Plasma-Enhanced Atomic Layer Deposition of p-type Nickel Oxide Thin Films Using an Amidinate Precursor

High Resolution Image Download MS PowerPoint Slide High-quality thin films of oxide semiconductors are desirable for many emerging applications in electronic devices. However, the lack of a stable native p -type oxide semiconductor has hindered the full potential of integrated oxide technologies. Nickel oxide (NiO x ) has emerged as a promising native p -type oxide semiconductor. Yet, achieving dense, low-defect p -type NiO x thin films by CMOS-compatible processes remains a significant challenge. In this study, we present an amidinate-based plasma-enhanced atomic layer deposition (PE-ALD) technique enabling oxygen-rich p -type polycrystalline NiO x thin films. We demonstrate monolayer deposition at platen temperatures between 175 and 225 °C, with carbon- and nitrogen-containing species contamination below 0.5%. Moreover, a CMOS-compatible 60-min capacitively coupled O 2 plasma post-deposition treatment activates hole conduction in the 10 nm NiO x films, as confirmed by Hall-effect measurements of van der Pauw metrology structures. This approach yields a hole mobility of 29.4 cm 2 /(V s), carrier concentration of 8.0 × 10 15 cm −3, and sheet resistance of 26.5 MΩ/□, owing to minimal contamination, effective oxygen enrichment, and suppression of surface hydroxyl groups. These findings highlight (i) the advantages of PE-ALD as a precise, CMOS-compatible deposition method for oxide semiconductors, which is scalable and reproducible, (ii) the importance of oxygen enrichment to NiO x in achieving p -type conduction, and (iii) the potential of NiO x as a native p -type oxide semiconductor with viable hole mobility for back-end-of-line CMOS-compatible integration.