Doping of SiC by Implantation of Boron and Aluminum

Abstract

Experimental studies on aluminum (Al) and boron (B) implantation in 4H/6H SiC are reported; the implantation is conducted at room temperature or elevated temperatures (500 to 700 °C). Both Al and B act as “shallow” acceptors in SiC. The ionization energy of these acceptors, the hole mobility and the compensation in the implanted layers are obtained from Hall effect investigations. The degree of electrical activity of implanted Al/B atoms is determined as a function of the annealing temperature. Energetically deep centers introduced by the Al+/B+ implantation are investigated. The redistribution of implanted Al/B atoms subsequent to anneals and extended lattice defects are monitored. The generation of the B‐related D‐center is studied by coimplantation of Si/B and C/B, respectively.

1950°C Post Implantation Annealing of Al+Implanted 4H-SiC: Relevance of the Annealing Time

“…Last but not least, a reason for preferring Al to B, is that Al is almost immobile during post implantation annealing while B not at all. 22 This works is a study on the relevance of the annealing time during the electrical activation of Al implanted in 4H-SiC at 1950…”

Comparison of Solid-State Microwave Annealing with Conventional Furnace Annealing of Ion-Implanted SiC

“…In the case of SiC, post-implantation annealing needs to be performed at temperatures >1,500°C to achieve reasonable implant activation. 7,8 These anneals are conventionally performed in resistively or inductively heated ceramic furnaces. 7,8 However, there are several critical problems with conventional anneals.…”

Spatial Localization of Carrier Traps in 4H-SiC MOSFET Devices Using Thermally Stimulated Current

“…[11][12][13][14] Studies of p-type 6H-SiC MOS capacitors by Lysenko et al 11 and Ó lafsson et al 12 showed two main peaks in the TSC spectra, located at approximately 50 K and 70 K. The origin of the former peak was attributed to interface states, whereas the latter was concluded to be due to Al acceptors (E A = 160 meV to 230 meV). [15][16][17] On n-type 4H-SiC, Rudenko et al observed TSC peaks near 40 K, 90 K, and 150 K. 13,14 The 40-K peak was attributed to N donor ionization, and the other two peaks were due to the presence of interface states near the conduction band. In addition, Fang et al have performed TSC characterization of 4H-SiC substrates, identifying Al, B, and V defect levels at 0.22 eV, 0.28 eV, and 0.91 eV, respectively.…”