Localized intermixing of AlAs and GaAs layers for lithographic control of the lateral oxidation of AlAs

We present a method to achieve lithographic control of the lateral oxidation of AlAs layers. The technique uses impurity induced layer disordering (IILD) in buried, heavily Si-doped layers to introduce Ga atoms into the AlAs layers to be oxidized. By selectively patterning the wafer surface and combining point defect generation mechanisms from the uncapped surface and in the highly Si-doped layers, this intermixing may be localized. Because lateral oxidation rates are heavily dependent on Al mole-fraction, lateral oxidation stop layers can thus be formed. Results are discussed for several types of capping conditions, and SUPREM simulations of the two-dimensional disordering process are presented.