John H Wohlgemuth

Title: Innovations of John H Wohlgemuth in Gallium Arsenide Crystal Growth

Introduction

John H Wohlgemuth is a notable inventor based in Acton, MA (US), recognized for his contributions to the field of semiconductor technology. He holds a patent that significantly advances the process of gallium arsenide (GaAs) crystal growth, which is crucial for various electronic applications.

Latest Patents

Wohlgemuth's patent focuses on a process for producing semi-insulating GaAs crystals with low dislocation density without the need for doping of PBN crucibles. This innovative method allows for the in situ annealing of the crystal after growth. The process is a variant of the Heat Exchanger Method (HEM) disclosed in U.S. Pat. No. 3,898,051. The resulting crack-free, semi-insulating GaAs crystals are grown from presynthesized undoped GaAs meltstock in sealed quartz crucibles, eliminating the need for an encapsulant. One notable aspect of his invention involves the seeded growth of <100> orientation crystals, which exhibit a dislocation density 1-2 orders of magnitude less than that of the seed. Additionally, crystals with fewer than 500 dislocations/cm² in their center column can be grown without a seed.

Career Highlights

Wohlgemuth is associated with Ghemini Technologies, where he applies his expertise in semiconductor materials. His work has contributed to advancements in the production of high-quality GaAs crystals, which are essential for the development of efficient electronic devices.

Collaborations

Wohlgemuth has collaborated with notable colleagues, including Chandra P Khattak and Vernon E White, who have also contributed to the field of semiconductor technology.

Conclusion

John H Wohlgemuth's innovative work in gallium arsenide crystal growth represents a significant advancement in semiconductor technology. His contributions continue to influence the development of high-performance electronic materials.