Prototype of Phase-Change Channel Transistor for Both Nonvolatile Memory and Current Control

Abstract

We prototyped phase-change (PC) channel transistors and demonstrated two functions of nonvolatile memory and channel current control. We have developed prototype transistors that use a PC channel instead of a silicon channel. The PC material of a Ge <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Sb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Te <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> thin film with a thickness of 50 nm was used. We demonstrated a memory function whereby we achieved a reversible change between the crystalline and amorphous phases by applying a source-drain (SD) voltage for Joule heating. In the experiment, the applied voltages for PC between amorphous and crystalline phases were from 5 to 8 V. Control of the channel current was realized by applying a gate bias. The SD current was suppressed to less than 1/20 of that at a gate bias of -3 V by applying a gate bias of 0-3 V