First Realization of ALD Based Sn-Doped InGaZnO with Reliability Enhancements for Monolithic 3D Integratation

We report the first realization and characterization of Sn-doped InGaZnO (IGZTO) FETs using atomic layer deposition (ALD) for 3D integration. Thermal stability and composition/thickness dependence are systematically explored. ALD IGZTO FETs show high thermal stability up to 400°C, and exhibit key trade-offs among mobility, threshold voltage (V<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</inf>), and V<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</inf> shift (Δ V<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</inf>) under bias stress. Compared to ALD IGZO FETs, IGZTO FETs offer higher mobility and enhanced reliability without reducing V<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</inf>, attributed to Sn doping that improves percolation pathways through 5s orbital overlap with In while suppressing excessive oxygen vacancy (V<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</inf>). These findings provide insights into novel ALD OS channel materials to realize high-performance OS FETs in monolithic 3D (M3D) integration.