Hisashi Shichijo

Title: Innovations of Hisashi Shichijo: Pioneering Technologies in Transistors and Monitoring Circuits

Introduction: Hisashi Shichijo, an accomplished inventor based in Plano, TX, has made significant contributions to the field of semiconductor technology. With an impressive portfolio of 24 patents, he has led the way in developing advanced circuits and transistors that enhance the functionality and efficiency of modern electronics.

Latest Patents: Among his latest innovations are two notable patents. The first is the DEMOS transistor with STI and compensated well in drain. This innovative design features a drain extended MOS (DEMOS) transistor that separates the drain contact from the gate with an element of field oxide. It also includes a compensation region of opposite polarity in the drain under the gate. Importantly, this transistor can be fabricated in a CMOS integrated circuit (IC) without the need for additional processing steps. Both n-channel and p-channel variations can be produced in CMOS ICs featuring an n-type buried layer, and the design is compatible with SOI wafer technology. The ability to vary the compensation region's width allows the handling of multiple signals with different voltage levels within a single IC, all while maintaining fabrication efficiency.

The second patent involves a process and temperature insensitive flicker noise monitor circuit. This apparatus is designed to facilitate the monitoring of defects in wafers by embedding a monitoring circuit on an area of each wafer. It includes representative devices that mirror similar devices located within the die area. Any defects present in these representative devices generate noise, resulting in an imbalance in a differential signal that can be measured. A digitizing circuit utilizes a common mode voltage as a reference to discern this imbalance, converting the differential signal into digital data that indicates the level of noise due to defects. The stored digital bit stream can be compared against a reference to ascertain if defects fall within an acceptable range.

Career Highlights: Hisashi Shichijo's career is marked by his tenure at Texas Instruments Corporation, where he has contributed to groundbreaking technologies in semiconductor devices. His inventions not only enhance performance but also streamline production processes, demonstrating his commitment to innovation in the field.

Collaborations: Throughout his career, Shichijo has collaborated with notable colleagues like Zhiliang Julian Chen and Kuok Y Ling. Together, they have pursued advancements in transistor design and electronic monitoring systems, reinforcing the importance of teamwork in fostering innovation.

Conclusion: Hisashi Shichijo's work exemplifies the critical role that inventors play in advancing technology. With his 24 patents, he continues to influence the future of semiconductor devices, ensuring that modern electronics continue to evolve. His achievements serve as an inspiration for future inventors seeking to make their mark in the world of technology.