赤外センサ用Mg₂Si結晶の融液成長

抄録

  We have grown high purity n-type Mg₂Si single crystals by the vertical Bridgman growth method using a pyrolitic graphite (PG) crucible and high purity Mg (5N or 6N-up) and Si (10N-grade) source metals. The saturated electron concentration and Hall mobility of the grown crystals were (1 - 2) × 10¹⁵ cm^-3 and 480 - 485 cm²/Vs at room temperature. Mg₂Si substrates prepared from the crystals had an enough crystalline quality to fabricate pn-junction photodiodes (PDs). The ring-electrode-type, pn-junction PD fabricated by the rapid thermal diffusion of Ag and conventional lift-off process showed a good photoresponse below 2 μm in wavelength. The detectivity D^* of 1 × 10¹² cmHz^1/2/W has been achieved with the PDs under 1.31 μm laser diode (LD) bombardment at 77K.