Nonvolatile Memory (NVM) Operation of Tunnel Field-Effect Transistor (TFET) Using Ferroelectric HfO₂ Sidewall.

In this paper, we propose a new type of nonvolatile memory (NVM) device based on a tunnel field-effect transistor (TFETs) with Ferroelectric HfO₂ sidewall. By simply utilizing the ferroelectricity of orthorhombic HfO₂ and conventional sidewall spacer technique, TFET can operate as a NVM device. The polarized charges in the ferroelectric HfO₂ spacer induced by program/erase pulse modulate the tunneling barrier between the source and channel; thus, change the threshold voltage () of TFET.

Volatile and Nonvolatile Characteristics of Asymmetric Dual-Gate Thyristor RAM with Vertical Structure.

In this paper, the volatile and nonvolatile characteristics of asymmetric dual-gate thyristor random access memory (TRAM) are investigated using the technology of a computer-aided design (TCAD) simulation. Owing to the use of two independent gates having different gate dielectric layers, volatile and nonvolatile memory functions can be realized in a single device. The first gate with a silicon oxide layer controls the one-transistor dynamic random access memory (1T-DRAM) characteristics of the device.

Self-Boosted Tunnel Field-Effect Transistor Using Nitride Charge Trapping Layer for Low Supply Voltage Operation.

Tunneling field-effect transistors (TFETs) have been studied as a candidate for low-power device due to the remarkable subthreshold characteristics. However, digital circuits composed of TFET have significantly large propagation delay compared with the conventional MOSFET circuits because of small current drivability and large gate-to-drain capacitance. In this work, the electrical characteristics of the self-boosted TFETs with nitride charge trapping layer have been studied using TCAD simulations.

Electrical Characteristics of Metal-Oxide-Semiconductor Capacitor with High-κ/Metal Gate Using Oxygen Scavenging Process.

It has been widely accepted that the mismatch of lattice constants between HfO2 and Si generates interface traps at the HfO2-Si interface, which causes the degradation of device performances. For better interface quality, very thin SiO2 film (< 2 nm) has been inserted as an interlayer (IL) between HfO2 and Si despite of the increase of EOT. In order to obtain both the better interface quality and the reduction of EOT, we used Ti metal on HfO2/IL SiO2 stack as a scavenging layer to absorb oxygens in the SiO2 and various annealing conditions were applied to optimize the thickness of the SiO2.

Clinical outcomes and considerations of the lumbar interbody fusion technique for lumbar disk disease in adolescents.

Purpose: The posterior lumbar interbody fusion (PLIF) and transforaminal lumbar interbody fusion (TLIF) techniques are commonly used surgical methods for wide indications such as degeneration or trauma. Although they are rarely required for lumbar disk disease in younger patients, there are a few children and adolescents who are indicated for PLIF or TLIF for other reasons, such as congenital severe stenosis with or without lumbar instability that requires wide decompression or severe bony spur that need to be removed. In such cases, different pathophysiology and outcomes are expected compared with adult patients.

Split-gate-structure 1T DRAM for retention characteristic improvement.

As the feature size of the conventional 1T-1C DRAM scales down, difficulties of the fabrication process are increasing and it is becoming harder to keep a constant capacitance value for data storage. Capacitor-less 1T DRAM is a promising candidate for the substitution of the conventional 1T-1C DRAM, but its poor retention time is one of the critical issues in its commercialization. In the selection of a bias condition for 1T DRAM, however, it is impossible to choose a gate bias condition that is suitable for both the "1" and "0" hold state data.