在p型硅MOS结构Si/SiO_2界面区中与金有关的界面态和深能级

INTERFACE STATES AND DEEP CENTERS IN Au-DOPED MOS STRUCTURES

用深能级瞬态谱(DLTS)技术详细研究了金在p型<111>晶向硅MOS结构Si/SiO_2界面区中的行为。结果表明,金与Si/SiO_2界面缺陷H_(it)(0.494)相互作用形成新的缺陷Au-H_(it)(0.445),和金在硅的禁带中产生一个能量分布很广的连续界面态,利用这些界面态可以合理地解释金使硅MOS结构平带电压向正方向移动的物理机制。结果还表明,在Si/SiO_2界面附近的半导体中,金施主中心的剖面分布不是单调地向界面增加,而是在距界面0.37μm处有一个最大值。

Behavior of gold in the Si/SiO2 interface region has been investigated using deep level transient spectroscopy (DLTS) in the MOS structures made on p-type silicon wafers with <111> orientation. The results are as follows. A new defect, Au-H_it(0.445), has been observed at the interface, which is the incorporation of gold atom by the interaction with the interface defect, H_it(0.494). A continuous spectrum of the interface states related to gold has also been measured in the lower half of Si band gap, which are acceptors, and the physical mechanism of the positive shift of the flat band voltage of the MOS structure caused by gold doping ean be explained in terms of these gap states. The profile of the gold donors in the silicon near the interface has been obtained, which is not monotonically increase towards the surface but exhibits a maximum at 0. 37μm from the surface.