Advantages of silicon Key: ability to form on silicon a stable, controllable oxide film(silicon oxide, Sio2) that has excellent insulating properties Selective etching HF dissolves Sio, not si SiO2 shields Si from doping(photosensitive polymer films are used to define shielded regions)
Advantages of Silicon Key: ability to form on silicon a stable, controllable oxide film (silicon oxide, SiO2 ) that has excellent insulating properties. • Selective etching: HF dissolves SiO2 not Si • SiO2 shields Si from doping (photosensitive polymer films are used to define shielded regions)
Wafer-Chips- Devices 栅极 约50~1000芯片 源极 漏极 10-10 个器件 MOSEET w===二二二 Ium -lOum 2gm-10 双极型 I mm-20 mm 晶体管 100mm-300 mm 集电极 (0.5mm-0.755mm) 基极 发射极 (a)半导体晶片 b)芯片 (c) MOSFET和双极型晶体管 图14.2晶片和单一器件的大小比较
Wafer – Chips - Devices
The whole process s 晶片 起始材料 蒸馏 与 掩模版组 薄膜形成 还原 多晶半导体 图形曝光 杂质掺杂 晶体生长 单晶 刻蚀 研磨、切割 抛光 片完成 晶片
The Whole Process
Planar Process ha Formation of a masking oxide Si rely remo layer Its selective removal Deposition of dopant atoms on Dopant atoms deposited or near the wafer surface A on exposed surfaces Their diffusion into the exposed silicon regions Dopant atoms diffuse into Si t not appreciably into Sio
Planar Process • Formation of a masking oxide layer • Its selective removal • Deposition of dopant atoms on or near the wafer surface • Their diffusion into the exposed silicon regions
Czochralski process Solid-liqu o Molten interface silicon silicon Figure 2.3 Formation of a single-crystal semiconductor ingot by the Czochralski process:(a)initiation of the crystal by a seed held at the melt surface, (b)withdrawal of the seed"pulls"a single crystal
Czochralski Process