Oxide Etch in Shallow Trench Isolation
碩士 === 國立交通大學 === 工學院碩士在職專班半導體材料與製程設備學 === 94 === Due to photo resist is widely used in pattern definition with semiconductor process, we need photo resist to protect active region when silicon dioxide inside the shallow trench isolation etch .The thesis studies the high selectivity in oxide over ni...
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| Format: | Others |
| Language: | zh-TW |
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2006
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| Online Access: | http://ndltd.ncl.edu.tw/handle/55852764983108910898 |
| Summary: | 碩士 === 國立交通大學 === 工學院碩士在職專班半導體材料與製程設備學 === 94 === Due to photo resist is widely used in pattern definition with semiconductor process, we need photo resist to protect active region when silicon dioxide inside the shallow trench isolation etch .The thesis studies the high selectivity in oxide over nitride with different process parameters split. The hard mask layer will use silicon nitride instead of resist material. The concept of mask less will diminish process flow and production cost.
To increase the etch selectivity for silicon dioxide inside shallow trench isolation to silicon nitride in active region, the parameters of etch will be properly used and adjusted in the experiment. The key factors are process gas ratio and pressure. To fine tune the gas ratio of CHF3 to CF4 with low pressure condition, it will get the highest etch selectivity when the gas ratio value is 4.The monitor wafers will be used to check remain nitride and oxide loss. From the SEM image, we find the silicon nitride in active region will over 9.2nm and silicon dioxide loss in shallow trench isolation is near 180 nm. No mask used in the experiment is available.
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