Ohta Tomohiko

Title: Ohta Tomohiko: Innovator in Semiconductor Technology

Introduction

Ohta Tomohiko is a notable inventor based in Fukushima-ken, Japan. He has made significant contributions to the field of semiconductor technology, particularly in the preparation of silicon single crystals. With a total of two patents to his name, his work has had a considerable impact on the industry.

Latest Patents

Ohta's latest patents focus on the development of a fused silica glass crucible and an improved method for the preparation of semiconductor silicon single crystals of N-type by the Czochralski process. His innovative approach addresses the issue of delayed oxygen-related defects (OSFs) in single crystals, which can occur even after prolonged storage at room temperature. Ohta discovered that the presence of aluminum in the silicon melt contained within the crucible helps suppress these defects, while copper impurities can exacerbate the problem. His invention proposes using a crucible with an inner surface layer that contains aluminum at an average concentration of 40 to 500 ppm by weight, while keeping copper content below 0.5 ppb by weight. Additionally, if the crucible lacks sufficient aluminum, he suggests introducing aluminum as a dopant into the silicon melt to ensure adequate levels for defect suppression.

Career Highlights

Throughout his career, Ohta has worked with prominent companies in the semiconductor industry, including Shin-Etsu Handotai Co., Ltd. and Shin-Etsu Quartz Products Co., Ltd. His experience in these organizations has allowed him to refine his expertise and contribute to advancements in semiconductor manufacturing processes.

Collaborations

Ohta has collaborated with notable colleagues such as Wataru Sato and Masahiro Sakurada. Their combined efforts have furthered the development of innovative solutions in the semiconductor field.

Conclusion

Ohta Tomohiko's contributions to semiconductor technology, particularly through his patents on fused silica glass crucibles and methods for preparing silicon single crystals, highlight his role as a key innovator in the industry. His work continues to influence advancements in semiconductor manufacturing processes.