Resistless pattern definition and Si selective-area deposition using an ultrathin SiO2 mask layer treated by SiHCl3

We report a selective-area deposition process using an ultrathin ${\mathrm{SiO}}_{\mathrm{2}}$ mask on which ${\mathrm{SiHCl}}_{\mathrm{3}}$ is chemisorbed. The key step of this process is resistless pattern definition utilizing electron-stimulated desorption (ESD) of Cl and Cl-containing groups from the mask surface. Compared to the previous report utilizing ESD of O from ${\mathrm{SiO}}_{\mathrm{2}},$ sensitivity to the incident electron beam has been improved by a factor exceeding ${10}^4.$ Selective-area deposition of Si on the Cl-desorbed regions is demonstrated using an ${\mathrm{Si}}_{\mathrm{2}}{\mathrm{H}}_{\mathrm{6}}$ source gas.