This paper describes a 0.35µm SOI-CMOS gate array using partially-depleted transistors. The gate array adopts the field-shield isolation technique with body-tied structures to suppress floating-body problems such as: (1) kink characteristics in drain currents, (2) low break-down voltage, and (3) frequency-dependent delay time. By optimizing the basic-cell layout and power-line wiring, the SOI-CMOS gate array also allows the use of the cell libraries and the design methodologies compatible with bulk-CMOS gate arrays. An ATM (Asynchronous Transfer Mode) physical-layer processing LSI was fabricated using a 0.35µm SOI-CMOS gate array with 560k raw gates. The LSI operated at 156 Mbps at 2.0 V, while consuming 71% less power than using a typical 0.35µm 3.3 V bulk-CMOS gate array.

We propose a novel capacitorless twin-transistor random access memory (TTRAM). The 2 Mb test device has been fabricated on 130 nm SOI-CMOS process. We demonstrate the TTRAM cell has two data-storage states and confirm the data retention time of 100 ms at 80. TTRAM process is compatible with the conventional SOI-CMOS and never requires any additional processes. A 6.1 ns row-access time is achieved and 250 MHz operation can be realized by using 2 bank 8 b-burst mode.

A high-speed silicon-on-insulator (SOI) of a 1/8 frequency divider and a 64-bit adder were realized using an optimized gate-overlapped LDD and a self-aligned titanium silicide (TiSi2) source-drain structure. The advantages of the delay time and power consumption were analyzed by circuit simulation. The maximum operation frequency of the SOI divider is 2.9 GHz at 3.3 V. The SOI divider operates about 1.6 times faster than the bulk-Si divider. The power consumption of the SOI divider at the maximum operating frequency is about 60% of that of the bulk divider. On the other hand, the speed of the SOI adder is 1.9 nsec at 3.3 V. The SOI adder speed is about 1.3 times faster than the bulk adder. The power consumption of the SOI adder is about 80% of that of the bulk divider. It was found that the high speed, low power features of the SOI divider were due to the pass transistor which had low junction capacitance and little substrate bias effects, in addition to the low wiring capacitance and low fanout capacitance compared to the bulk adder. As a result, it is suggested that SOI circuits using pass transistor have a potential for GHz level systems and it is expected they will be applied to handy communication systems and portable computers used in the multimedia era.

Instability of SRAM memory cells derived from aggressive technology scaling has been recently one of the most significant issues. Although a 7T-SRAM cell with an area-tolerable separated read port improves read margins even at sub-1V, it unfortunately results in degradation of write margins. In order to assist the write operation, we address a new memory cell employing a look-ahead body-bias which dynamically controls the threshold voltage. Simulation results have shown improvement in both the write margins and access time without increasing the leakage power derived from the body-bias.

A low-power microcontroller has been developed with 0.10 µm bulk compatible body-tied SOI technology. For this work, only two new masks are required. For the other layers, existing masks of a prior work developed with 0.18 µm bulk CMOS technology can be applied without any changes. With the SOI technology, the high-speed operation of over 600 MHz has been achieved at a supply voltage of 1.2 V, which is 1.5 times faster than prior work. Also, a five times improvement in the power-delay product has been achieved at a supply voltage 0.8 V. Moreover, the compatibility of the SOI technology with bulk CMOS has been verified, because all circuit blocks of the chip, including logic, memory, analog circuit, and PLL, are completely functional, even though only two new masks are used.

In this paper, we propose an Active Body-biasing Controlled (ABC)-Bootstrap PTL (Pass-Transistor Logic) on PD-SOI for ultra low power design. Although simply lowering the supply voltage (VDD) causes a lack of driving power, our boosted voltage scheme employing a strong capacitive coupling with ABC-SOI improves a driving power and allows lower voltage operation. We also present an SOI-SRAM design boosting the word line (WL) voltage higher than VDD in short transition time without dual power supply rails. Simulation results have shown improvement in both the delay time and power consumption.

Partially depleted SOI technology with body-tied hybrid trench isolation was developed in order to counteract floating body effects which offers negative impact on the drive current of transistors and the stability of circuit operation while maintaining SOI's specific merits such as high speed operation and low power consumption. The feasibility of this technology and its superior soft error effects were demonstrated by a fully functional 4M-bit SRAM. Its radio frequency characteristics were also evaluated and it was verified that high-performance transistors and passive elements can be realized by the combination of the SOI structure and a high-resistivity substrate. Moreover, its application to a 2.5 GHz digital IC for optical communication was also demonstrated. Thus it was proven that the body-tied SOI devices with the hybrid trench isolation is suitable to realize intelligent and reliable high-speed system-on-a chip integrating various IP's.