KR200162754Y1 - Spreading tube for preventing natural oxide film - Google Patents

Abstract

The present invention relates to a diffusion path that prevents natural oxide film growth on a wafer by blocking external natural air inflow.

The present invention provides a diffusion tube 21 for forming a reaction chamber for performing a diffusion process, a first gas inlet 22 for supplying nitrogen gas or a reaction gas to the active tube in a predetermined direction, and formed around the tube. And a fork 28 for loading the diffusion process section composed of the heating oil 23 for heating to the process temperature, the boat 27 mounted with the wafer 26 into the diffusion process section, and an inertness on the wafer loaded into the diffusion tube. It is formed by the second gas introduction port 25 forming a gas atmosphere, and is formed around the passage in which the wafer is loaded in the intermediate region between the wafer loading part and the diffusion process part and the wafer loading part to convey the wafer along the loading path. In the chemical vapor deposition apparatus configured as a scavenger for exhausting the surplus gas remaining in the fine state remaining after reacting with the wafer, the scavenger includes: a third gas introduction port 24-2 for supplying nitrogen gas; 3rd gas In a gas and diffusion process of the component part for the excess gas to the scavenger (24-1) for the exhaust to the exhaust / off to block the external air inlet to prevent a native oxide film formed by including a diffusion from the inlet.

Description

Natural oxide film diffusion diffusion furnace.

1 is a conventional device,

2 is a device of the present invention.

* Explanation of symbols for main parts of the drawings

11,21: Diffusion tube 12,22: 1st gas inlet

13,23: Heating coil 14,24-1: Scavenger

15,25: second gas introduction port 16,26: wafer

17,27: boat 18,28: port

19,29 Passage 24-2: 3rd Gas Inlet

24-3: connector 24-4, 24-5: hall

The present invention relates to a diffusion path in a chemical vapor deposition apparatus, and more particularly to a natural oxide film diffusion diffusion path to suppress the production of natural oxide film growing on the wafer.

In general, chemical vapor deposition equipment which performs a chemical vapor deposition (CVD) process in a semiconductor device manufacturing process performs an actual diffusion process in a diffusion furnace.

1 is a conventional diffusion path.

As shown in the figure, a conventional apparatus is constructed as follows.

As shown in FIG. 1 (a), a diffusion path in a conventional chemical vapor deposition apparatus performs a deposition process, and

A wafer loading section for carrying the wafer along the process path;

This equipment consists of the natural exhaust unit formed by the scavenger which naturally exhausts the surplus gas of the diffusion process unit.

In the diffusion process unit, a diffusion tube 11 forming a reaction chamber and a first gas inlet 12 for supplying nitrogen gas or a reaction gas to flow in a predetermined direction are formed in a part of the diffusion tube. The tube opposite the inlet has a structure that forms an opening that becomes the outlet when the wafer is loaded. In addition, a heating oil 13 for heating to a process temperature is formed around the tube.

The wafer loading unit blows inert gas onto the fork 18 that mounts the wafer 16 to the boat 17 and loads it into the diffusion process unit and the wafer loaded into the diffusion tube 11 to prevent contamination by external air. It consists of the 2nd gas inlet 15 to make.

As shown in (b) of FIG. 1, the natural exhaust port is formed around the passage 19 through which the wafer is loaded in the intermediate region of the diffusion process unit and the wafer loading unit to react with the wafer after the diffusion process to naturally retain the surplus gas remaining in the high temperature state. It is an apparatus comprised as the scavenger 14 to exhaust.

Referring to the CVD process by the conventional apparatus as follows.

After the wafer 16 to form the CVD film is sequentially stored in the boat 17 by using a chemical vapor deposition process, the boat is loaded on the fork 18 and loaded into the diffusion tube 11.

At this time, the inert gas atmosphere is formed by the nitrogen gas supplied from the first gas inlet 12 in the diffusion tube, and the upper portion of the fork is also inert gas atmosphere by the nitrogen gas supplied from the second gas inlet 15. To prevent the wafer from being contaminated from outside air.

In such a nitrogen gas atmosphere, the wafer loaded on the fork passes through the passage 19 in the center of the scavenger 14 at a moving speed of 3 cm / min and moves into the diffusion tube.

After the movement of the wafer into the tube is completed, the first gas inlet of the diffusion tube supplies the reaction gas, and the heating coil 13 formed around the tube is heated to a temperature necessary for the process.

After completion of the process in the diffusion tube, when nitrogen gas is supplied again from the first gas inlet, the wafer comes out of the tube in the reverse order to when it is loaded into the tube in the atmosphere of the inert gas.

However, in the case of performing the deposition process using the conventional CVD equipment as described above, vortices are formed due to the meeting of air at different temperatures in the passage where hot surplus gas in the diffusion tube meets the low temperature gas outside, and the inflow of external air accordingly. As a result, the wafer surface was exposed to external air and a native oxide film was grown on the wafer surface.

In order to solve the problems of the conventional apparatus, a rectangular nitrogen inlet tube is installed at the inlet of the diffusion furnace tube and a natural exhaust pipe is formed on the opposite side. The purpose is to provide a diffusion path to prevent this.

The present invention provides a diffusion tube 21 for forming a reaction chamber for performing a diffusion process, a first gas inlet 22 for supplying nitrogen or a reaction gas to the diffusion tube in a predetermined direction, and formed around the tube. A diffusion process unit composed of a heating oil 23 for heating the process temperature,

The fork 28 for loading the boat 27 mounted with the wafer 26 into the diffusion process section and the second gas introduction port 25 for forming an inert gas atmosphere on the wafer loaded into the diffusion tube are used to form the wafer. A wafer loading unit carrying along the loading path,

In the chemical vapor deposition apparatus formed as a scavenger which is formed around the passage in which the wafer is loaded in the intermediate region of the diffusion process portion and the wafer loading portion, and reacts with the wafer after the diffusion process to exhaust the remaining excess gas in the fine state.

The scavenger comprises a third gas introduction port 24-2 for supplying nitrogen gas, and a scavenger 24-1 for exhausting the gas from the third gas introduction port and excess gas from the diffusion process section. It is a natural oxide film diffusion diffusion path comprising an exhaust / blocking portion to block the outside air inflow.

2 is a diffusion path of the present invention.

As shown in Fig. 2A, the apparatus is constructed as follows.

The equipment of the present invention is to change the structure of the natural exhaust from the conventional equipment in the diffusion furnace in chemical vapor deposition equipment.

That is, the diffusion tube 21 forming the reaction chamber and the first gas inlet 22 for supplying the nitrogen gas or the reaction gas to flow in a predetermined direction are formed in a part of the diffusion tube, The opposite tube forms an opening that becomes an outlet when the wafer is loaded, and a diffusion process unit which includes a heating oil 23 for heating to a process temperature at the periphery of the tube to perform a deposition process;

A fork 28 for mounting the wafer 26 to the boat 27 to be loaded into the diffusion process section, and a second gas introduction port for blowing contamination with external air by blowing inert gas onto the wafer loaded into the diffusion tube. A wafer loading section for carrying the wafer along the loading path, consisting of 25, in the same manner as in the conventional apparatus,

The exhaust / blocking part which comprises the 3rd gas inlet 24-2 which supplies nitrogen gas, and the scavenger 24-1 which naturally exhausts the gas from the 3rd gas inlet, and the surplus gas of a diffusion process part. As a substitute for conventional natural exhaust.

The exhaust / blocking part of the present invention is formed in a rectangular shape so that the third gas inlet and the scavenger face each other in the upper and lower portions of the passage 29, which is the loading path of the wafer in the intermediate region of the diffusion process portion and the wafer loading portion, and then the wafer after the diffusion process. The excess gas in the high temperature state remaining after reacting with and the nitrogen gas supplied from the third gas inlet are naturally exhausted through the scavenger.

The third gas inlet is connected to the second gas inlet of the wafer loading portion and is supplied with nitrogen gas.

FIG. 2B is a detailed view of the exhaust / blocking part.

The third gas inlet 24-2 is located in the upper part of the passage, and the second gas inlet is connected through the connecting pipe 24-3, and a plurality of holes 24-4 are formed to introduce nitrogen gas into the passage. Supply.

A scavenger 24-1 that provides natural exhaust is located opposite the third gas introduction port of the exhaust / blocking part. A hole 24-5 is also formed in the scavenger to exhaust the gas in the passage.

Chemical vapor deposition process by the device of the present invention is as follows.

After the wafer 26 to form the CVD film is accommodated in the boat 27 using a chemical vapor deposition process, the boat is loaded on the fork 28 and loaded into the diffusion tube 21.

At this time, the atmosphere of the inert gas is formed by the nitrogen gas supplied from the first gas inlet 22 in the diffusion tube, and the second gas inlet 25 and the upper part of the passage 29 in the upper portion of the fork 28 are formed. The inert gas atmosphere is formed on the diffusion tube and the upper portion of the wafer by the nitrogen gas supplied from the third gas introduction port 24-2, thereby blocking external air inflow.

In such a nitrogen gas atmosphere, the wafer loaded on the fork is moved into the diffusion furnace tube at a moving speed of 3 cm / min.

After the movement of the wafer into the tube is completed, the first gas inlet 22 of the diffusion tube supplies the reaction gas instead of the nitrogen gas, and the heating coil 23 formed around the tube provides heat at a temperature necessary for the process. do.

After completion of the process in the diffusion tube, the first gas inlet is supplied with nitrogen gas again, and in such an inert gas atmosphere, the wafers come out of the tube in the reverse order as when loaded into the tube. do.

In the passage 29 of the inlet where the hot surplus gas in the tube and the external low temperature gas meet after the completion of the diffusion process, a vortex of branch gas is formed, and in the present invention, a third gas inlet is formed in the passage part where the vortex occurs. Nitrogen gas is supplied to prevent the inflow of external air by vortex.

Therefore, by using the device of the present invention it is possible to block the contact between the external natural air and the wafer to prevent the generation of a natural oxide film on the wafer to improve the quality of the oxide film.

Claims (2)

A diffusion tube 21 forming a reaction chamber for performing a diffusion process, a first gas inlet 22 for supplying nitrogen gas or a reaction gas in a predetermined direction to the diffusion tube, and a process temperature formed around the tube A diffusion process section composed of a heating oil (23) for heating in a furnace, The fork 28 for loading the boat 27 mounted with the wafer 26 into the diffusion process section and the second gas introduction port 25 for forming an inert gas atmosphere on the wafer loaded into the diffusion tube are used to form the wafer. A wafer loading unit carrying along the loading path, In the chemical vapor deposition apparatus formed as a scavenger which is formed around the passage in which the wafer is loaded in the intermediate region of the diffusion process portion and the wafer loading portion, and reacts with the wafer after the diffusion process to exhaust surplus gas remaining in the high temperature state. The scavenger comprises a third gas inlet 24-2 for supplying nitrogen gas, and a scavenger 24-1 for exhausting excess gas from the third gas inlet and the diffusion process section. Natural oxide film diffusion diffusion furnace characterized in that it comprises an exhaust / blocker to block the outside air inflow. The third gas inlet 24-2 is located at the upper part of the passage, and is connected to the second gas inlet through the connecting tube 24-3, and forms a plurality of holes 24-4 to form nitrogen in the passage. Supply gas, And a scavenger (24-1) for discharging the gas in the passage by forming a hole (24-5) opposite the third gas introduction opening around the passage.