硅N~+/NP连续反型外延生长过渡区的改善

<正>本文给出用外延工艺制备较窄的硅PN结补偿区的一种方法.这种工艺方法是在N型外延层生长结束后,预先通入P型掺杂剂硼烧一定时间,然后再进行P型层的生长,简称掺杂净化工艺.用该方法已能在同一炉中生长P层与N层,浓度与厚度均能较好地控制,制备的P-N补偿区最佳值在0.3μ以内.同时采用氯化氢(1030℃)低温腐蚀工艺,改善了N~+/N的过渡区,N~+/N过渡区≤0.2μ.工艺重复性较好.

An Improvement on the Transition Region of Si N~+/NP Layer by Continuous Conversion-Type Epitaxial Technology

This paper describes a new technique to prepare a narrower compensating region of silicon P-N junction by an epi-growth method. After finishing the growth of N-type epi-layer, and prepassing B2H8 as a P-type dopant into the reactor for a certain hour, the P-type epi-layer is grown, which we call as purifying of dopant. In this way, both P-type layer and N-type layer can be produced in the same run with controllable carrier concentration and thickness of the epi-layer. The optimum compensating region of P-N junction is within 0.3μm. On the other hand, by applying etching process with hydrogen chloride at lower temperature (1030℃), the N+/N transition region which is less than or equal to 0.2μm has been improved. This technique has achieved a better reproducibitity. The 8-mm silicon double drift impatt diodes made with our N+/NP epi-materials have shown good results.