A nonalloy Ohmic electrode is formed on a hydrothermally grown n-type ZnO substrate by KrF excimer laser irradiation and metal deposition without any impurity doping. Laser irradiation changes the ZnO surface layer to a Zn-rich one with lower sheet resistance than the bulk. The Zn-rich premetallized layer (ZnOx layer, x=0–1) exhibits n+-type conduction, which enables current conduction into the ZnO substrate with Ohmic characteristics. An In/ZnOx contact fabricated by single-pulse laser irradiation with 0.3 J/cm2 on the ZnO substrate has a contact resistance of 7×10−1 Ω cm2. A postheat treatment for 5 min at 300 °C increases the sheet resistance in the premetallized layer, which causes an increase of the contact resistance of the fabricated contact.
A two-step doping method consisting of the deposition of dopant films and the incorporation of dopant atoms using excimer laser has been studied in boron doping of silicon. These processes are carried out in the same chamber successively. Sheet resistance can be varied widely by changing both the number and the energy density of the depositing laser pulses. In this method, dopants diffuse in the melted silicon from a fixed total dopant source with a simple Gaussian distribution when the number of melting pulses is small. The diffusion coefficient of B in liquid Si is determined experimentally.
A dry surface passivation of GaAs using the combination of H2S gas with an ArF excimer laser was examined. Native oxides at the surface were etched away by laser irradiation in vacuum. By subsequent laser irradiation in a H2S gas ambient, the surface was covered with sulfur atoms. The dry passivation technique in this study is comparable to the wet passivation process using (NH4)2Sx treatment in terms of the sulfur coverage ratio.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.