Du-Eung Kim

A 90nm 1.8V 512Mb Diode-Switch PRAM with 266MB/s Read Throughput

A 512Mb diode-switch PRAM is developed in a 90nm CMOS technology. A core configuration, read/write circuit techniques, and a charge-pump system for the diode-switch PRAM are described. Through these schemes, the PRAM achieves read throughput of 266MB/S and maximum write throughput of 4.64MB/S with a 1.8V supply.

A 0.1-

A 256-Mb phase-change random access memory has been developed, featuring 66-MHz synchronous burst-read operation. Using a charge pump system, write performance was characterized at a low supply voltage of 1.8 V. Measured initial read access time and burst-read access time are 62 and 10 ns, respectively. The write throughput was 0.5 MB/s with internal times2 write and can be increased to ~2.67 MB/s with times16 write. Endurance and retention characteristics are measured to be 107 cycles and ten years at 99 degC

\mu{\hbox {m}}

A non-volatile 64 Mb phase-transition RAM is developed by fully integrating a chalcogenide alloy GST (Ge/sub 2/Sb/sub 2/Te/sub 5/) into 0.18 /spl mu/m CMOS technology. This alloy is programmed by resistive heating. To optimize SET/RESET distribution, a 512 kb sub-core architecture, featuring meshed ground line, is proposed. Random read access and write access for SET/RESET are 60 ns, 120 ns and 50 ns, respectively, at 3.0 and 30/spl deg/C.

1.8-V 256-Mb Phase-Change Random Access Memory (PRAM) With 66-MHz Synchronous Burst-Read Operation

A 1.8 V 64 Mb phase-change RAM with improved write performance is fabricated in a 0.12 /spl mu/m CMOS technology. The improvement of RESET and SET distributions is based on cell current regulation and multiple step-down pulse generators. The read access time and SET-write time are 68 ns and 180 ns respectively.

A 0.18 /spl mu/m 3.0 V 64 Mb non-volatile phase-transition random-access memory (PRAM)

The booster plate in NAND flash memory cells gives numerous advantages: the reduction of program, erase and pass voltages, zero program disturbance and increased cell current. At the same time, it is simple to integrate the technology to the conventional fabrication processes. It is expected that the booster plate technology will become one of the key technologies for achieving high density memories such as 256 Mbit and 1 Gbit NAND flash.

Enhanced write performance of a 64 Mb phase-change random access memory

A 256Mb PRAM featuring synchronous burst read operation is developed. Using a charge-pump system, write performance is characterized at 1.8V supply. Measured initial read access time and burst-read access time are 62ns and 10ns, respectively. The maximum write throughput is 3.3MB/S

A novel booster plate technology in high density NAND flash memories for voltage scaling-down and zero program disturbance

The high speed NAND flash memory cell with a read access time of 80 ns has been demonstrated. In the process integration of the high speed cell, complementary polycide bit lines with the ground selection scheme, self-aligned field through implantation, and metal source line have been introduced. The reliable high speed NAND cell operation has been achieved by enhanced sensing voltage swing, increased cell current and reduced bit line loading.