磁场中布里奇曼法生长碲镉汞晶体的缺陷腐蚀分析

ANALYSIS ON DEFECTS OF HgCdTe CRYSTAL GROWTH IN BRIDGMAN UNDER A MAGNETIC FIELD BY ETCHING METHOD

用化学腐蚀方法研究了磁场中布里奇更法生长碲镉汞晶体的位错和亚晶界，在施加磁场的样品中观察到分布较为均匀的位错和较少的亚晶界，这可能是由于在生长过程中施加了磁场对组分分凝和组分过冷起到了一定的抑制作用。

In this letter, it is discussed that the dislocations and subgrains of HgCdTe crystal grown from Bridgman method in magnetic field by chemical etching.The observed results are compared with samples without magnetic field. It provided exPerimental basis to study the mapnetic field's effect mechanisms on crystal growth and advanced crystal growth technology. Some results are obtained by using chemical etching method. Samples are prepared from ingots applied various magnetic field intensities including magnetic field during crystal growth.1. No apparent difference in average dislocation density.2. Samples without magnetic field contain rich substructure including subgrains and 3. dimensional dislocation net, while subgrain densities of samples from applied magnetic field during growth is clearly decreased and no 3-dimensional dislocation net is found.3. In the samples without magnetic field, the most subgrain's density exist in the center zone of the wafer, which exist in the off-center zone in the samples grown under magnetic field.Subgrains' off-center distribution means compositional off-center profiles which is an obvious characteristics of magnetic filed effect. Off-center profile can improve compositional uniformity and reduce subgrain density. Therefore, it is possible for application of the magnetic field to improve HgCdTe crystal quality and decrease its defects.