Improvement of Surface Roughness in SiO ₂ Thin Films via Deuterium Annealing at 300 °C

Recently, deuterium annealing at a reduced temperature range of 300 °C has been proposed to enhance SiO<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> gate dielectrics and the Si/SiO<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> interface, thereby improving device reliability. As a further investigation into deuterium annealing, for the first time this study compared deuterium absorption characteristics with various SiO<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> dielectrics formed by wet oxidation, dry oxidation, low-pressure chemical vapor deposition (LPCVD), and plasma-enhanced chemical vapor deposition (PECVD). Deuterium annealing can also be used to reduce the roughness and improve the uniformity of SiO<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> dielectric films. Surface roughness of various samples was measured and quantitatively compared using atomic force microscopy (AFM) after deuterium annealing.