Novel Vertical SOI-Based 1T-DRAM With Trench Body Structure

Sun

IEEE J. Electron Devices Soc.

et al. 2019

Self Cite

In this paper, we propose a novel structure of doping-less 1T-DRAM with raised body and Schottky contact to source/drain regions which uses thermionic emission to generate electrons and holes. As the device is free from physical doping, the problems associated with random dopant fluctuations will be eliminated in the proposed doping-less topology. Our simulation results show that a programming window of 28.7 μA/μm at a gate length of 10 nm with the retention time of 466 ms at 27 • C and 79 ms at 85 • C can be achieved with the proposed doping-less 1T-DRAM, which is much better than a conventional charge-plasma based doping-less 1T DRAM.

Section: Introductionmentioning

confidence: 99%

Raised Body Doping-Less 1T-DRAM With Source/Drain Schottky Contact

Sun

IEEE J. Electron Devices Soc.

et al. 2019

Self Cite

ACS Appl. Mater. Interfaces

“…Silicon nitride (SiN x ) thin films are still actively investigated for next-generation semiconductor devices as a gate spacer for memory and logic devices and charge storage layer for nonvolatile memory devices. − The conventional deposition of SiN x thin films such as in low-pressure chemical vapor deposition (LPCVD) requires high temperatures (>600 °C), which is not compatible with the deposition of the metal layer of the semiconductor devices. − Moreover, applications such as amorphous oxide semiconductor (AOS) low-temperature (<400 °C) SiN x deposition as a phase transition can occur at higher temperatures (400–500 °C). − Besides the issues involved in lowering the process temperature, there are other process related requirements such as accurate thickness control, high conformality, and stability during the integration of semiconductor devices. − Therefore, the plasma-enhanced atomic layer deposition (PEALD) process that could lower the process temperature while maintaining the advantages of ALD is a promising technology among various SiN x thin film deposition methods. − …”

Section: Introductionmentioning

confidence: 99%

Plasma Enhanced Atomic Layer Deposition of Silicon Nitride for Two Different Aminosilane Precursors Using Very High Frequency (162 MHz) Plasma Source

Kim

Choi

et al. 2023

Plasma enhanced atomic layer deposition (PEALD) of silicon nitride (SiN x ) using very high frequency (VHF, 162 MHz) plasma source was investigated at the process temperatures of 100, 200, and 300 °C. Two aminosilane precursors having different numbers of amino ligands, bis(tert-butylamino)silane (BTBAS) and di(sec-butylamino)silane (DSBAS), were used as Si precursors. A comparative study was also conducted to verify the effect of the number of amino ligands on the properties of SiN x film. At all process temperatures, DSBAS, having one amino ligand, performed better than BTBAS in various aspects. SiN x films deposited using DSBAS had lower surface roughness, higher film density, lower wet etch rate, improved electrical characteristics, and higher growth rate than those deposited using BTBAS. With the combination of a VHF plasma source and DSBAS with one amino ligand, the SiN x films grown at 300 °C exhibited low wet etch rates (≤2 nm/min) in a dilute HF solution (100:1 of deionized water:HF) as well as low C content below the XPS detection limit. Also, excellent step coverage close to 100% on high aspect ratio (30:1) trench structures was obtained by using VHF plasma, which could provide sufficient flux of plasma species inside the trenches in conjunction with DSBAS having fewer amino ligands than BTBAS.

“…However, planar 1T-DRAM still exhibits poor retention time. Therefore, various structures and methods for improving the memory characteristic have been investigated [6][7][8][9][10][11][12][13][14][15][16][17].…”

Section: Introductionmentioning

confidence: 99%

Design of a Capacitorless DRAM Based on a Polycrystalline-Silicon Dual-Gate MOSFET with a Fin-Shaped Structure

Lee

Park

et al. 2022

Nanomaterials

In this study, a capacitorless one-transistor dynamic random-access memory (1T-DRAM) cell based on a polycrystalline silicon dual-gate metal-oxide-semiconductor field-effect transistor with a fin-shaped structure was optimized and analyzed using technology computer-aided design simulation. The proposed 1T-DRAM demonstrated improved memory characteristics owing to the adoption of the fin-shaped structure on the side of gate 2. This was because the holes generated during the program operation were collected on the side of gate 2, allowing an expansion of the area where the holes were stored using the fin-shaped structure. Therefore, compared with other previously reported 1T-DRAM structures, the fin-shaped structure has a relatively high retention time due to the increased hole storage area. The proposed 1T-DRAM cell exhibited a sensing margin of 2.51 μA/μm and retention time of 598 ms at T = 358 K. The proposed 1T-DRAM has high retention time and chip density, so there is a possibility that it will replace DRAM installed in various applications such as PCs, mobile phones, and servers in the future.