Carrier properties of B atomic-layer-doped Si films grown by ECR Ar plasma-enhanced CVD without substrate heating. Issue 1 (31st December 2017)

• Record Type: Journal Article
• Authors: Sakuraba, Masao; Sugawara, Katsutoshi; Nosaka, Takayuki; Akima, Hisanao; Sato, Shigeo
• Is Part Of: Science and technology of advanced materials. Volume 18:Issue 1(2017)
• Page Start: 294
• Page End: 306
• Publication Date: 2017-12-31
• Subjects: Epitaxial growth -- atomic-layer doping -- plasma-enhanced chemical-vapor deposition -- argon -- silicon -- boron -- carrier mobility -- Hall effect; 40 Optical, magnetic and electronic device materials -- 105 Low-Dimension (1D/2D) materials -- 201 Electronics / Semiconductor / TCOs -- 212 Surface and interfaces -- 302 Crystallization / Heat treatment / Crystal growth -- 305 Plasma / Laser processing -- 306 Thin film / Coatings; Materials -- Technological innovations -- Periodicals; 620.112
• DOI: 10.1080/14686996.2017.1312520
• Languages: English
• ISSNs: 1468-6996

Abstract

Abstract: The atomic-layer (AL) doping technique in epitaxy has attracted attention as a low-resistive ultrathin semiconductor film as well as a two-dimensional (2-D) carrier transport system. In this paper, we report carrier properties for B AL-doped Si films with suppressed thermal diffusion. B AL-doped Si films were formed on Si(100) by B AL formation followed by Si cap layer deposition in low-energy Ar plasma-enhanced chemical-vapor deposition without substrate heating. After fabrication of Hall-effect devices with the B AL-doped Si films on unstrained and 0.8%-tensile-strained Si(100)-on-insulator substrates (maximum process temperature 350°C), carrier properties were electrically measured at room temperature. Typically for the initial B amount of 2 × 10 14 cm −2 and 7 × 10 14 cm −2, B concentration depth profiles showed a clear decay slope as steep as 1.3 nm/decade. Dominant carrier was a hole and the maximum sheet carrier densities as high as 4 × 10 13 cm −2 and 2 × 10 13 cm −2 (electrical activity ratio of about 7% and 3.5%) were measured respectively for the unstrained and 0.8%-tensile-strained Si with Hall mobility around 10–13 cm 2 V −1 s −1 . Moreover, mobility degradation was not observed even when sheet carrier density was increased by heat treatment at 500–700 °C. There is a possibility that the local carrier (ionized B atom) concentration around the B AL in Si reaches around 10 21 cm −3 and 2-D impurity-band formation with strong Coulomb interaction is expected. The behavior of carrier properties for heat treatment at 500–700 °C implies that thermal diffusion causes broadening of the B AL in Si and decrease of local B concentration. Abstract :