6.152J3.155J Liquid encapsulated CZ or Bridgman growth 6.12J/3.155J Microelectronic processing because vapor pressure at Tm=12380C: 0.001 10 atmospheres B2O3 minimizes loss of As v A 1 cm/hr Crucible p≈100M。cm 104 defects/cm2 Pressure may 100+ dislocations /cm2 ild to 20 HPLEC Crit. resolved 0.21 0.17 GaAs12380.07 04 GaAs cannot dissipate heat GaAs cannot take stress grow Floating zone For very high purity Si(not used for GaAs) Top seed molten part 仓6.152J/3.155J 12 23 Nov.26 , 2003 6.12J / 3.155J Microelectronic processing Liquid encapsulated CZ or Bridgman growth …because Ga As vapor pressure at Tm = 12380C: 0.001 10 atmospheres. Seed BN Crucible (keep Si out) B2O3 liquid plug GaAs + As r § 100 MWcm 104 defects/cm2 100+ dislocations /cm2 B2O3 minimizes loss of As; v § 1 cm/hr. Pressure may build to 20 atm: HPLEC Tmelt k Crit. resolved shear stress Si 1414 0.21 1.85 Ge 960 0.17 0.70 GaAs 1238 0.07 0.4 GaAs cannot dissipate heat; grow slowly GaAs cannot take stress; grow slowly 24 Nov.26 , 2003 6.12J / 3.155J Microelectronic processing Floating zone For very high purity Si (not used for GaAs) high-purity crystal Polycrystal feed rod seed Top seed (molten part supported by upper crystal) seed high-purity crystal Bottom seed