Citation: |
Zhu Kuiying, Qian Qinsong, Zhu Jing, Sun Weifeng. Process optimization of a deep trench isolation structure for high voltage SOI devices[J]. Journal of Semiconductors, 2010, 31(12): 124009. doi: 10.1088/1674-4926/31/12/124009
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Zhu K Y, Qian Q S, Zhu J, Sun W F. Process optimization of a deep trench isolation structure for high voltage SOI devices[J]. J. Semicond., 2010, 31(12): 124009. doi: 10.1088/1674-4926/31/12/124009.
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Process optimization of a deep trench isolation structure for high voltage SOI devices
DOI: 10.1088/1674-4926/31/12/124009
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Abstract
The process reasons for weak point formation of the deep trench on SOI wafers have been analyzed in detail. An optimized trench process is also proposed. It is found that there are two main reasons: one is over-etching laterally of the silicon on the surface of the buried oxide caused by a fringe effect; and the other is the slow growth rate of the isolation oxide in the concave silicon corner of the trench bottom. In order to improve the isolation performance of the deep trench, two feasible ways for optimizing the trench process are proposed. The improved process thickens the isolation oxide and rounds sharp silicon corners at their weak points, increasing the applied voltage by 15–20 V at the same leakage current. The proposed new trench isolation process has been verified in the foundry's 0.5-μm HV SOI technology.-
Keywords:
- deep trench isolation,
- SOI,
- weak point,
- process optimization
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References
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Proportional views