论文部分内容阅读
我们用红外透射光谱和X射线双晶衍射等，研究了退火对CdZnTe晶体质量的影响．结果表明，在Cd气氛中，700℃，退火5小时以上，能大量地去除晶片中的Te沉淀，提高其红外透射比；同时，退火也导致了晶片表面的损伤，损伤层为50～130μm．表面结构损伤的原因是，（1）Cd气氛中退火，CdZnTe晶体表面的Zn损失；（2）退火过程中，吸附在沉淀物周围的杂质，尤其是快扩散杂质，将随着沉淀相的消失而迁移到晶体的表面，从而破坏了表面的晶体结构．退火后，磨去损伤层，可将聚集在表面的这些杂质除去，更有利于外延生长或器件制备．
We studied the effect of annealing on the quality of CdZnTe crystals by infrared transmission spectroscopy and X-ray double crystal diffraction. The results show that annealing at 700 ℃ for more than 5 hours in Cd atmosphere can largely remove the Te precipitation in the wafer and increase the infrared transmittance. Simultaneously, annealing also results in the damage of the wafer surface with damage layer of 50 ~ 130μm. The reason of surface structure damage is that: (1) annealing in Cd atmosphere and loss of Zn on the surface of CdZnTe crystal; (2) during annealing, impurities adsorbed around the precipitate, especially fast diffusion impurities, will disappear as precipitation phase disappears While migrating to the surface of the crystal, thus undermining the crystal structure of the surface. After annealing, abrading the damaged layer can remove these impurities accumulated on the surface, which is more conducive to epitaxial growth or device preparation.