【摘要】 对压敏器件用低阻NTD CZ Si(直拉硅)的深辐照工艺进行了研究,主要包括三个方面内容:(1)配合自然单晶生长工艺的改进,对CZ与FZ单晶痕量重金属杂质进行中子活化分析。(2)在同样深辐照条件下对CZ与FZ单晶的β-低本底剩余放射性进行跟踪测量,所得到的放射性强度衰减曲线表明CZ与FZ是一致的,同样可以采用NTD技术。(3)低阻CZ硅单晶中子嬗变掺杂工艺研究,根据目标电阻率,适当地选择电子移率μ_c值,通过实验与校正,得到合理的掺杂系数K值。保证掺杂精度,使晶体掺杂的命中率获得显著提高,与常规掺杂相比由原来的40％提高到90％左右。径向不均匀性Δρ≤5％,径向微区不均匀性Δρ≤3～5％。首批量低阻CZ NTD硅的研制及其压敏器件生产中的应用,获得良好的效果,压敏器件性能达到规定标准,并明显地优于普通CZ硅材料的产品,成品率和优品率由40％提高到60％。更多还原

【Abstract】 A study of pressure sensing elements which are made of low-resistivity CZ silicon crystal (8~12Qcm) with deep-irradiation has been completed. The main contents are as follows, (l) The trace heavy metal impurities in the new CZ and FZ Si are measured by the neutron activation analyzing method to look into the improved growth technique of natural single crystal. (2) Under the same condition of deep-irradiation,the CZ,FZ Si beta radioactivity decay curves which were obtained by the track measurement with a low-backgrouod beta device are same. This means that the CZ Si can be doped with NTD process just as same as the FZ Si. (3) The process study of NTD for low-resistivity CZ Si has been completed if the value of electron mobility is properly selected in accordance with the target resistivity and the value of doping coefficient K is dertermined by experiments, the doping accuracy can be ensured and remarkably raised. Comparing with the normal doping method, the doping hitting accuracy is incresed from 40% to 90%?the radial nonuniformity Ap is less then 5% and the radical microarea nonuniformity Apm is less then 3-5%. The first batch of irradiated products of low-resistvity NTD CZ Si has been used for the pressure sensing elements. The results are satisfied and the performance of pressure sensing elements has reached to the prescribed standard. The rate of qualitied and high quality products has been increased from 40% to 60%.It is obvious that the NTD CZ Si is much better than the ordinary CZ Si.更多还原