Nano-pattern Formation Using Liquid Silicon
In this chapter, direct patterning methods for device fabrication are introduced. The first one, described in 8.1, is a method for the area-selective deposition of polysilane patterns in silicon solution, which is based on the principle of Type 4 conversion in Case 2 shown in Fig. 1.1 in Chap. 1. Two kinds of selectivity mechanisms are utilized: one is the difference of molecular forces and the other is a reactive difference. The second method, described in 8.2, is a direct drawing of Si lines using CPS vapor and an electron or ion beam. This is a kind of free writing of three-dimensional Si patterns named focused-ion-beam chemical vapor deposition (FIB-CVD). CPS molecules facilitated the advancement of this method. The third method, described in 8.3, is nanoimprinting of silicon. Well-defined silicon patterns with a high aspect ratio and sharp edges were directly formed by imprinting of liquid silicon. Both dotted and lined patterns whose size ranges from 1 mm to 100 nm were obtained, suggesting that their size could be further reduced.
KeywordsArea-selective deposition Hamaker constant Polysilane Focused-ion-beam (FIB)-CVD Nanoimprinting
- 1.S.M. Sze, Semiconductor Devices: Physics and Technology, Chapter 11 (Wiley, 2008)Google Scholar