Electrical surface conductivity in quartz induced by ion implantation Available to Purchase

Quartz was implanted with titanium ions at high doses (up to 3.3×10¹⁷ cm⁻²). At low energy (40 keV), a highly conductive layer was formed near the surface. The measured sheet resistance was less than 100 Ω/⧠. The implantation‐induced changes in quartz were characterized using various methods such as cross‐sectional transmission electron microscopy, Rutherford backscattering spectrometry, and x‐ray photoelectron spectroscopy (XPS). As a result of ion implantation, SiO₂ was dissociated. Metallic titanium and new chemical compounds between Si, O, and Ti were observed by XPS. However, no conductivity was observed with other metallic ions, such as Fe and Cu, which are known not to react chemically with SiO₂. This suggests a correlation between the induced surface conductivity and the chemical reactivity of the implanted species with SiO₂. The ion beam synthesis of such a near‐surface conductive layer was then applied during the fabrication of miniaturized pressure sensors based on piezoelectric quartz. This technique is proposed to replace the more conventional approach, i.e., deposition of a thin metallic layer, and to resolve problems related to the hermetic seal made by field‐assisted bonding between glass and quartz plate.