Laser pulse crystallization and optical properties of Si/SiO2and Si/Si3N4multilayer nano-heterostructures

Abstract

ABSTRACT Furnace annealing, cw- and pulse laser treatments were app lied for crystallization of amorphous Si nano-layers and Si nanoclusters in SiN x -Si 3 N 4 and Si-SiO 2 multilayer nanostructures. The as-deposite d and annealed structures were studied using optical methods and electron micros copy techniques. The influence of hydr ogen on crystallization and formation of Si nanoclusters was studied. Regimes for pulse laser crystallization of amorphous Si nanoclusters and nanolayers were found. This approach is applicable for the creation of dielectric films with semiconductor nanoclusters and silicon nanostructured films on non-refr actory substrates for all-silicon tandem solar cells. Keywords: Si based nanostructures, pulse laser crystallizatio n, Raman scattering, all-silicon tandem solar cells 1. INTRODUCTION Interest to dielectric films containing many periodical layers of Si nanoclusters or Si quantum wells is growing due to their perspectives of practical application [1]. For example, growing interest to crystallization of amorphous silicon films and silicon based heterostructures on non-refractory not expensive substrates is stimulated by demands of giant microelectronics. The enlargement of sizes of flat panel displays with active thin film transistor matrix can be described as “reverse Moor’s low” [2]. Dielectric films with amorphou s or crystalline Si clusters show promise as a material for optoelectronic and flash-memory applications. The most important application areas are silicon-based optoelectronic devices, non-volatile memory, and tandem solar cells based on lateral Si/SiO