaust pipe 4: rodlock chamber exhaust pipe

5: exhaust pump

101,102: non-return pipe 103,104: three-way valve

105,106,107: On-off valve 108,109: Nitrogen supply pipe

Hereinafter, a low pressure chemical vapor deposition apparatus for manufacturing a semiconductor according to the present invention will be described with reference to the accompanying drawings.

2 is a cross-sectional view of a low pressure chemical vapor deposition apparatus for semiconductor manufacturing according to the present invention, the low pressure chemical vapor deposition apparatus for semiconductor manufacturing according to the present invention is a process gas containing a deposit to be deposited on the wafer to deposit a thin film on the wafer under low pressure There is a reactor 1 composed of inner and outer tubes of quartz material supplied.

The reactor 1 has a reactor exhaust pipe (3a, 3b) connected to the exhaust pump (5) for exhausting the inside of the reactor (1), it is connected to the reactor exhaust pipe (3a, 3b) exhaust pump There is a first backflow prevention tube 101 for blocking the gas backflow in (5).

A three-way valve 103 is installed at branch points of the reactor exhaust pipes 3a and 3b and the first non-return pipe 101 to direct the flow of gas exhausted from the reactor 1 to the reactor exhaust pipe 3b. Continuously maintaining or blocking, and the first backflow prevention pipe 101 is further provided with a nitrogen gas supply pipe 108 to maintain the nitrogen gas in a high pressure state inside the first backflow prevention pipe 101. .

In addition, the first non-return valve 101 is provided with an opening / closing valve 106 and an opening / closing valve 105 with a pressure sensing sensor in the exhaust pump 5 direction, and then the opening / closing valve with the pressure sensing sensor ( 105 detects the pressure of the gas flowing back from the exhaust pump 5 to control the opening and closing direction of the three-way valve 103.

In addition, at the lower end of the reactor 1, there is a load lock chamber 2 which blocks outside air when the wafer is loaded or unloaded to exhaust the outside air so that a natural oxide film is not deposited on the wafer surface.

The load lock chamber 2 has one end connected to the load lock chamber exhaust pipes 4a and 4b for exhausting the gas in the load lock chamber 2 by the exhaust pump 5 and the load lock chamber exhaust pipes 4a and 4b. The second backflow prevention tube 102 is connected to the first backflow prevention tube 101.

The second backflow prevention pipe (102) is also provided with a nitrogen gas supply pipe (109) to maintain the high pressure state by the nitrogen gas inside the second backflow prevention pipe (102), and the load lock chamber exhaust pipes (4a, 4b) and A three-way valve 104 in which the flow direction of gas is controlled by the on / off valve 105 with the pressure sensing sensor is installed at the branch point of the second backflow prevention pipe 102, and the load lock chamber exhaust pipe 4 is provided. And an on / off valve 107 between the second backflow prevention pipe 102.

In the low pressure chemical vapor deposition apparatus according to the present invention having such a configuration, the exhaust gas is prevented from flowing back into the reactor or the load lock chamber as follows.

First, when the load lock chamber 2 is exhausted, the valves of the reaction furnace exhaust pipes 3a and 3b and the first backflow prevention pipe 101 are closed.

At this time, when the gas is not exhausted due to the abnormal operation of the exhaust pump 5 and flows back to the load lock chamber exhaust pipe 4b, the pressure sensor of the on-off valve 105 detects this and opens the on-off valves 105 and 107, respectively. 2 The nitrogen gas maintained at high pressure inside the backflow prevention pipe 102 pushes back the gas backflow, and at the same time, the load lock chamber exhaust pipe 4a blocks the opening and closing direction of the three-way valve 104, and the load lock chamber exhaust pipe 4b. Direction so that nitrogen gas maintained at a high pressure flows to the load lock chamber exhaust pipe 4b.

Therefore, the backflow gas is pushed toward the exhaust pump 5 by the nitrogen gas supplied at a high pressure from the second backflow prevention tube 102.

The exhaust of the reactor 1 is performed while the valves of the load lock chamber exhaust pipes 4a and 4b and the second backflow prevention pipe 102 are closed. When the gas flows back due to an abnormal operation of the exhaust pump 5, The pressure sensor of the on-off valve 105 detects this and opens the on-off valves 106 and 107, respectively, to push out the gas from which the high-pressure nitrogen gas flows back in the first backflow prevention pipe 101, and at the same time, the three-way valve 103 The opening and closing direction is changed from the reactor exhaust pipe 3a to the reactor exhaust pipe 3b so that the gas exhausted from the reactor 1 is blocked, and the nitrogen gas in the high pressure state of the first backflow prevention pipe 101 is momentarily The gas flowing back in the direction of the exhaust pump 5 is blown toward the exhaust pump 5.

As described above, the low pressure chemical vapor deposition apparatus for semiconductor manufacture according to the present invention has the advantage of preventing contamination of the wafer by preventing gas from flowing back into the reactor or the load lock chamber due to the abnormality of the exhaust system during the thin film deposition process. have.

Claims (1)

A load lock chamber equipped with a reactor under low pressure, a wafer boat for loading or unloading wafers into the reactor, an exhaust pipe connected to the reactor and the load lock chamber, a reactor connected to the exhaust pipe, and A low pressure chemical vapor deposition apparatus for manufacturing a semiconductor comprising an exhaust pump for exhausting the inside of the load lock chamber, the apparatus comprising: a backflow prevention pipe connected to the exhaust pipe; A three-way valve installed at a branch point of the backflow prevention pipe and the exhaust pipe; An opening / closing valve having a pressure sensor for controlling the opening / closing direction of the three-way valve; It comprises a nitrogen gas supply pipe connected to the backflow prevention pipe, the pressure sensor detects the pressure of the gas flow back from the exhaust pump to change the opening and closing direction of the throughway valve and at the same time nitrogen in the nitrogen gas supply pipe Low pressure chemical vapor deposition apparatus for semiconductor manufacturing characterized in that the gas is supplied.