退火工艺对可控硅辐照效应的影响

Influence of Annealing Process on Irradiation Effect of Silicon Controlled Rectifier

应用1.4 Me V电子束对单向可控硅晶圆芯片进行固定注量率辐照,通过触发电流和少子寿命表征辐照效应,研究了退火工艺对辐照效应的影响。结果表明:电子辐照缩短单向可控硅少子寿命,增大触发电流。经350℃退火后触发电流恢复到辐照前水平,少子寿命虽有一定恢复,但远比辐照前短。在试验的注量范围内k系数为常数,退火后k系数与注量相关,小注量时较小。常温存放对辐照效应有较大影响,长时间存放不利于200℃退火而有利于300℃退火。

The annealing process of silicon controlled rectifier（SCR） after irradiation were studied. SCR wafer was irradiated by 1. 4 Me V electronic beam with fixed fluence rates. Then the triggering current and minority carrier lifetime of SCR were measured. The experimental results show that the value of minority carrier lifetime is decrease and the value of triggering current is increase after irradiation. After annealing at 350 ℃,the triggering current of SCR was recovered to the level before irradiation. The minority carrier lifetime was recovered,but the value was far lower than that before irradiation. In irradiation fluence range of the experiment,the k was constant. After annealing process,the k coefficient was related to irradiation fluence. Under low irradiation fluence, the k coefficient was small. Storage at room temperature brought large influence on the irradiation effect of SCR. Long time storage had favorable influence on the annealing effect at 300 ℃,and unfavorable influence on the annealing effect at 200 ℃.