Detailed Analysis and Precise Modeling of Multiple-Energy Al Implantations Through \hbox Layers Into 4H-SiC

• Published in: IEEE transactions on electron devices Vol. 55; no. 8; pp. 1997 - 2003
• Main Authors: Mochizuki, Kazuhiro, Someya, Tomoyuki, Takahama, Takashi, Onose, Hidekatsu, Yokoyama, Natsuki
• Format: Journal Article
• Language: English
• Published: IEEE 01.08.2008
• Subjects: Aluminum; Analytical models; Doping; ion implantation; Ions; Monte Carlo methods; power semiconductor devices; Silicon; Silicon carbide; silicon compounds; simulation; Surface treatment
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2008.926631

This paper presents a detailed analysis and precise modeling of multiple-energy Al implantations necessary for boxlike profiles in the p + -region of 4H-SiC power devices. To demonstrate the balance between "scatter-in channeling" and "amorphization-suppressed channeling," a thin-surface SiO 2 layer is formed on 4H-SiC substrates misoriented by 8deg from (0001) toward [112 macr0]. Experimental, as well as Monte-Carlo-simulated, as-implanted concentration profiles of Al normally incident to the surface suggest that the least ion channeling is realized for implantations without SiO 2 in a decreasing energy order. To understand this mechanism, concentration profiles of Al implantations at a single energy with and without SiO 2 are modeled using the dual-Pearson approach. Based on the developed model, the Al ion channeling in 4H-SiC is discussed in terms of effects of surface SiO 2 layers and the sequence of multiple-energy implantations.