Dramatic Reduction of Surface Defects and Particles on pHEMT epi-wafers grown by MOVPE for higher yield of Transistors
Hiroyuki Kamogawa, Hisataka Nagai, Kazuto Takano and Yohei Otoki
Semiconductor Department, Hitachi Cable Ltd.,880 Isagozawa, Hitachi, 319-1418, JAPAN Hitachi Cable America, 2665 N 1st St. 200, San Jose, CA, 95134 Phone: 408-324-1880 E-mail: Otoki@hitachi-cable.com
Keywords:GaAs, pHEMTs, epi-wafers, MOVPE, surface defects,
A dramatic reduction in the defect density has been achieved on 6” diameter pHEMT epi-wafers by using face down type MOVPE reactors. The defects were analyzed and found to come from deposition in the reactor. The deposition temperature was varied the experiment and found it was occurred in lower temperature than we thought, under 250C incase we used TEG. Based on these results, the temperature distribution of the reactor was redesigned. As a result, defect density was reduced to the extremely low value of 0.2/ cm2.