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HB-GaAs ( 10 0 )片要偏离生长截面 5 4.7°～ 60°切割 (〈10 0〉和〈111〉之间的夹角是 5 4.7°)。如果籽晶方向与〈10 0〉之间的夹角少于 5 4.7°,称为反偏籽晶。而采用大于 5 4.7°角生长的单晶切割比较困难 ,尤其是厚度小于 3 0 0 μm的晶片。为了减少切割难度 ,可生长反偏籽晶的单晶 ,但要保证单晶能割出Φ2″( 10 0 )圆片 ,必须增加单晶锭的截面积。由于GaAs的热导率小 ,大截面单晶生长要困难得多。通过改变固液截面附近的加热元件结构 ,在特定方向加强了散热 ,延伸了温度梯度的线性范围 ,使用反偏籽晶 ,成功地生长了Φ2″HB GaAs单晶。和正偏籽晶单晶相比 ,这些单晶锭的切割破损率减少了 2 4% ,每 10 0mm长度出片数增加了 3 0 %。
The HB-GaAs (10 0) slice should be cut off from 4.7 ° to 60 ° of the growth cross section (the angle between <10 0> and <111> is 5 4.7 °). If the angle between the seed direction and <10 0> is less than 5 4.7 °, it is called reverse bias seed. Single-crystal cutting with greater than 5 4.7 ° growth is more difficult, especially for wafers with thickness less than 300 μm. In order to reduce the difficulty of cutting, it is possible to grow monoclinic crystals with reverse bias, but it is necessary to increase the cross-sectional area of the monocrystalline ingot in order to ensure that the single crystal can cut out a Φ2 “(100) wafer. Due to the small thermal conductivity of GaAs, Section single crystal growth is much more difficult by changing the structure of the heating element near the solid-liquid cross section to enhance the heat dissipation in a particular direction, extending the linear range of the temperature gradient, the use of reverse bias seed crystals successfully grown Φ2 ”HB GaAs single crystal. These single crystal ingots showed a 24% reduction in the cutting damage and a 30% increase in the number of chips per 100 mm length compared to normal-bias seed crystals.