Dr. Robert Heath Dennard invented the basic structure of Dynamic Random Access Memory (DRAM), which is now extensively utilized as one of 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. Dr. Dennard and his colleagues also proposed guidelines, called “scaling theory”, to miniaturize field-effect transistors, which play key roles in most ICs, including DRAM, thereby promoting the amazing advance in IC technology.
Field-Effect Transistor Memory, U.S. Patent 3,387,286, June 4, 1968.
Design of Ion-Implanted MOSFETs with Very Small Physical Dimensions (with Gaensslen, F. H. et al.), IEEE Journal of Solid-State Circuits SC9: 256-268, 1974.
Fabrication of a Miniature 8K-Bit Memory Chip Using Electron-Beam Exposure (Yu, H. N., Dennard, R. H. et al.), Journal of Vacuum Science and Technology 12: 1297-1300, 1975.
Evolution of the MOSFET Dynamic RAM – A Personal View, IEEE Transactions on Electron Devices 31: 1549-1555, 1984.
Scaling Challenges for DRAM and Microprocessors in the 21st Century, in Electrochemical Society Proceedings 97-3: 519-532, 1997.
Dr. Robert Heath Dennard invented the basic structure of the Dynamic Random Access Memory (DRAM) which is now utilized extensively as one of integrated circuit (IC) memory systems. This innovation has immensely increased the capacity of digital information storage, leading to dramatic progress in information and telecommunications technology. Dr. Dennard and his colleagues also proposed design guidelines for miniaturizing MOS (metal oxide semiconductor) field-effect transistors (FETs), which play key roles in most ICs, including DRAM, thereby promoting the amazing advance in IC technology.
Dr. 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 FET (hereinafter, “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 grid-like 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, 1k-bit DRAM chip using a three-transistor cell was commercially released, while Dr. 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 his DRAM invention, Dr. Dennard and his coworkers studied how FET characteristics changed when they were scaled down, and proposed design guidelines (scaling theory) useful for FET miniaturization. This 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 by Dr. Dennard brought about remarkable developments in integrated circuit technologies, which provided the essential foundation for tremendous progress in information and communications equipments.
For these reasons, the Inamori Foundation is pleased to present the 2013 Kyoto Prize in Advanced Technology to Dr. Robert Heath Dennard.
Born in Texas in 1932 during the great depression, I grew up in a family of modest means on a farm without electricity and started my education in a one-room schoolhouse. How I went on from there to a notable career in electrical engineering may seem amazing. This talk describes the key steps along the way which tempered my character and attitudes, and led me to the educational path behind my success.
I think I was very fortunate to have an opportunity to join IBM Research at the time the field of computing was growing rapidly and, moreover, to have a chance to get into microelectronics near its beginning. I will describe what inspired me to invent DRAM and the motivation to keep working on my ideas until I reached the simple structure I envisioned.
My contributions to the scaling principles of microelectronics came early in a new program with an ambitious goal of greatly reducing the cost of computer memory, which required us to make DRAM with much smaller dimensions. I led an investigation, with a few coworkers, of how the transistors used in DRAM and other microelectronics circuits would work with such greatly reduced size. We devised a set of scaling rules which made them function properly and operate faster with much less energy consumption. Test versions of highly-scaled DRAM were built to show it could actually be done. I will review the impact of this work which led to programs with very large scale integrated circuits (VLSI) in Japan and around the world.
Reflecting on why I was successful in my career, and talking with other inventors, I found some traits common to creative people in engineering and science. My conclusion and slogan is “Attitude is Everything”. This talk explains what that means and how I came to develop the attitude that drives my work.
I will conclude by discussing the importance of addressing long-range worldwide future problems such as clean energy supply, preserving our environment, and minimizing or managing global warming for this century and beyond. I hope the computing and communications capability developed by my generation will be helpful, but I realize the complexity and difficulty of this challenge will require everyone in all disciplines to solve.