CN-224218787-U - Wet etching equipment for wafer and feeding system thereof

Abstract

The utility model provides wet etching equipment for a wafer and a feeding system thereof, wherein the feeding system comprises a mixing device and a liquid silicon dioxide supply part; the mixing device comprises a mixed liquid storage part and a circulating mechanism, wherein the mixed liquid storage part is connected with the liquid silicon dioxide supply part, the circulating mechanism comprises a circulating pipeline and a first pump, two ends of the circulating pipeline are respectively communicated with the mixed liquid storage part, and the first pump is arranged on the circulating pipeline. The mixed solution storage part is used for containing the phosphoric acid solution and also receiving the liquid silicon dioxide from the liquid silicon dioxide supply part, and uniformly mixing the liquid silicon dioxide and the phosphoric acid solution through the first pump action to form a uniform silicon dioxide-phosphoric acid solution. The feeding system is applied to wet etching equipment for wafers, so that acid changing operation is carried out on the wet etching equipment, and the change of the etching rate and the selection ratio of SIN/SiO2 caused by the great reduction of the concentration of silicon ions in an etching groove due to acid changing can be avoided.

Inventors

• ZENG CANCAN
• CHI GUOWEI

Assignees

• 重庆芯联微电子有限公司

Dates

Publication Date

20260508

Application Date

20250520

Claims (10)

1. 1. The feeding system for the wet etching equipment of the wafer is characterized by comprising a mixing device and a liquid silicon dioxide supply part, wherein: The mixing device comprises a mixed liquid storage part and a circulating mechanism, wherein the mixed liquid storage part is connected with the liquid silicon dioxide supply part, the circulating mechanism comprises a circulating pipeline and a first pump, two ends of the circulating pipeline are respectively communicated with the mixed liquid storage part, and the first pump is arranged on the circulating pipeline.
2. 2. The feed system for a wet etching apparatus for a wafer according to claim 1, wherein the mixing device further comprises a silicon ion concentration detecting element provided on the mixed liquid storage section.
3. 3. A feed system for a wet etching apparatus for wafers as set forth in claim 1 wherein the mixing device further comprises a filter element disposed on the circulation line.
4. 4. The feed system for a wet etching apparatus for a wafer according to claim 1, wherein the mixing device further comprises a heater and a temperature detecting element, which are sequentially provided on the circulation line.
5. 5. The feed system for a wet etching apparatus for a wafer as set forth in claim 1 wherein the liquid silica supply section includes a liquid silica tank, a first feed line, and a first valve, the liquid silica tank being connected to the mixed liquid storage section through the first feed line, the first valve being disposed on the first feed line.
6. 6. The feed system for a wet etching apparatus for a wafer as recited in claim 5, wherein the liquid silicon dioxide supply further comprises a second pump, the second pump being disposed on the first feed line.
7. 7. The feeding system of claim 6, wherein the number of liquid silica tanks is two, the first feeding pipeline comprises a main pipeline and two branch pipelines, one end of the main pipeline is connected with the mixed liquid storage part, the other end of the main pipeline is respectively connected with the two branch pipelines, each branch pipeline is connected with one liquid silica tank, each branch pipeline is provided with one first valve, and the second pump is arranged on the main pipeline.
8. 8. The supply system for a wet etching apparatus for wafers according to claim 1, wherein the mixed liquor storage section is further connected to a phosphoric acid supply section through a second supply line, and the second supply line is provided with a second valve.
9. 9. The supply system for a wet etching apparatus for wafers according to claim 1, wherein the mixed solution storage part is further connected to the deionized water supply part through a third supply line, and the third supply line is provided with a third valve.
10. 10. Wet etching apparatus for wafers, characterized by comprising an etching tank assembly, a fourth supply line, a fourth valve and a supply system for a wet etching apparatus for wafers according to any one of claims 1 to 9, the etching tank assembly being connected with the mixed liquor storage section through the fourth supply line, the fourth supply line being provided with the fourth valve.

Description

Wet etching equipment for wafer and feeding system thereof Technical Field The utility model belongs to the technical field of semiconductor production equipment, and particularly relates to wet etching equipment for wafers and a feeding system thereof. Background In the wet etching process of a semiconductor wafer, the etching rates of nitride and silicon dioxide need to be controlled simultaneously, and the etching rates of the nitride and the silicon dioxide must meet a certain selection ratio. When phosphoric acid is used as an etching agent for etching the wafer, as the amount of the etched groove is increased, the concentration of silicon dioxide (or silicon hydroxide) in the etched groove is continuously increased, and the silicon dioxide (or silicon hydroxide) is covered on the surface of the wafer to be etched after exceeding a threshold value, so that the etching rate of SIN/SiO 2 is reduced, and the selectivity ratio fluctuates. Therefore, the concentration of silicon ions in the etching tank needs to be controlled during the execution of the etching process. In actual work, when the running amount in the etching tank reaches a certain value, the etchant in the etching tank needs to be replaced, namely the acid replacing operation is executed. At present, the acid changing operation commonly adopted in the industry is to discharge at least a part of etching liquid in the etching tank, and normal-temperature phosphoric acid is supplemented to the etching tank by a factory or a phosphoric acid storage tank. The acid-changing operation causes the concentration of silicon ions in the etching tank to be greatly reduced after the acid is changed, so that the etching rate and the selection ratio of SIN/SiO2 are changed. Disclosure of utility model The utility model aims to provide wet etching equipment for wafers and a feeding system thereof, which aim to keep the concentration of silicon ions in materials supplied to an etching tank in a proper range and avoid the change of the etching rate and the selection ratio of SIN/SiO2 caused by the larger change of the concentration of the silicon ions in the etching tank due to the replacement of an etchant. In order to achieve the above object, the present utility model provides a feeding system for a wet etching apparatus for wafers, comprising a mixing device and a liquid silicon dioxide supply part, wherein: The mixing device comprises a mixed liquid storage part and a circulating mechanism, wherein the mixed liquid storage part is connected with the liquid silicon dioxide supply part, the circulating mechanism comprises a circulating pipeline and a first pump, two ends of the circulating pipeline are respectively communicated with the mixed liquid storage part, and the first pump is arranged on the circulating pipeline. Optionally, the mixing device further includes a silicon ion concentration detection element provided on the mixed liquid storage section. Optionally, the mixing device further comprises a filter element, the filter element being disposed on the circulation line. Optionally, the mixing device further comprises a heater and a temperature detection element, and the heater and the temperature detection element are sequentially arranged on the circulation pipeline. Optionally, the liquid silica supply part comprises a liquid silica storage tank, a first supply pipeline and a first valve, wherein the liquid silica storage tank is connected with the mixed liquid storage part through the first supply pipeline, and the first valve is arranged on the first supply pipeline. Optionally, the liquid silica supply further comprises a second pump, the second pump being disposed on the first feed line. The first supply pipeline comprises a main pipeline and two branch pipelines, one end of the main pipeline is connected with the mixed liquid storage part, the other end of the main pipeline is respectively connected with the two branch pipelines, each branch pipeline is connected with one liquid silicon dioxide storage tank, each branch pipeline is provided with one first valve, and the second pump is arranged on the main pipeline. Optionally, the mixed liquor storage part is further connected with the phosphoric acid supply part through a second supply pipeline, and the second supply pipeline is provided with a second valve. Optionally, the mixed liquor storage part is further connected with the deionized water supply part through a third supply pipeline, and a third valve is arranged on the third supply pipeline. In order to achieve the above object, the present utility model further provides a wet etching apparatus for a wafer, including an etching tank assembly, a fourth supply line, a fourth valve, and a supply system of the wet etching apparatus for a wafer as set forth in any one of the preceding claims, wherein the etching tank assembly is connected to the mixed solution storage part through the fourth supply line, and the fourth supply line is pro