制备多孔硅的一种新方法

自从Canham观察到多孔硅(PS)的可见光致发光后,由于其可望成为可与Ⅲ—Ⅴ族半导体材料相媲美的新型光电子材料而引起了科学界极大的兴趣.目前,制备多孔硅一般都采用电化学腐蚀方法.

A NEW METHOD OF POROUS SILICON PREPARATION

The porous silicon (PS) was prepared by means of irradiation with He-Ne laser beam for the first time. Polished n-type(100) silicon wafers with resistivity 2-3Ω·cm were used as substrate. The silicon wafers were immersed in HF-H2O solution without current and irradiated with He-Ne laser beam. The position of PS formation is freely selected and the size of PS can be controlled by this technique.The surface morphology differs from that of anodized PS. It presents a distinct interference fringes. PL spectrum shape is similar to that of anodized PS. The samples excited by UV light or 488nm line from Ar ion laser at room temperature show intence red or orarge colour luminescence. It is found that the peak shifts to shorter wavelength and the PL intensity is obviously increased as the irradiating time is increased. Our experimental results show that this technique is not fit for p-type silicon wafers.