氢气保护FZ硅掺镓研究

Gallium-doping of FZ-Si in a Hydrogen Atmosphere

掺镓硅(Si∶Ga)单晶是制作8～14μm波段红外焦平面阵列光电导探测器的优良材料,它可实现探测器阵列与信号处理电子线路的集成化。真空FZ硅掺镓试验表明,镓在区熔过程中一边发生分凝,一边向外蒸发。采用高纯氢气(略大于latm,纯度99.9999％)作保护气氛后镓的蒸发被抑制,硅中镶浓度已达1.8×10^(16)atom/cm^3,且纵向均匀性大为改善。新的掺镓方法避免了对超高纯硅棒可能引入的沾污,保证了单品质量。

Gallium-doped silicon(Si: Ga)crystals are an exallent material for infared focal plane photodetector arrays. By using this material the arrays can be integrated with related electronic circuits. Experiments on Ga-doped FZ-Si grown in vacuum demonstrated that Ga would segregate and evaporate during the Floating-zone process. In order to prevent Ga evaporation, a highly pure hydrogen atmosphere (at a pressure of a little greater than 1 atm, and with a purity of 99.9999％) is applied. As a result, the concentration of Ga in Si reaches 1.8x10^(10) atom/cm^3, and batter axial uniformity of Ga distribution is obtained. The new Ga-doping method radnces possible contaminations, and ensures the quality of Si crystals.