IBM Researcher Wins Kyoto Prize for DRAM Invention

Robert Heath Dennard, an IBM Fellow, is named a recipient of the 2013 Kyoto Prize for his achievements in electronics.

IBM researcher Dr. Robert Heath Dennard has won one of Japan's most coveted awards for his accomplishments in electronics.

Dennard, an IBM Fellow, was named a Kyoto Prize laureate on June 21, winning the Advanced Technology Prize in the field of electronics.

The Kyoto Prize is an international award bestowed by The Inamori Foundation to honor those who have contributed significantly to the scientific, cultural and spiritual betterment of humankind. At a November ceremony in Kyoto, Japan, each laureate will receive a diploma, a 20-karat gold Kyoto Prize medal and a cash gift of 50 million yen—which is equivalent to about $600,000—in recognition of lifelong contributions to society.

Dennard, 80, invented the basic structure of dynamic random access memory (DRAM), which is now extensively used as one of the integrated circuit (IC) memory systems. His innovation has immensely increased the capacity of digital information storage, leading to dramatic progress in information and telecommunications technology.

Dennard and his colleagues also proposed guidelines, called "scaling theory," to miniaturize metal oxide semiconductor (MOS) field-effect transistors (FETs), which play key roles in most ICs, including DRAM, thereby promoting the amazing advance in IC technology.

Essentially, what Dennard and his coworkers did was study how FET characteristics changed when they were scaled down and then the team proposed their miniaturization guidelines based on these studies. These proposals facilitated the integration of more FETs on a single chip, increasing DRAM storage capacity more than one million-fold, while permitting drastic improvement in the speed and performance of microprocessors and other ICs. These achievements brought about key developments in integrated circuit technologies, which provided the essential foundation for vast progress in information and communications equipment.

Dennard began working on memory ICs for computers in the 1960s and invented the basic DRAM structure in 1967. Its fundamental memory unit, or cell, consists of one transistor and one capacitor; each cell stores one bit of data as "1" or "0" by controlling the presence or absence of an electric charge on the capacitor. Cells are arranged on a chip in a matrix form and connected to gridlike wire lines to create a DRAM. The system is called random access memory because it permits any memory cell to be accessed in random order by the selection of a specific horizontal "word" line and a vertical "bit" line, unlike the sequential access memory provided by tape storage.

To store digital information, one bit of data, "1" or "0," is written in each cell by supplying or removing an electric charge on its capacitor through the transistor. Because the charge thus stored on each capacitor gradually drains away, it is necessary to refresh the capacitor periodically, leading to the name "dynamic" RAM, or DRAM. To read the binary data of a cell, the presence or absence of a stored charge on the capacitor is detected by precisely measuring a change in the electric potential of the bit line.

In 1970, a 1k-bit DRAM chip using a three-transistor cell was commercially released, while Dennard's one-transistor design made its market debut in 1973. Since then, all the DRAMs have been produced by incorporating the single-transistor structure.

In addition to Dennard, the 2013 Kyoto Prize also went to Dr. Masatoshi Nei and Cecil Taylor. Nei, 82, won his prize in the category of Basic Sciences, specifically biological sciences. Nei, an evolutionary biologist at Pennsylvania State University, made it possible to discuss evolutionary divergence, genetic diversity and the mode of selection on genes in a quantitative manner by devising diverse statistical methods such as Nei's genetic distance and applying them to molecular data. Using these methods, Nei's research has yielded important contributions to molecular evolutionary biology, as well as many other academic disciplines including ecology and conservation biology, and helped with understanding the evolutionary mechanism of genes, such as positive selection.

Winning in the Arts & Philosophy category, music visionary Cecil Taylor, 84, is considered one of the most original pianists in the history of jazz. He developed his innovative improvisation departing from conventional idioms through distinctive musical constructions and percussive renditions, thereby opening new possibilities in jazz. The Kyoto Prize committee noted that his "unsurpassed virtuosity and strong will inject an intense, vital force into his music, which has exerted a profound influence on a broad range of musical genres."

The Inamori Foundation was started by Japanese philanthropist Dr. Kazuo Inamori, founder of Kyocera Corp. and KDDI Corp., and director and chairman emeritus of Japan Airlines. Including this year's laureates, 93 individuals and one organization—The Nobel Foundation—have been honored with the Kyoto Prize. In addition to the Nobel Foundation, other previous recipients include Dr. Alan Kay, Dr. Jane Goodall, Dr. Ivan Sutherland, Dr. Shinya Yamanaka and Akira Kurosawa. Moreover, seven Kyoto Prize laureates have also been honored with the Nobel Prize.