GaAs/AlAs超晶格室温下的输运机制及自维持场畴振荡  

Room Temperature GaAs/AlAs SL Vertical Transport and Self Sustained Field Domain Oscillation

作　　者：武建青[1] 江德生[1] 孙宝权[1] 

机构地区：[1]中国科学院半导体研究所

出　　处：《Journal of Semiconductors》1998年第10期788-792,共5页半导体学报（英文版）

摘　　要：在ＧａＡｓ／ＡｌＡｓ（１０ｎｍ／２ｎｍ）弱耦合掺杂超晶格Ｉ－Ｖ曲线的第一个平台上，我们首先观测到了直流偏压下的室温微波振荡．观测到的最高振荡频率可达１４２ＭＨｚ．这种由级联隧穿引起的振荡在测试温度范围１４～３００Ｋ内始终存在．经分析发现：由于垒层仅有２ｎｍ，电子隧穿通过垒层的几率很高，相比之下，电子越过势垒而产生的热离子发射电流要小得多．在温度低于３００Ｋ时，超晶格内的纵向输运机制是级联共振隧穿和声子辅助隧穿．这是室温仍然能观测到自维持振荡的主要原因．由于实现振荡所施加的偏压比较低（在室温下偏压范围大约为０．５～２Ｖ），有利于抑制室温下通过Ｘ谷的热离子发射电流．Abstract The temperature dependence of currents of the SL diode at six biases are measured and used to analyse the vertical transport mechanism in AlAs/GaAs SL. The room temperature microwave (MW) oscillations are observed in GaAs/AlAs (10nm/2nm) doped weakly coupled superlattices (SLs) in the first plateau of the I V curve. The sequential tunneling induced oscillations are detected in the temperature range from 15K to 300K by applying DC bias on SL. It is found that up to 300K the dominant transport mechanisms in the SL diode are sequential resonance tunneling and phonon assisted tunneling. The low bias voltage condition under which the oscillations are realized is helpful to restrain thermal ionic emission through X valley in the room temperature transport.

关 键 词：砷化镓 砷化铝 超晶格 场畴振荡 

分 类 号：TN304.23[电子电信—物理电子学]