摘要
利用超高真空化学气相淀积 (UHV/ CVD)设备 ,在掺 As n+ 型 Si衬底上生长了掺 P n- 型 Si外延层 .用扩展电阻法分析了在不同的生长温度和 PH3气体流量下生长的 Si外延层的过渡区厚度 .结果表明 ,生长温度对 n+ - Si衬底的 As外扩有明显影响 ,在 70 0℃下生长的 Si外延层的过渡区厚度为 0 .16 μm,而在 5 0 0℃下仅为 0 .0 6 μm,且杂质分布非常陡峭 .X射线双晶衍射分析表明在 70 0℃下生长的 Si外延层的质量很高 .制作的锗硅异质结晶体管(Si Ge HBT)的击穿特性很硬 ,击穿电压为 14 .5 V,在 VCB=14 .0 V下的漏电流仅为 0 .3μA;输出特性很好 ,在 VCE=5 V,IC=3m A时的放大倍数为 6
n--type silicon epitaxial layers were grown on arsenic-doped n+-type silicon substrate by ultra-high vacuum chemical vapor deposition(UHV/CVD).The transition region thicknesses of the Si layers grown under different PH 3 flux and different growth temperatures were investigated by spread-resistance probe.Results show that the growth temperature has remarkable influence on the arsenic diffusion from the Si substrate.The thickness of the transition region was 0.16μm grown at 700℃ and 0.06μm at 500℃,respectively.Moreover,the dopant profiles were very abrupt.X-ray diffraction investigation of the Si layer grown at 700℃ shows the quality of Si layer is very high.Silicon-germanium hetero-junction bipolar transistor (SiGe HBT) was fabricated by a revised double-mesa polysilicon-emitter process.Tests show that the CB-junction breakdown characteristic of the SiGe HBT is very hard,and the leakage current is only 0.3μA at V CB=14.0V.The SiGe HBT device also had good output performance with current gain β=60 at V CE=5V and I C=3mA.
基金
国家高技术研究发展计划资助项目 (批准号 :2 0 0 2 AA3 Z12 3 0 )~~
