Light-blocking layer sequence having one or more metal layers for an integrated circuit and method for the production of the layer sequence
AssigneeX-Fab Semiconductor Foundries AG
InventorDaniel Gaebler
Life of this patent
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Abstract
In an integrated circuit, a light sensitive area is protected against radiation by arranging a light blocking layer sequence (504) on top of the light sensitive area. The light blocking layer sequence comprises one or several metal layers (504a) and a silicon layer (503b, 1) for the purpose of absorption. A moth eye structure is provided on the silicon layer. Thereby, a radiation incident by reflection is minimized in such a way that also stray light can effectively be kept from the light sensitive area below the light blocking layer sequence (504).
Claims25
Integrated circuit having a first insulating layer applied on top of a substrate, and a light blocking layer sequence formed on the first insulating layer and comprising at least one metal layer arranged on the first insulating layer and a silicon layer located on one of the at least one metal layers, the surface of which is provided with a moth eye structure.
Method for the fabrication of a light blocking layer sequence in an integrated circuit comprising the steps of:
- applying a first metal layer of the light blocking layer sequence on first insulator layer where the first metal layer has a transmission of less than 1% for a specified wavelength range;
- depositing a silicon layer of the light blocking layer sequence with a thickness of at least 2 μm on the first metal layer;
- producing a moth eye structure in the silicon layer;
- patterning of the first metal layer and the silicon layer of the light blocking layer sequence by photolithography for laterally delimiting the light blocking layer sequence;
- depositing a second insulator layer or a layer with passivating effect on top of the moth eye structure.
Dependencies are inferred from the claim text.