Keiichi Morita

Title: Keiichi Morita: Innovator in Semiconductor Technology

Introduction

Keiichi Morita is a prominent inventor based in Hitachi, Japan. He has made significant contributions to the field of semiconductor technology, holding a total of 6 patents. His work focuses on improving the efficiency and performance of semiconductor devices, particularly in solar cell technology.

Latest Patents

One of Morita's latest patents is a method of making a light-receiving diode. This innovative method involves manufacturing a solar cell that includes a p-n junction formed in a semiconductor substrate. Impurity ions are implanted through a mask in the form of an oxide film, which covers the light-receiving surface of the semiconductor substrate, except for the electrode forming part. This technique results in a p-n junction that is deep beneath the electrode but shallow in the remaining area, enhancing spectral sensitivity in the short wavelength range. Additionally, the oxide film serves as a passivation film, preventing the shortening of minority carrier lifetime due to heat treatment, thus reducing the electron-hole recombination rate at the light-receiving surface.

Another notable patent is related to a semiconductor device that features a solder joint between a semiconductor substrate and an electrode. In this invention, the principal surface of the semiconductor substrate, where an n-type semiconductor layer is exposed, is bonded to the electrode using brazing solder. The solder consists of aluminum solder on the semiconductor side and copper solder on the electrode side. This design allows for solid phase adhesion between aluminum and copper at temperatures below the eutectic temperature of 548°C, enabling low-temperature soldering of the semiconductor substrate to the electrode.

Career Highlights

Keiichi Morita is associated with Hitachi, Ltd., a leading company in technology and innovation. His work has significantly impacted the development of semiconductor devices, particularly in enhancing their efficiency and reliability.

Collaborations

Morita has collaborated with notable colleagues, including Keiichi Kuniya and Hideyuki Yagi. Their combined expertise has contributed to advancements in semiconductor technology.

Conclusion

Keiichi Morita's innovative work in semiconductor technology, particularly in solar cells and solder joints, showcases his commitment to advancing the field. His contributions continue to influence the development of efficient and reliable semiconductor devices.