研究了碲镉汞富碲垂直液相外延技术.在研究该关键技术的过程中, 提出了一种方法以检查外延前(Hg1-x Cd x ) 1-y Te y 母液的均匀性.并且, 通过减小生长腔体中的自由空间, 对气体的对流和汞回流进行了抑制, 及通过改进 工艺过程中的温度控制方式来应对因对流和汞回流而造成的生长温度不确定性.在解决上述关键技术后, 实现了 碲镉汞垂直液相外延工艺的稳定性, 所外延的中波碲镉汞材料的组分可重复性做到了 ±0.005, 厚度控制能力达到 了±5μm , 40×30mm 2 外延材料的横向组分均匀性(相对均方差)小于1.3×10 -3 , 同生长批次材料片与片之间的组 分和厚度差异分别小于0.001和1μm.在10mm线度上, 表面起伏小于1μm.经热处理后, 中波汞空位p型材料在 77K下具有较高的空穴迁移率.另外, 和水平推舟技术相比, 垂直碲镉汞液相外延在提供大批量和大面积相同性能 材料方面具有明显的优势, 这对于二代碲镉汞红外焦平面批生产技术和拼接型超大规模红外焦平面技术的发展都 具有重要的意义.

Te-rich dipping technique of HgCdTe liquid phase epitaxy (LPE) was studied. An experimental method was proposed to check the homogenization of (Hg 1-x Cd x ) 1-y Te y melt just before the dipping. The gas convection and Hg cir- cumfluence in the growth chamber were suppressed by reducing the free space of gowth chamber. The process control of the growth temperature was improved to suit for the poor temperature reproducibility induced by the gas convection and Hg cir- cumfluence. In this way, the composition reproducibility of MW HgCdTe grown by LPE reaches ±0.005. The thickness uncertainty is controlled to be within ±5μm and the transverse composition uniformity (standard square deviation/average) for 40×30mm 2 wafer is less than 1.3×10 -3 . The differences of the composition and thickness are less than 0.001 and 1μm, respectively, for the different wafers grown at the same time. The surface fluctuation of the sample is less than 1μm for over 10 mm dimension. It was also observed that, after thermal treatment, our p-type MW HgCdTe epilayers with Hg- vacancy doping have higher hole mobility at 77K compared with the materials grown by other techniques. Besides, com- pared with horizontal slide LPE, the dipping technique has obvious advantage in the manufacture of large size HgCdTe films and multi-wafers with the same property. Hence, the technique is helpful to develope the batch manufacturing technology of the second generation HgCdTe infrared focal plane array, and it is also significant to develope the splicing of super-large- scale infrared focal plane arrays.