Fa|2006 Fundamentals of Semiconductor Physics 万歆 Zhejiang Institute of Modern Physics xinwan@zimpzju.edu.cn http://zimp.zju.edu.cn/xinwan/
Fundamentals of Semiconductor Physics 万 歆 Zhejiang Institute of Modern Physics xinwan@zimp.zju.edu.cn http://zimp.zju.edu.cn/~xinwan/ Fall 2006
Five-Point plan for success e Pursue your passions e Venture where you have never ventured before e Pace yourself e Serve others e Have lots of fun Princeton President Shirley M. tilghman
Five-Point Plan for Success ☺ Pursue your passions ☺ Venture where you have never ventured before ☺ Pace yourself ☺ Serve others ☺ Have lots of fun -- Princeton President Shirley M. Tilghman
Chapter 2. Silicon Technology TWo foundations of successful engineering Mastery of physics concepts Perfect technology -means to transfer concepts into usefu structures Total 3 hours
Chapter 2. Silicon Technology Two foundations of successful engineering: – Mastery of physics concepts – Perfect technology – means to transfer concepts into useful structures. Total 3 hours
IC card 游 杭州 HANG ZHOU CPU EEPROM 64kb ROMIRAM
IC Card
Si Ge& GaAs Technological evolution began with gemanium in 1940s Band gap e =0.67eV At 300 K, intrinsic carrier density n; =2.5 x 1013 cm-3 n; arises fast with T, due to sm-ig1015 cm-3 at 400 K Device not useful when intrinsic carrier concentration is comparable to dopant density Research efforts shifted to silicon(Ea=1.12 ev) and GaAs(ea=1.42 e) in 1950s
Si, Ge & GaAs • Technological evolution began with gemanium in 1940s. – Band gap Eg = 0.67 eV – At 300 K, intrinsic carrier density ni = 2.5 x 1013 cm-3 – ni arises fast with T, due to small Eg – ~1015 cm-3 at 400 K – Device not useful when intrinsic carrier concentration is comparable to dopant density. • Research efforts shifted to silicon (Eg = 1.12 eV) and GaAs (Eg = 1.42 eV) in 1950s
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