Shimpei Iijima

Title: The Innovations of Shimpei Iijima

Introduction

Shimpei Iijima is a notable inventor based in Akishima, Japan. He has made significant contributions to the field of semiconductor technology, holding a total of 5 patents. His work has been instrumental in advancing memory device technology.

Latest Patents

One of Iijima's latest patents is a semiconductor memory device that features a static random access memory. This invention introduces a technique that reduces electrode resistance by widening the effective area of an electrode in a cell for a standard potential supply connected to the memory cell. Additionally, it offers a method to minimize the memory cell area by decreasing the space required for separation between the electrode in a cell and adjacent electrodes. The design incorporates two transfer MOS transistors of a first conductivity type and two driver MOS transistors. A conductive layer is strategically placed above these transistors to stabilize the source potential of the driver MOS transistors to standard potential, effectively covering the memory cell. The separation process utilizes a photo-mask with an optically transparent substrate, which includes a pattern of phase shifter regions for light transmission phase inversion.

Another significant patent involves a method for manufacturing semiconductor devices. In this process, a boron-doped amorphous silicon film is created using chemical vapor deposition (CVD) under specific conditions. This method allows for the formation of a pn junction that is much shallower than those produced by traditional techniques, enhancing the efficiency of semiconductor devices.

Career Highlights

Throughout his career, Shimpei Iijima has worked with prominent companies such as Hitachi, Ltd. and Hitachi VLSI Engineering Corporation. His experience in these organizations has contributed to his expertise in semiconductor technology and innovation.

Collaborations

Iijima has collaborated with notable colleagues, including Tokuo Kure and Eiji Takeda. These partnerships have fostered a collaborative environment that has led to significant advancements in their respective fields.

Conclusion

Shimpei Iijima's contributions to semiconductor technology and his innovative patents have made a lasting impact on the industry. His work continues to influence the development of advanced memory devices and manufacturing methods.