KR200177293Y1 - The shield for cvd - Google Patents

Abstract

The present invention relates to an improved structure of a shield for semiconductor chemical vapor deposition apparatus, in particular, in order to stabilize the deposition process conditions, the injector 10 having a reaction gas injection port 11 for injecting the reaction gas, and the reaction gas is A shield 20 having a nitrogen gas injection hole 22 for continuously injecting nitrogen gas from the outside of the reaction gas injection hole 11 so as not to produce byproducts by reacting in another region of the wafer W, and after reaction In the chemical vapor deposition apparatus including an exhaust pipe (30) for exhausting the gas to the outside, the nitrogen gas injection port 22 from the surface of the wafer (W) toward the outside toward the center of the reaction gas injection port (11) It is formed to maintain a predetermined nozzle inclination angle (T) to have a buffer region of a predetermined angle between the reaction gas and nitrogen gas, the degree of contamination of the shield screen 21 Under the condition that the flow rate of nitrogen gas is increased in order to reduce it, by changing the injection angle of nitrogen gas appropriately by a very simple structural improvement of the nitrogen gas injection port 22, the uniformity of the gas injection part N is suppressed and the product is suppressed. The quality of the shield can be improved, and the performance and efficiency of the device can be improved by stabilizing the deposition process conditions, and the contamination of the shield screen 21 is significantly lowered, thereby reducing the The present invention relates to a shield for semiconductor chemical vapor deposition apparatus which can extend the cleaning cycle for a considerable period.

Description

Shield for Semiconductor Chemical Vapor Deposition Equipment

The present invention relates to an improved structure of a shield for a semiconductor chemical vapor deposition apparatus. In particular, it is possible to reduce the uniformity defect of the gas injection unit to stabilize the deposition process conditions and to extend the shield cleaning cycle. The present invention relates to a shield for semiconductor chemical vapor deposition apparatus.

In general, a chemical vapor deposition apparatus (Chemical Vapor Depositor) is an injector (Injector) for injecting the reaction gas, such as SiH ₄ , B ₂ H ₆ , PH ₃ , O ₂ , N ₂ , as shown in Figure 1a to 2b (10), a shield (20) which continuously injects nitrogen gas to prevent the reaction gas from reacting in other areas of the wafer to produce a by-product, and exhausting the gas after the reaction to the outside. Exhaust 30 is configured for.

The shield 20 includes a shield screen 21 formed with a plurality of injection holes 22 for injecting nitrogen gas, and the injector 10 is positioned above the shield screen 21 to form the shield screen ( The reaction gas injection hole 11 is formed in the longitudinal direction through the center part of 21. As shown in FIG. In the figure, reference numeral 31 denotes an exhaust duct for guiding gas exhausted through the exhaust pipe 30 to the outside.

3 is an enlarged view of the gas injection unit N of the semiconductor chemical vapor deposition apparatus according to the prior art, and FIG. 4 is an injector 10 and a shield screen 21 for the conventional gas injection unit N. 5 illustrates a gas injection zone of FIG. 5 and FIG. 5 illustrates a shape in which nitrogen gas and a reaction gas flow through each other by a conventional gas injection unit N, and an injector shield is provided in the nitrogen gas injection port 22. Shield 22a and Vent Shield 22b are formed, respectively. Where W means wafer.

Referring to FIGS. 3 to 5, the gas flow process of the semiconductor chemical vapor deposition apparatus according to the prior art is as follows.

Through each reaction gas injection hole 11 of the injector 10, a hydride gas (Seydride gas), which is a mixture of SiH ₄ and B ₂ H ₆ , PH ₃ and the like is separated and injected nitrogen gas and oxygen gas at the same time, Nitrogen gas is continuously injected through the nitrogen gas injection port 22 and the injector shield 22a and the vent shield 22b of the shield 20, and the reaction gas is deposited on the surface of the wafer W and then It is discharged through the exhaust pipe 30 and the exhaust duct 31.

That is, as shown in the detailed view of FIG. 5, in the gas flow region, the hydride gas and the oxygen gas are divided by the separated nitrogen gas and weaken the flow state of the separated nitrogen gas, thereby reducing the surface of the wafer W. As a result, the hydride gas and the oxygen gas react to proceed with the deposition process.

However, in the conventional shield structure as described above, the uniformity of the gas injecting portion N is easily poor, and the maintenance of the device must be frequently performed, such as the shield 20 needs to be cleaned and replaced every 20 hours. There was this.

That is, the minute holes of the injector shield 22a and the vent shield 22b attached to the shield screen 21 are easily contaminated by the by-products of the reaction gas, so that the stream for continuous nitrogen gas is supplied from the shield 20. It will act as a barrier.

In addition, the conventional deposition apparatus is designed to advance two wafers (W) in one set, so that interference between each wafer (W) occurs, resulting in an increase in poor uniformity, and a contamination state of the shield 20. Even if the flow rate of nitrogen is increased to reduce the flow rate, the uniformity defect increases and the performance of the device itself decreases. In order to maintain the performance of the device, the moving speed of the wafer W should be about 6 inches per minute. In this case, too, there was a problem in that uniformity was increased.

Theoretically summarize the relationship between the flow rate change and the uniformity of nitrogen gas as described above.

When the total flow rate of nitrogen gas is 20 SLM, Q ₁ , and when 30 SLM is Q ₂ ,

Q ₁ = A × V ₁ ² ----- (1)

Q ₂ = A × V ₂ ² ----- (2)

However, A represents the total area of the nitrogen gas injection port 22, V ₁ represents the flow rate of nitrogen gas when Q ₁ , and V ₂ represents the flow rate of nitrogen gas when Q ₂ .

At this time, A is constant, so Q ₁ ∝ V ₁ ² , Q ₂ ∝ It was found that V ₂ ² increases the flow rate of nitrogen gas when the total flow rate of nitrogen gas increases. Therefore, when the flow rate of nitrogen is increased to reduce the contamination state of the shield 20, the shield 20 Since the flow rate of nitrogen gas injected from the gas is increased to affect the reaction atmosphere on the wafer W surface, the uniformity is increased.

As a result, there is a need for a method capable of reducing uniformity defects in a state where the flow rate of nitrogen gas is sufficiently maintained to suppress contamination of the shield 20.

Therefore, the present invention was devised to solve the above-mentioned problems. In order to stabilize the deposition process conditions by preventing the uniformity of the gas injection unit under the increased flow rate of nitrogen gas, the cleaning cycle of the shield is extended. It is an object of the present invention to provide a shield for semiconductor chemical vapor deposition apparatus that can be made.

Figure 1a is a front view showing the internal structure of a semiconductor chemical vapor deposition apparatus according to the prior art,

Figure 1b is a side view showing the internal structure of a semiconductor chemical vapor deposition apparatus according to the prior art,

Figure 1c is a bottom view showing the internal structure of a semiconductor chemical vapor deposition apparatus according to the prior art,

Figure 2a is a front view showing a partial cutaway appearance of the semiconductor chemical vapor deposition apparatus according to the prior art,

Figure 2b is a side view showing a partial cutaway appearance of the semiconductor chemical vapor deposition apparatus according to the prior art,

3 is an enlarged cross-sectional view of a gas injection unit of a semiconductor chemical vapor deposition apparatus according to the prior art;

4 is an explanatory diagram showing gas injection regions of an injector and a shield screen for a conventional gas injection unit, respectively;

FIG. 5 is a detailed view showing a shape in which nitrogen gas and a reaction gas flow through each other by a conventional gas injection unit; FIG.

FIG. 6 is an explanatory diagram showing gas injection regions of an injector and a shield screen, respectively, for a gas injection unit of a semiconductor chemical vapor deposition apparatus according to the present invention;

7 is a detailed view showing a shape in which nitrogen gas and the reaction gas flow by the gas injection unit according to the present invention,

8 is an exemplary view of another embodiment in which the nitrogen gas injection holes of the shield according to the present invention are formed in multiple shapes.

** Description of symbols for the main parts of the drawing **

N; Gas injection section T; Nozzle inclination angle

T1; Injection hole first inclination angle T2; Nozzle second inclination angle

W; Wafer 10; Injector

11; Reaction gas injection hole 20; shield

21; Shield screen 22; Nitrogen gas nozzle

22a; Injector shield 22b; Vent Shield

30; Exhaust pipe 31; Exhaust duct

The shield for semiconductor chemical vapor deposition apparatus according to the present invention for achieving the above object maintains a predetermined nozzle inclination angle from the wafer surface toward the outside toward the reaction gas injection port and the reaction gas and It is characterized in that it is formed to have a buffer region of a predetermined angle between the nitrogen gas.

In addition, the inclination angle of the injection hole is characterized in that it is configured to be included within the range of 0 ° to 90 °.

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

The basic structure of the semiconductor chemical vapor deposition apparatus according to the present invention is almost similar to the conventional structure shown in FIGS. 2A and 2B. That is, the injector 10 having a reaction gas injection port 11 for injecting a hydride, a reaction gas such as oxygen and nitrogen, and the reaction gas do not react in another region of the wafer W to generate a by-product. A configuration including a shield 20 having a nitrogen gas injection port 22 for continuously injecting nitrogen gas from the outside of the reaction gas injection port 11 and an exhaust pipe 30 for exhausting the gas after the reaction to the outside. Consists of

However, as shown in FIGS. 6 and 7, the shield 20 for semiconductor chemical vapor deposition apparatus according to the present invention has the nitrogen gas injection hole 22 toward the outside toward the reaction gas injection hole 11. It has a structural feature formed so as to maintain a predetermined nozzle inclination angle (T) from the surface of the wafer (W) to have a buffer region of a predetermined angle between the reaction gas and nitrogen gas. At this time, the injection hole inclination angle (T) is preferably configured to be included within the range of 0 ° to 90 °.

Referring to the gas flow state of the semiconductor chemical vapor deposition apparatus according to the present invention having such a configuration as follows.

Through each reaction gas injection hole 11 of the injector 10, a hydride gas (Seydride gas), which is a mixture of SiH ₄ and B ₂ H ₆ , PH ₃ and the like is separated and injected nitrogen gas and oxygen gas at the same time, Nitrogen gas is continuously injected through the nitrogen gas injection port 22 of the shield 20 while maintaining a predetermined injection port inclination angle T, and is injected through the nitrogen gas injection port 22 on the surface of the wafer W. Since a buffer region is formed between the nitrogen gas and the reaction gas so that mutual interference does not occur, the reaction gas performs a uniform deposition reaction process on the surface of the wafer W, and then the exhaust pipe 30 and the exhaust duct 31 are removed. Can be discharged through.

That is, as shown in the detailed view of FIG. 7, in the region where the reaction gas flows, the hydride gas and the oxygen gas are separated by the separated nitrogen gas, and the flow state of the separated nitrogen gas is weakened, thereby decreasing the flow of the wafer (W). When the hydride gas and oxygen gas react to reach the surface of the deposition process, the deposition process proceeds, and the nitrogen gas injected through the injection port 22 of the shield 20 reaches the wafer W. A predetermined inclination angle corresponding to the injection hole inclination angle T is formed with a predetermined gap (buffer area) from the gas, and proceeds from the outside of the reaction gas injection hole 11 toward the surface of the wafer W, thereby interfering with the nitrogen gas and the reaction gas. In addition to this, the by-products of the reaction gas are suppressed from occurring in the rest of the region other than the flow region on the wafer W surface. From being created and to create a reaction atmosphere, eventually deposited uniformity is significantly improved with the stabilization of the deposition process conditions.

In the above embodiment, the larger the injection hole inclination angle T, the wider the buffer region, and thus the deposition reaction atmosphere and uniformity may be improved.

On the other hand, Figure 8 briefly shows another embodiment of the structure of the shield 20 of the present invention, the nitrogen gas injection port 22 is centered toward the reaction gas injection port 11 toward the outside toward the wafer (W) A predetermined nozzle inclination angle T that varies from the surface to a polygonal angle, that is, a nozzle first inclination angle T1 and a nozzle inclination second inclination T2 is arbitrarily formed to provide a plurality of buffer regions having a predetermined angle between the reaction gas and nitrogen gas. It may be configured to be provided with a dog. At this time, it is preferable to limit the first inclination angle T1 of the injection hole, the second inclination angle T2 of the injection hole, and any other inclination angle of the injection hole, which may be arbitrarily formed, to a polygonal shape of 10 times or less, and the deposition reaction state is Since the same as in the basic embodiment of the present invention will be omitted detailed description.

Effects of the present invention that can be expected by the configuration and action as described above are as follows.

The shield for semiconductor chemical vapor deposition apparatus according to the present invention is a nitrogen gas by a very simple structural improvement of the nitrogen gas injection port 22 under the condition that the flow rate of nitrogen gas is increased to reduce the pollution degree of the shield screen 21. By appropriately changing the blind spots, the uniformity of the gas injection unit N can be suppressed to improve the quality of the product, and the performance and efficiency of the apparatus can be improved by stabilizing the deposition process conditions. Since the contamination degree of the shield screen 21 and the like is significantly lowered, there is an advantage that the cleaning cycle of the shield 20 can be extended for a considerable period of time.

Claims (4)

An injector having a reaction gas injection hole for injecting a reaction gas, and a nitrogen gas injection hole for continuously injecting nitrogen gas from the outside of the reaction gas injection hole to prevent the reaction gas from reacting in another area of the wafer to produce a by-product. In a chemical vapor deposition apparatus comprising a shield having, and an exhaust pipe for exhausting the gas after the reaction, the nitrogen gas injection port maintains a predetermined nozzle inclination angle from the wafer surface toward the outside toward the center of the reaction gas injection port And a buffer zone at a predetermined angle between the reaction gas and nitrogen gas. The shield for semiconductor chemical vapor deposition apparatus according to claim 1, wherein the injection hole inclination angle is included in a range of 0 ° to 90 °. The method of claim 1, wherein the nitrogen gas injection hole maintains a predetermined inclination angle of the injection hole that varies from the wafer surface toward the outside with respect to the reaction gas injection hole, so that a plurality of buffer regions having a predetermined angle between the reaction gas and the nitrogen gas. Shield for semiconductor chemical vapor deposition apparatus, characterized in that formed to be provided. The shield for semiconductor chemical vapor deposition apparatus according to claim 3, wherein the nozzle inclination angle is limited to a polygonal shape of up to 10 times.