Photoelectric threshold of silicon wafer surfaces implanted with H, Si and Ar ions

Abstract

The effect of ion implantation on the photoemission spectral yield for native oxide-covered Si(100) wafer surfaces has been studied. Three types of H, Si and Ar atoms were employed for the ion implantation. For one sample the yield curve was measured successively first at 25• C, next after heating to 340• C, and subsequently after cooling to 40 • C. All implanted samples showed the photoemission in the spectral yield with a much enhanced intensity compared to a nonimplanted sample, moreover, more strongly at 340• C than at 25 and 40• C. The analysis of the yield curve showed two distinct photothresholds of φ 1 and φ 2 , which can be attributed to the interface states at the SiO 2 /Si interface and the silicon bulk, respectively, and the creation of a localized emitting center ascribed to E center ( Si ·). Both thresholds for the implanted samples were reduced about 0.3-0.5 eV compared to those for the nonimplanted sample. The localized center appeared at the photon energy of 5.66 eV (25 and 40• C) and 5.76 eV (340• C), and the amount of the centers created at 340• C was much greater than that at 25 and 40 • C. Interestingly, the amount of the E centers at 25• C for the H implanted sample tended to decrease with an increase in the concentration of implanted H atoms.

Electron Transfer through a Natural Oxide Layer on Real Metal Surfaces Occurring during Sliding with Polytetrafluoroethylene: Dependence on Heat of Formation of Metal Oxides

“…The electron or charge transfer at real metal surfaces has also been of great importance in fields such as tribology [4,5] and triboelectric energy production methods [6]. In order to characterize real surfaces, we assessed electron emission (EE) occurring during three main processes of friction, sliding metal surfaces with polymer riders, thermal assistance, and photo or optical stimulation, and examined the EE characteristics of real surfaces of metals, semiconductors, and other materials remaining in ambient environments [7][8][9][10][11]. Furthermore, we reported the relationships between the EE from various metal surfaces and the adhesion and chemical reactions [12][13][14].…”