The Evaluation of Interface Quality in HfO[sub.2] Films Probed by Time-Dependent Second-Harmonic Generation

• Published in: Materials Vol. 17; no. 14
• Main Authors: Zhang, Libo, Ye, Li, Zhao, Weiwei, Huang, Chongji, Liu, Xue, Gao, Wenshuai, Li, Tao, Min, Tai, Yang, Jinbo, Tian, Mingliang, Chen, Xuegang
• Format: Journal Article
• Language: English
• Published: MDPI AG 01.07.2024
• Subjects: Investigations; Metal oxide semiconductor field effect transistors
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma17143471

Time-dependent second-harmonic generation (TD-SHG) is an emerging sensitive and fast method to qualitatively evaluate the interface quality of the oxide/Si heterostructures, which is closely related to the interfacial electric field. Here, the TD-SHG is used to explore the interface quality of atomic layer deposited HfO[sub.2] films on Si substrates. The critical SHG parameters, such as the initial SHG signal and characteristic time constant, are compared with the fixed charge density (Q[sub.ox]) and the interface state density (D[sub.it]) extracted from the conventional electrical characterization method. It reveals that the initial SHG signal linearly decreases with the increase in Q[sub.ox], while D[sub.it] is linearly correlated to the characteristic time constant. It verifies that the TD-SHG is a sensitive and fast method, as well as simple and noncontact, for evaluating the interface quality of oxide/Si heterostructures, which may facilitate the in-line semiconductor test.