摘要
对注N^+形成的SOI材料,在不同条件下注入Si^+,分别使上层硅的表面、与埋层的界面及整个上层硅区域无定形化;再注入B^+:能量为25keV,剂量为1×10^(15)/cm^2,并在500—900℃的温度范围内退火30min。掠角背散射沟道测试表明:上层硅的表面或与埋层的界面区域被无定形化后,在后续热退火过程中分别存在由上层硅的内部向表面及由表面向内的固相外延过程;当上层硅被全部无定形化后,在500—600℃的温度范围内,上层硅由无定形相转变成多晶相,改变退火温度没有出现固相外延过程;扩展电阻测试发现:注入硼杂质在注N^+形成SOI材料上层硅中的激活率比其在单晶硅中的激活率低,利用Si^+注入使上层硅的表面或与理层的界面区域无定形化及在后续热退火过程中的固相外延再生长过程能提高注入硼杂质在注N^+形成SOI材料上层硅中的激活率。
Si+ was implanted into top silicon of SOI (silicon on insulator) material formed by N+ implantation to amorphize its surface, interface area between the top and the buried layer, and the whole top silicon. Then these SOI wafers and those without implantation were implanted by ET at 25 keV with dose of 1× 1015/cm2 and annealed in dry N2 ambient at different temperatures in the range of 500℃ to 900℃for 30 min. Glancing RBS/C measurement has shown that a solid phase epitaxial regrowth from the inner part of top silicon towards the surface or in the opposite direction exists respectively during post annealing if the surface or interface area of top silicon is amorphized. When the whole top silicon is amorphized, there is a phase transition from amorphous silicon to polysilicon for top silicon during post annealing in the temperature range from 500℃ to 600℃, and no solid phase epitaxial regrowth is found when the temperature is increased to 900℃. Spreading resistance probe measurements show that the activation rate of implanted boroh in the top silicon is lower than that in crystalline bulk silicon. The activation rate of implanted boron in the top silicon can be increased either by using Si+ implantation (to amorphize the surface or the interface area of top silicon) and the solid phase epitaxial regrowth.
出处
《核技术》
CAS
CSCD
北大核心
1992年第3期143-150,共8页
Nuclear Techniques
