Atomic Layer Deposition of Al‐doped ZnO Films Using Aluminum Isopropoxide as the Al Precursor

Abstract

Abstract Al‐doped ZnO (AZO) films are deposited at 200°C by atomic layer deposition (ALD) on borosilicate glass and Si(001) substrates using diethylzinc (DEZ) and aluminum isopropoxide (AIP) as the Zn and Al precursors, respectively. The effect of the Zn/Al ALD cycle ratio and the AIP source temperature on the Al dopant concentration and resistivity of AZO films is carefully investigated. By changing the AIP temperature from 115°C to 135°C, at the optimal Zn/Al cycle ratio of 19:1, the Al dopant concentration ([Al]/([Al] + [Zn])) in AZO films varies from 0.15 at.‐% to 2.32 at.‐%. The 60 nm thick AZO films deposited at an AIP temperature of 120°C show the lowest resistivity of 9.4 × 10 −4 Ω cm, with better optical transparency.