Atomic Layer Deposition of SrS and BaS Thin Films\nUsing Cyclopentadienyl Precursors

Abstract

SrS and BaS thin films were grown on glass substrates using an atomic layer deposition\n(ALD) technique and (C₅<i>ⁱ</i>Pr₃H₂)₂Sr(THF) (<b>1</b>), (C₅Me₅)₂Sr(THF)<i>_x</i> (<b>2</b>), (C₅Me₅)₂Ba(THF)<i>_x</i> (<b>3</b>),\nand H₂S as precursors. Deposition temperatures were 120−460, 155−400, and 180−400 °C\nwith <b>1</b>, <b>2</b>, and <b>3</b>, respectively. Growth rate of the films varied between 0.6 and 3.0 Å/cycle\nand all the films were polycrystalline as deposited. The amount of C, H, and O residues was\nfound to be 0.1−0.6 at. % in the films grown at 300 °C as determined by time-of-flight elastic\nrecoil detection analysis (TOF-ERDA). Growth mechanisms for the films grown at different\ntemperatures were also proposed. Crystal structures of <b>2</b> and <b>3</b> were determined.