Ion-induced electron emission (IIEE) from undoped and B-doped diamond films induced by 1–10 KeV H + and Ar +

Abstract

A newly developed experimental system enables measurements of IIEE at a very low ion flux (10 5 ions/s cm 2) avoiding the fast emission degradation caused by high ion fluxes (usually applied 10 10–10 13 ions/s cm 2). The method overcomes the difficulty of measurement of reliable ion-induced secondary electron emission (IIEE) yield, associated with fast degradation of the IIEE yield. We report on the investigation of the IIEE from hydrogenated undoped and B-doped diamond films as a function of (i) moderate heating in vacuum prior to the measurements, (ii) H + and Ar + energy in the range of 1–10 KeV, and (iii) film thickness and microstructure. An IIEE yield ( γ) enhancement was typically detected when the films were heated to 300 °C in vacuum. In the B-doped diamond film heated to 300 °C, γ rose nearly linearly from ∼ 20 to ∼ 100 electrons/ion, for 1 to 10 KeV Ar + ions, respectively. The values of γ obtained with H + showed a more moderate, nonlinear increase from ∼ 8 electrons/ion at 1 KeV up to ∼ 90 electrons/ion at 10 KeV. In heated undoped diamond films of different thicknesses the measured values of γ were similar for all the studied films and somewhat lower than in B-doped film: from ∼ 10–16 to 60–70 electrons per 1 to10 KeV Ar +, respectively, and from 14–26 to 50–60 electrons per 1 to10 KeV H +, respectively. The experimental results were interpreted using TRIM calculations.