Enhanced AlScN/GaN Heterostructures Grown with a Novel Precursor by Metal–Organic Chemical Vapor Deposition. Issue 2 (1st November 2022)

• Record Type: Journal Article
• Authors: Streicher, Isabel; Leone, Stefano; Kirste, Lutz; Manz, Christian; Straňák, Patrik; Prescher, Mario; Waltereit, Patrick; Mikulla, Michael; Quay, Rüdiger; Ambacher, Oliver
• Is Part Of: Physica status solidi. Volume 17:Issue 2(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-11-01
• Subjects: AlScN -- high-electron-mobility transistors -- metal–organic chemical vapor deposition -- ScAlN -- vapor pressure; Solid state physics -- Periodicals; 530.4105
• DOI: 10.1002/pssr.202200387
• Languages: English
• ISSNs: 1862-6254

Abstract

Abstract : Growth of AlScN high‐electron‐mobility transistor (HEMT) structures by metal–organic chemical vapor deposition (MOCVD) is challenging due to the low vapor pressure of the conventionally used precursor tris‐cyclopentadienyl‐scandium (Cp3 Sc). It is shown that the electrical and structural characteristics of the AlScN/GaN heterostructure improve significantly by using bis‐methylcyclopentadienyl‐scandiumchloride ((MCp)2 ScCl), which has a higher vapor pressure and allows for an increased molar flow and thus higher growth rate (GR). AlScN/GaN HEMT heterostructures with superior electrical characteristics deposited at different barrier growth temperatures are presented. The sheet resistance R sh of 172 Ω sq −1 obtained at 900 °C barrier growth temperature is among the lowest reported so far for AlScN/GaN HEMT structures. The sheet charge carrier density n s is 3.23 × 10 13 cm − 2 and the electron mobility μ is 1124 cm 2 Vs −1 . Abstract : AlScN high‐electron‐mobility transistor structures are grown by metal–organic chemical vapor deposition with increased barrier growth rate using a novel precursor. This results in a decreased thermal budget, reduced interface diffusion, and excellent electrical characteristics such as high sheet charge carrier density and electron mobility and the lowest sheet resistance reported so far in literature for passivated AlScN/GaN heterostructures.