Use of laser transfer processing for producing Al-Bi doped silicon electronic devices

摘要

This work explores the combination of laser transfer and laser doping in a single process, as a way to produce highly defined, heavily doped volumes on semiconductors, to produce electronic devices. The process has been realized on mono and multicrystalline silicon by means of nanosecond laser pulses. The paper studies the mechanism of the process and the requirements in terms of beam shaping, energy levels and specific constrains of the setup to get proper dopant transfer and diffusion, as well as high compositional gradient. Bismuth is selected as n-dopant, and aluminum is used as an already well known solution for laser driven heavy p-doping on silicon. The suitability of laser transfer doping for direct writing of electronic devices is assessed in terms of transfer, melting and doping capability, and compared with other State-of-the-Art laser doping processes.