一种新的抗总剂量辐射加固P沟道VDMOS终端结构

Using positive surface charge instead of traditional γ-ray total dose irradiation, the electric field distribution of a P-channel VDMOS terminal has been analyzed. A novel terminal structure for improving the total dose irradiation hardened of P-channel VDMOS has been proposed, and the structure is simulated and demonstrated with a -150 V P-channel VDMOS. The results show that the peak current density is reduced from 5.51 × 10^3 A/cm^2 to 2.01 × 10^3 A/cm^2, and the changed value of the breakdown voltage is 2.5 V at 500 krad（Si）. Especially, using 60Co and X-ray to validate the results, which strictly match with the simulated values, there is not any added mask or process to fabricate the novel structure, of which the process is compatible with common P-channel VDMOS processes. The novel terminal structure can be widely used in total irradiation hardened P-channel VDMOS design and fabrication, which holds a great potential application in the space irradiation environment.     

自动扶梯安全保护措施存在的遗留风险和附加风险

探讨了自动扶梯安全保护措施存在的遗留风险和附加风险,对这些风险产生的原因进行了分析,指出安全保护措施不能彻底消除风险,只能降低风险。为解决自动扶梯存在的遗留风险和附加风险,必须同时采取两种方式：在增加安全保护措施的同时尽量不出现新的较大的附加风险,并通过持续技术改进继续降低遗留风险。