Abstract: A novel energy beam induced layer disordering (EBILD) process is used to (a) locally melt in a scanned pattern regions of a solid state semiconductor heterostructure to produce an alloy of intermediate composition having different optical properties and/or (b) incorporating significantly large amounts of an impurity, present in an encapsulation surface layer of a solid state semiconductor heterostructure, into regions of the heterostructure via absorption of the impurity into liquid alloy melt to form regions having different optical and/or electrical properties and (c) thereafter optionally applying IID to enlarge or extend the disordered/as-grown boundaries of the initially melted region. As a direct write analogue to surface initiated impurity induced disordering (IID), EBILD is a flexible and viable process with high importance for continuous reproducibility and high yield in the fabrication of optoelectronic devices and thin film electronic and optoelectronic circuitry.