Kang-yoon Lee

A New Capacitorless 1T DRAM Cell: Surrounding Gate MOSFET With Vertical Channel (SGVC Cell)

We propose a surrounding gate MOSFET with vertical channel (SGVC cell) as a 1T DRAM cell. To confirm the memory operation of the SGVC cell, we simulated its memory effect and fabricated the highly scalable SGVC cell. According to simulation and measurement results, the SGVC cell can operate as a 1T DRAM having a sufficiently large sensing margin. Also, due to its vertical channel structure and common source architecture, it can readily be made into a 4F2 cell array

Study on reliability of metal fuse for sub-100nm technology

Tungsten bit line fuse has been used for years in repair application but it fails during BOC (board on chip) package PCT (pressure cooker test) because of its weakness to corrosion. We searched for new material against corrosion, and metal-1 aluminum fuse was set up. Although there is no failure in PCT, we have found a fatal failure in IMD (inter-metal dielectric) crack during THB (temperature humidity bias test). We developed SiN full passivation scheme to resolve the failure then there is no failure until THB 1000 hours. Finally we set up metal-1 aluminum fuse process for sub-100 nm technology

A CMOS dual-band fractional-n synthesizer with reference doubler and compensated charge pump

A fully integrated dual-band frequency synthesizer in 0.35 /spl mu/m CMOS technology achieves a phase noise of -141 dBc/Hz at 1.25 MHz offset in the PCS band with a reference frequency doubler. Fractional spurs are reduced by 8.6 dB at 50 kHz offset with a replica compensated charge pump.

A 32-bank 1 Gb self-strobing synchronous DRAM with 1 GByte/s bandwidth

This paper describes a 32-bank 1 Gb DRAM achieving 1 Gbyte/s (500 Mb/s/DQ pin) data bandwidth and the access time from RAS of 31 ns at V/sub cc/=2.0 V and 25/spl deg/C. The chip employs (1) a merged multibank architecture to minimize die area; (2) an extended small swing read operation and a single I/O line driving write scheme to reduce power consumption; (3) a self-strobing I/O schemes to achieve high bandwidth with low power dissipation; and (4) a block redundancy scheme with increased flexibility. The nonstitched chip with an area of 652 mm/sup 2/ has been fabricated using 0.16 /spl mu/m four-poly, four-metal CMOS process technology.

Comparison frequency doubling and charge pump matching techniques for dual-band /spl Delta//spl Sigma/ fractional-N frequency synthesizer

The frequency synthesizer with two LC-VCOs is fully integrated in a 0.35-/spl mu/m CMOS technology. In supporting dual bands, all building blocks except VCOs are shared. A current compensation scheme using a replica charge pump improves the linearity of the frequency synthesizer and, thus, suppresses spurious tones. To reduce the quantization noise from a /spl Delta//spl Sigma/ modulator and the noise from the building blocks except the VCO, the proposed architecture uses a frequency doubler with a noise-insensitive duty-cycle correction circuit (DCC) in the reference clock path. Power consumption is 37.8 mW with a 2.7-V supply. The proposed frequency synthesizer supports 10-kHz channel spacing with the measured phase noise of -114 dBc/Hz and -141 dBc/Hz at 100-kHz and 1.25-MHz offsets, respectively, in the PCS band. The fractional spurious tone at 10-kHz offset is under -54 dBc.

Modeling of cumulative thermo-mechanical stress (CTMS) produced by the shallow trench isolation process for 1 Gb DRAM and beyond

The defects induced by the thermo-mechanical stress in the device fabrication process are correlated with device characteristics of 1 Gb DRAM. To identify the defect formation in the thermal process, we modeled the cumulative thermo-mechanical stress (CTMS) throughout the shallow trench isolation (STI) integrated DRAM process, and performed computer simulation using ABAQUS. The defect-free stress level was extracted from the relationship between the cumulative shear stress and electrical device characteristics, and then applied to optimizing thermal annealing process to obtain the defect-free process condition for the fabrication of 1 Gb DRAM and beyond.

A 32-bank 1 Gb DRAM with 1 GB/s bandwidth

This 32-bank 1 Gb DRAM features: (1) a merged bank architecture (MBA) that results in only 3% die area penalty for 32-bank operation; (2) a source-synchronous I/O interface (SSI) that achieves 1 GB/s bandwidth with low power consumption; (3) flexible block redundancy that allows freedom of repair to anywhere within each half-Gb array; and (4) extended small swing read and single-I/O line driving write which result in 30% power reduction. The DRAM chip is implemented in a 0.16 /spl mu/m twin-well CMOS process.

A Novel Low Leakage Current VPT(Vertical Pillar Transistor) Integration for 4F2 DRAM Cell Array with sub 40 nm Technology

for 4F2 DRAM Cell Array with sub 40 nm Technology Jae-Man Yoon, Kangyoon Lee, Seung-Bae Park, Seong-Goo Kim, Hyoung-Won Seo, Young-Woong Son, Bong-Soo Kim, Hyun-Woo Chung, Choong-Ho Lee*, Won-Sok Lee* *, Dong-Chan Kim* * *, Donggun Park*, Wonshik Lee and Byung-Il Ryu ATD Team, Device Research Team*, CAEP*, PD Team***, Semiconductor R&D Division, Samsung Electronics Co., San #24, Nongseo-Dong, Kiheung-Gu, Yongin-City, Kyunggi-Do, 449-711, Korea Tel) 82-31-209-4741, Fax) 82-31-209-3274, E-mail)

Robust Metal/AHO/HSG-Cylinder Capacitor Technology Using Diagonal Cell Array Scheme and Double Mold Oxide

In this paper the novel robust Hemispherical Grain (HSG)-merged Al2O3/HfO2 (AHO) capacitor with diagonal cell array scheme and double mold oxide (DMO) is introduced. The capacitor process with diagonal cell array scheme and double mold oxide can maximize storage node (SN) height up to 2.0 µm in 0.11 µm dynamic random access memory (DRAM) technology by enlarging the bottom size of SN. Also we developed the HSG-merged AHO capacitor for the first time in mass production. The HSG-merged AHO capacitor technique exhibited a capacitance enhancement by 24% without any significant decrease in breakdown voltage compared to Al2O3 (ALO) capacitor.