瞬态电压抑制器的减压外延工艺研究

瞬态电压抑制器是用于保护高频电路电压瞬变和浪涌防护的半导体器件,由低击穿电压的雪崩二极管和低电容二极管组成。低电容二极管需要在高掺杂的P型衬底上生长近似本征的超高电阻率的N型外延层。该工艺面临的难点在于如何减少P型自掺杂并稳定控制外延层的电阻率。文章利用扩展电阻测试方法重点研究了8英寸化学气相外延减压工艺中工艺参数对外延层质量的影响和对图形畸变的影响。

Study on the RP Epitaxial Process of TVS Diode

Transient Voltage Suppressor（TVS） is a semiconductor device used to protect high frequency circuits from electrostatic discharge, voltage fast transient, and surge. It consists of low breakdown voltage avalanche diode and low capacity diode. The low capacity diode is required to grow N-type epitaxial layer with ultra-high resistivity or intrinsic layer on heavily doped P-type substrate. It is a big challenge to suppress self-doping from P-type substrate and get high resistivity N-EPI layer with controlled resistivity. In this paper, the key parameters which impact EPI process are studied using SRP method and the effect on pattern distortion is also presented.