Method for production of selective growth masks using underfill dispensing and sintering

A method for production of selective growth masks using underfill dispensing and sintering, comprising following steps of:

• providing a sapphire substrate, wherein the sapphire substrate is a base for growing subsequent films;
• growing a gallium nitride base layer on the sapphire substrate;
• coating a photoresist layer, wherein the photoresist layer is formed by coating a photoresist material on the gallium nitride base layer formed on the sapphire substrate;
• performing imprint lithography, exposure and development, wherein the imprint lithography is to imprint a pattern of holes on the photoresist layer, and the exposure and development is to illuminate the imprinted photoresist layer by a light source so as to transfer the pattern of the holes to the photoresist layer and form a protruding dam of the photoresist layer;
• performing underfill dispensing, wherein an insulating material is filled into a plurality of gaps exposed from the underlying gallium nitride base layer and disposed outside the protruding dam of the photoresist layer;
• and
• performing sintering, wherein a heating process is applied to remove the photoresist layer, and the insulating material disposed outside the protruding dam of the photoresist layer forms an insulating layer and acts as a selective growth mask on the gallium nitride base layer.