NOVELTY - A laser diode is formed by providing a laser diode material structure including a surface region; depositing a multilayer dielectric stack overlying surface region and comprising alternating first and second dielectric layers; selectively removing a portion of multilayer dielectric stack to form a dielectric mask structure; selectively removing a portion of first dielectric layers to form undercut region; depositing passivation layer(s) (1102) overlying dielectric mask structure; selectively removing dielectric mask structure; and forming a contact structure overlying a top surface region.    USE - Method for forming a laser diode. Uses include but are not limited to optical devices, lasers, LEDs (e.g. red, green, blue), solar cells, photoelectrochemical water splitting and hydrogen generation devices, photodetectors, integrated circuits, or transistors.    ADVANTAGE - The method allows the multilayer mask structure to eliminate the use of a photoresist material to expose a top surface region, and the top surface region allows for a contact structure to form for the optical device structure. Also, the multilayer mask structure provides for a thick dielectric mask without incurring stress on the optical device structure.    DETAILED DESCRIPTION - Formation of a laser diode comprises:    (A) providing a laser diode material structure including an under clad layer, an upper clad layer having a surface region, and an active layer sandwiched between the under clad layer and the upper clad layer;    (B) depositing a multilayer dielectric stack overlying the surface region and comprising alternating layers of at least a first dielectric layer and a second dielectric layer;    (C) selectively removing a portion of the multilayer dielectric stack to form a dielectric mask structure using a pattern and etching process;    (D) removing a portion of the upper clad layer using the dielectric mask structure as a mask, and forming a laser diode structure having an exposed sidewall region and a top region while maintaining the dielectric mask structure substantially intact;    (E) selectively removing a portion of at least the first dielectric layers by a wet etch process to form an undercut region between second dielectric layers;    (F) depositing passivation layer(s) (1102) overlying a first surface region of the upper clad layer, the exposed sidewall region, and the dielectric mask structure, while maintaining the undercut region;    (G) removing the dielectric mask structure using a selective etch process, where the undercut region allows selective etch process to occur in a lateral direction;    (H) exposing a top surface region; and    (I) forming a contact structure overlying at least the top surface region.    DESCRIPTION OF DRAWING(S) - The drawing shows a simplified schematic diagram illustrating the method of forming a laser diode stripe.    Passivation layer (1102)