Multiwafer molecular beam epitaxy for high volume production of GaAs/AlGaAs heterojunction bipolar transistor wafers

Circuits incorporating GaAs/AlGaAs heterojunction bipolar transistors (HBTs) are being increasingly used in commercial applications with volume requirements that can only be met using multiwafer reactors. HBT wafers grown in single and multiwafer molecular beam epitaxy (MBE) reactors are found to be very similar in terms of both material characteristics and resultant device performance. Postgrowth defect levels are reduced by an order of magnitude with the multiwafer system compared to single wafer systems and are similar to those obtained on commercially purchased metal organic chemical vapor deposition wafers. Multiwafer MBE systems are thus shown to be a viable means for the high volume production of HBT wafers.