Abstract
In this thesis, the object is to use aminosilane transferred on amorphous silicon as a hard mask to fabricate amorphous silicon nanowires by nano-contact printing technique and apply nickel induced lateral crystallization technique to fabricate poly Si nanowires. Firstly, the ink prepared by mixing aminosilane with methanol at volume ratio is 1 : 17, was spin coated on silicon wafer. The ink aminosilane was then transferred on the HSQ molds with line width = 80, 100, 150, and 200 nm and width/space ratio 0.1 and 1. To promote adhesion of aminosilane and substrates, O2 plasma treatment was applied on substrates. The nano-contact printing technique was developed to transfer aminosilane from HSQ mold to dry oxide and amorphous Si film with printing pressure is 15-60 psi and temperature is 100 oC for 30 s. Then the transferred aminosilane pattern was used as a hard mask to define amorphous Si nanowires by dry etching process. Secondly, the Ni with thickness is 2-8 nm was evaporated on amorphous Si film and Si nanowires. The samples were annealed at 550 oC for 1.5-12 hr, subsequently. In order to distinguish amorphous-Si and poly Si formed by metal induced lateral growth, the etching solution HF/H2O/HNO3/CH3COOH at volume ratio 1/9/50/50-1/9/5/50 was to wet etch the samples for 3-7 s. The above transferred aminosilane, Si nanowries and morphology of poly Si were examined by SEM and AFM.