Opto-coupling device structure and method therefor
AssigneeMotorola, Inc.
InventorsWilliam J. Taylor JR., Wei E. Wu, Sebastian M. Csutak
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Abstract
A manufacturing technique for making grating features utilizes the etching characteristics for photoresist to provide desirable geometric shapes in close proximity to each other. This results in a grating for optocoupling, which is manufacturable and provides efficient coupling. A silicon waveguide is conveniently achieved using a SOI substrate so that the insulator underlying the silicon provides one material adjoining the silicon with a lower index of refraction than silicon. The top surface of the silicon has the desirable geometric shapes that result also in a lower index of refraction than silicon above the main body of the silicon substrate.
Claims26
A method of detecting light, comprising:
- providing a first material, with a first refractive index;
- providing a second material over the first material, wherein the second material has a second refractive index and the second refractive index is greater than the first refractive index;
- providing a doped region in the second material;
- providing a third material with a third refractive index;
- depositing a photoresist layer over the third material;
- patterning the photoresist layer to leave a pattern of the photoresist;
- etching the third material according to the pattern of the photoresist;
- removing the photoresist;
- exposing at least a portion of the second material and the third material to the light to couple the light into the second material to generate carriers;
- and
- collecting carriers.
A method of forming an opto-coupling structure on a substrate having a silicon layer with a surface, comprising:
- forming a silicon oxide layer over the surface of the silicon layer;
- depositing a photoresist layer over the silicon oxide layer;
- patterning the photoresist layer to remove a first portion of the photoresist layer;
- etching the silicon oxide layer to leave a first pattern of silicon oxide and a second pattern of exposed silicon;
- roughing the exposed silicon;
- and
- applying an etchant comprising potassium, oxygen, and hydrogen to the first pattern of silicon oxide and the second pattern of exposed silicon to leave pyramid shaped silicon features according to the first pattern.
A method of forming an opto-coupling structure on a substrate having a semiconductor layer with a surface, wherein the semiconductor of the semiconductor layer has a crystal orientation, comprising:
- forming a first layer over the surface of the semiconductor layer;
- depositing a photoresist layer over the first layer;
- patterning the photoresist layer to remove a first portion of the photoresist layer;
- etching the first layer to leave a first pattern of the first layer and a second pattern of exposed semiconductor of the semiconductor layer;
- roughing the exposed semiconductor;
- and
- applying an etchant, which is selective to the orientation of the semiconductor and the first layer, to the first pattern of the first layer and the second pattern of the exposed semiconductor wherein geometric shapes are left according to the first pattern.
Dependencies are inferred from the claim text.