Patent ID: 8773803
Filing Date: 2014-07-08
Classification: G11B

Abstract:
1. A process to manufacture a thermal assistance feature, having good optical efficiency when generating a small thermal spot, for a magnetic write head having an air bearing surface (ABS) and a main pole with a sharp lower edge made of a first metal, comprising: providing an optical wave-guide having a refractive index in a range from 1.9 to 3.9 as well as a top surface; depositing a first layer of material on said top surface, said first layer having a low dielectric constant; through a mask, etching through said first layer to a level below said wave-guide top surface; removing said mask and said first layer of material thereby forming a triangular indentation in said top surface to a depth of between 5 and 40 nm, said triangular indentation extending along said top surface directly below said sharp lower edge made of a first metal and terminating at a point that is a distance from said ABS; to a depth that exceeds that of said triangular indentation, forming in said wave-guide top surface a trench located between said termination point and said ABS and abutting said triangular indentation; over-filling said trench with a second metal and then planarizing to form a filled trench until a top surface of said filled trench is coplanar with said wave-guide top surface, thereby forming a plasmon shield (PS) and a plasmon shield gap (PSG) between said PS and said main pole's sharp lower edge; and positioning said main pole so that the sharp lower edge lies above said wave-guide top surface to form a wave-guide edge plasmon gap (WEG) that is larger than said PSG, thereby achieving both good optical efficiency and a small optical spot.