Tsugio Makimoto

The Rising Wave of Field Programmability

There have been alternating cycles of standardization and customization in the semiconductor industry, which I first noticed in 1987. It later appeared in Electronics Weekly (U.K.) in January 1991 under the name of Makimoto’s wave. As shown in Fig. 1, there have been changes in direction roughly every ten years.

Automation in semiconductor manufacturing

Some backgrounds and trends of semiconductor technology will be reviewed in conjunction with production automation. Experiences are presented for the case of the advanced MOS wafer processing area, including the basic philosophy and equipment implementation. History of the automation in assembling area will follow including some existing examples. Semiconductor technology keeps changing towards smaller dimension, larger die size, larger number of pins, and larger number of product types. One of the big problems lies in the fact that the throughput of equipments is getting lower as the geometry getting finer, and major breakthrough is expected. Future opportunities and related problems will be discussed.

Self-isolated bipolar transistors in integrated circuits

The possibility of implementing bipolar transistors, and hence diodes, in integrated circuits in a self-isolated form has been proposed by one of the authors and independently by B. T. Murphy et al. The present paper is concerned with some of the experimental results of the proposed structures. A p-type epitaxial layer is grown on a p-type substrate where localized n+-layers are buried, and there is no need for additional isolation diffusion besides n+-collector contact diffusion. The higher packing density and the simlicity in processing resulting from the above structures are desirable features for LSI

Self-Isolated Transistor Structures of Bipolar Integrated Circuits

Self-isolated transistor structures for bipolar integrated circuits are proposed. Some of the advantageous features of the proposed structures are; negligible minority carrier storage in collector region, low collector series resistance and large current handling capability, high packing density, and ease of processing. Cutoff frequency of about 600 MHz was observed for the graded base structure, and about 400 MHz for the uniform base structure. It is also shown that the current handling capability is improved. Epitaxial growth is one of the critical steps in producing self-isolated bipolar integrated circuits. A discussion is given for the specification of the epitaxial layer. In order to minimize the back diffusion from the buried layer to the base, a new possible way of processing is proposed which makes use of the simultaneous diffusion of Ga, As, and P.

Experimental Study on the Out-Diffusion of Sb from Ge and Its Application to Transistors

An analytical solution for the double diffusion problem which consists of in- and out-diffusion is given. An experimental method to get the evaporation velocity, K, is proposed. K is obtained as 2.9×10-8 cms-1 at 700°C and has the activation energy of 1.75 eV. The double diffusion method is applied to Ge base-diffused transistors. Changes in some electrical characteristics with the out-diffusion conditions are given, which are in satisfactory agreement with the theory. The impurity distribution profile of the base layer is improved by making use of the double diffusion method. The improvement ratio is obtained experimentally and compared with the theory.

Market and technology outlook into the year 2000 [semiconductor manufacturing]

Technological improvements to make fine geometries have been one of the key factors in developing high-performance, low-power, and highly integrated semiconductor devices, which have led to produce high-performance, low-power portable, electronic equipment. This trend in electronic equipment has been changing our daily lifestyle which in turn is driving demand for further improvements in semiconductor devices. However, as geometry becomes finer, the amount of investment required to manufacture semiconductors is escalating. This paper discusses market outlook beyond the year 2000, and reviews enabling technologies. A new figure of merit is discussed which provides a guiding principle for technological progress in the new age, which the author calls the nomadic age.

A high performance silicon gate E/D MOS LSI using ion implantation

Silicon gate technology itself gives higher speed and lower power drain than aluminum gate technologies due to its low threshold voltage and self-aligned structure. Further improvements can be accomplished by using inverters of E/D structure (enhancement driver-depletion load) instead of E/E structure (enhancement driver-enhancement load). Ion implantation technology has made it possible to build both enhancement and depletion type MOS FETs on a single chip by adding only one mask to the conventional MOS IC process.