Abstract

The "VLSI revolution" that is opening a new epoch in the electronics industry has made such remarkable progress that now 108 - 109 transistors can be fabricated on a single chip. VLSI microfabrication technologies are being pushed to new extremes by the DRAM community, thereby expediting research on 256 Mbit DRAMs using the 0.2 μm design rule. Giga-bit DRAMs and sophisticated ULSI processors using 0.1 μm Si-MOSFETs could possibly appear in the latter half of the 1990s. Recently, a very high speed ring oscillator has achieved 10 psec/gate for 77 K operation[1]. In the field of advanced bipolar transistors, a 64 GHz cut-off frequency has been reported[2]. These speeds are comparable to those of conventional quantum devices such as HEMTs (High electron mobility transistors)[3], JJs (Josephson junction devices)[4], and STrs (Superconducting transistors)[5] as shown in Fig. 1. In addition, device operation of 7-10 nm Si-MOSFETs (corresponding to 1-16 Tera-bit memories) [6] and single electron transistors (SET) [7] have been confirmed, which implies an increased importance for nano-meter fabrication technology. Si devices have a promising future, which will pave the way to the 21st century.

© 1993 Optical Society of America