Built-in electric field influence on impurity-free vacancy disordering of InGaAs/InP quantum well structure

Abstract

Built-in electric field may enhance or retard the impurity-free vacancy disordering (IFVD) during rapid thermal annealing (RTP) by imposing a drift on charged point defects. Built-in electric field is at the interface between dielectric layer and top layer of the structure. Subsequent rapid thermal annealing leads to different intermixing results due to different field directions on InP cap layers in different doping types. Experimental results also show different influences of the built-in field on the two sublattices largely due to different charge numbers of point defects. impurity-free vacancy disordering, point defects, built-in electric field Citation:An Y P, Mei T, Teng J H, et al. Built-in electric field influence on impurity-free vacancy disordering of InGaAs/InP quantum well structure.In recent years, quantum-well-intermixing (QWI) technology including impurity free vacancy disordering [1,2], impurity-induced disordering [3,4], plasma-assisted induced disordering [5,6], laser-induced intermixing [7,8], and ion implantation induced disordering [9,10], has attracted more and more attention due to its potential application to the photonic integrated circuit. Using point defect to enhance lattice diffusion is becoming a very interesting investigation, whereas the influence of defect migration has seldom been addressed. Besides the density of point defects, the influence of built-in electric field on defect migration is also an important factor that determines the result of intermixing. Although using inductively coupled argon plasma (Ar-ICP) enhances the quantum well intermixing, Xu et al. [6] investigated the intermixing characteristic of InGaAs/InP QW under the three differently doped types (p-type, undoped, n-type) in the InP top layer with the theory of built-in electric field. They obtained that the samples with P-type InP top layer enhance the intermixing, whereas the samples with the n-type InP top layer retard the intermixing. However using the method of IFVD in this article, we have achieved the opposite result considering the effect of built-in electric field.