单晶硅表面贵金属晶粒层的制备

将预处理过的单晶硅p-Si(100)浸入含贵金属盐的HF溶液, 制备了Ag, Au, Pd和Pt的晶粒层. 用原子力显微镜(AFM)、开路电位(OCP)、循环伏安(CV)和交流阻抗(A. C. Impedance)方法对晶粒层性能进行了考察. 形貌显示, 在浸镀20 s后, Ag和Pd晶粒层基本上覆盖了硅基底, Ag颗粒致密, Pd颗粒之间仍有空隙且晶粒较Ag大. Au晶粒层部分覆盖了基底, 而Pt只有极少数的晶粒. 60 s后, Ag, Pd和Au晶粒层都完全覆盖了基底, 而Pt晶粒仍然较少, 但晶粒有所长大. 循环伏安显示, Pd的溶出峰电流比Ag, Au, Pt高1个数量级. 交流阻抗测量表明, Pd晶粒层阻抗最小. 结果表明, Ag, Pd和Au都能用浸入沉积的方法在单晶硅上短时间内制备出晶粒层, 而Pt不能, 选用哪种晶粒层, 需要根据后续工序和实际需要而定.

Preparation of Noble Metal Seed Layers on Monocrystal Silicon

Ag, Au, Pd, and Pt seed layers were prepared by immersion deposition onto p-Si(100) wafers from noble metal-salt solution containing HF. Atomic force microscopy (AFM), open circuit potential with time (OCP), cyclic voltammetry (CV) and A.C. impedance were used to characterize the seed layers. AFM showed that during 20 s immersion deposition, the substrate was covered completely by the Ag and Pd seed layers; for Au, about 37% of the substrate was covered, while for Pt, the seed layer was very sparse and almost could not be detected. When the immersion time was prolonged to 60 s, the substrates were covered completely by Ag, Pd and Au seed layers, but the particle density of Pt had no obvious improvement. In cyclic voltammograms of the noble metal seed layers, the oxidation current of Pd was one order of magnitude bigger than those of others. A.C. impedance revealed that the impedance of Pd was the lowest. Results indicated that Ag, Pd and Au seed layers could be prepared on p-Si by short-time immersion deposition.