Isao Sakama

A 0.05×0.05mm2 RFID Chip with Easily Scaled-Down ID-Memory

An ultra-small RFID chip uses an electron beam for writing 1T memory cells. A 90nm SOI CMOS process and double-surface electrode chip structures enable the design of 0.05times0.05mm2 and 5mum-thick RFID chips with small, low-cost and highly-reliable 128b ID-memory. The chip is verified at a carrier frequency of 2.45GHz with measured communication distance of 300mm.

Electron Beam Direct Writing Technology for 64-Mb DRAM LSIs

This paper describes the electron beam direct writing technology for 64-Mb DRAM LSIs including a resist process for 0.3-µm resolution, the prevention of the charging problem by a conducting polymer, and proximity effect correction by both the pattern classification method and the subsidiary exposure method. A large amount of pattern data is processed after dividing the whole chip data into peripheral circuits and 256-kb memory mats. An experimental 64-Mb DRAM LSI is fabricated by these technologies.