Effects of contact metals on minority carrier diffusion lengths in GaAs
Effects of contact metals on minority carrier diffusion lengths in GaAs
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接触金属对 GaAs 中少数载流子扩散长度的影响
DOI：
10.1007/bf02655679
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发表时间：
1978
期刊：
影响因子：
--
通讯作者：
L. Vassamillet
中科院分区：
文献类型：
--
作者：
D. L. Partin;A. Milnes;L. Vassamillet
GaAs的接触技术包括优化接触电阻或肖特基势垒高度、合金循环条件、热老化、附着力和高分辨率加工的简易性等因素。少数载流子的性能可能会因接触金属的扩散而显著降低。在500℃、10s的典型合金化条件下，Ni在气相外延GaAs中扩散至少10μm，空穴扩散长度从4.4ym减少到1.7ym。在600°C时，Lp值为1.0μm。其他金属，如Fe、铂和铬，显著改善了Lpin VPE GaAs。当Fe在500℃下扩散5分钟时，Lp值从3.0Lp值增加到5.0Lp值。这些改善可能是由于Fe的扩散与复合中心的相互作用，如Ga空位复合体或Ni。虽然需要800-900℃的扩散，但Fe也会导致n型和p型铸锭中少数载流子扩散长度的增加，而且在这些温度下，Fe受主的掺杂会发生显著的变化。
Contact technology for GaAs involves optimizing such factors as contact resistance or Schottky barrier height, alloy cycle conditions, thermal ageing, adhesion, and ease of high resolution processing. Minority carrier properties may be significantly degraded by in-diffusing contact metals. At typical alloying conditions of 10 sec at 500° C, Ni diffuses at least 10 μm and reduces the hole diffusion length (Lp) in vapor phase epitaxial GaAs from 4.4 to 1.7 ym. At 600°C, Lpbecomes 1.0 μm. Other metals, such as Fe, Pt, and Cr, significantly improve Lpin VPE GaAs. Lpincreases from 3.0 to 5.0 μm for an Fe diffusion of 5 minutes at 500°C. These improvements may be due to interaction of in-diffused Fe with recombination centers, such as Ga vacancy complexes or Ni. Fe causes increases in minority carrier diffusion lengths also in n and p type ingot GaAs, though 800 – 900°C diffusions are required and at these temperatures the doping is significantly changed by Fe acceptors.