Process to form a mold of nanoimprint technique for making diffraction grating for dfb-ld
AssigneeSumitomo Electric Industries, Ltd.
InventorMasaki Yanagisawa
Life of this patent
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Abstract
A process using the nanoimprint technique to form the diffraction grating for the DFB-LD is disclosed. The process includes (a) coating a resist for the EB exposure on a dummy substrate, (b) irradiating the resist as varying the acceleration voltage, (c) forming a resist pattern by developing the irradiated resist, (d) coating the SOG film on the patterned resist, (e) attaching the silica substrate on the cured SOG film, and (f) removing the dummy substrate with the resist from the SOG film and the silica substrate. Using the mold thus formed, the diffraction grating for the DFB-LD is formed by the nanoimprint technique.
Claims8
1-6. (canceled)
A method for forming a diffraction grating, comprising steps of:
- forming a plurality of semiconductor layers on a semiconductor substrate;
- preparing a mold that includes a particular pattern reflecting a diffraction grating having an aspect ratio, a duty ratio and a pitch, said mold including a plurality of regions each having at least one of said aspect ratio, said duty ratio and said pitch specific to said region and different from other regions;
- coating a photo resist on said semiconductor layers;
- printing said particular pattern of said mold on said photo resist to form a resist pattern by pressing said pattern of said mold on said photo resist and hardening said photo resist as said mold presses on said photo resist;
- and
- etching said semiconductor layers to reflect said particular pattern of said mold on said semiconductor layers by using said resist pattern as an etching mask.
A method to form a distributed feedback laser diode, comprising steps of:
- forming semiconductor layers including an active layer and a guiding layer on a semiconductor substrate;
- preparing a mold that includes a particular pattern reflecting a diffraction grating having an aspect ratio, a duty ratio and a pitch, said mold including a plurality of regions each having at least one of said aspect ratio, said duty ratio and said pitch specific to said region and different from other regions;
- coating said semiconductor layer with a photo resist for nano-imprinting;
- printing said particular pattern of said mold on said photo resist to form a resist pattern by pressing said pattern of said mold on said photo resist and hardening said photo resist as said mold presses on said photo resist;
- etching said guiding layer to reflect said particular pattern of said mold on said semiconductor layers by using said resist pattern as an etching mask;
- and
- forming a cladding layer on said guiding layer.
Dependencies are inferred from the claim text.