First class Fabrication of single crystalline Silicon Etching

First class

Fabrication of single crystalline Silicon

Etching of Si • 大部分的濕式蝕刻是等向性的，但有些濕式蝕刻是非等向性的 蝕刻液 KOH: H 2 O KOH EDP N 2 H 4: H 2 O NH 4 OH 蝕刻速率 (μm/hour) 溫度 ( C) Si(100) Si(111) 80 75 110 118 75 84 25 42 51 176 24 126 39 66 57 99 8 0. 21 0. 5 1. 25 11 1

Slip system (滑移系統)

Liquid crystal

• 液晶異向性 • 光學(Optical) • 雙折射(Birefringence) • n=n//-n • 介電常數(Dielectric Contant) • = //- • 黏滯性(Viscosity) • 1， 2， 3 • 彈性(Elasticity) • k 11，k 22， k 33 • 磁化率(Susceptibility) • = //- • 導電率(Susceptibility) • //，

Crystals and Properties p(The symmetry of) Any physical property of a crystal has at least the symmetry of the crystal p. Crystals are anisotropic with respect to most properties p. The growth shape of a (well grown) crystal has the internal symmetry of the crystal p. Polycrystalline materials or aggregates of crystals may have isotropic properties (due to averaging of may randomly oriented grains) p. The properties of a crystal can be drastically altered in the presence of defects (starting with crystal defects)