Ultra-low Leakage IGZO-TFTs with Raised Source/Drain for V_t > 0 V and I_on > 30 µA/µm

Abstract

To address the requirements of 2T0C 3D-DRAMs, raised source/drain architecture for front-gated amorphous IGZO-TFTs is demonstrated. Record I <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</inf> (> 30 µA/µm) with V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t</inf> of +0.3 V is achieved with scaled a-IGZO channel and CAAC-IGZO raised contacts along with the oxygen tunnel module. The role of raised contacts on device performance is systematically investigated. We also report ultra-low I <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</inf> ~ 4×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-19</sup> A/µm for raised contact devices.