Method and apparatus for a dual-inlaid damascene contact to sensor
First Claim
1. A dual-inlaid damascene contact comprising:
- an electrically conductive layer;
a dielectric layer formed on the electrically conductive layer, the dielectric layer having a dual-inlaid cavity formed therein, the dual-inlaid cavity comprising a contact cavity formed in a portion of the dielectric layer, the contact cavity having a bottom surface, first sidewall surfaces, and an opening adjacent to a surface of the dielectric layer, anda via cavity formed in a portion of the dielectric layer, the via cavity having second sidewall surfaces that extend the contact cavity to the electrically conductive layer, the electrically conductive layer having a via surface defined by an exposed portion of the electrically conductive layer adjacent to the via cavity;
a damascene contact disposed in the dual-inlaid cavity and in electrical communication with the electrically conductive layer, the damascene contact extending from the via surface to a contact surface adjacent to the opening of the contact cavity; and
a semiconductor layer formed on the surface of the dielectric layer and positioned over a portion of the contact surface and in electrical communication with the contact surface, whereby the damascene contact forms an interconnect structure between the electrically conductive layer and the semiconductor layer.
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Accused Products
Abstract
A dual-inlaid damascene contact having a polished surface for directly communicating an electrically conductive layer to a semiconductor layer. A dielectric layer is formed on the electrically conductive layer. A dual-inlaid cavity is formed by etching a via cavity and a contact cavity into the dielectric layer. A damascene contact is formed by depositing tungsten into the dual-inlaid cavity. Chemical-mechanical polishing is used to planarize and smooth a surface of the damascene contact until the surface is coplanar with the dielectric layer. A semiconductor layer is then deposited on the damascene contact. The semiconductor layer can be the node of an amorphous silicon P-I-N photodiode. Electrical interconnection between the node of the photodiode and the electrically conductive layer is accomplished without using an intermediate electrode, and the smooth damascene contact improves surface adhesion, reduces contact resistance, and provides a discrete connection to the semiconductor layer. The damascene contact may be polished to provide a light reflective surface finish for reflecting light incident on the damascene contact back into the semiconductor layer to improve the quantum efficiency of the P-I-N photodiode.
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Citations
12 Claims
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1. A dual-inlaid damascene contact comprising:
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an electrically conductive layer; a dielectric layer formed on the electrically conductive layer, the dielectric layer having a dual-inlaid cavity formed therein, the dual-inlaid cavity comprising a contact cavity formed in a portion of the dielectric layer, the contact cavity having a bottom surface, first sidewall surfaces, and an opening adjacent to a surface of the dielectric layer, and a via cavity formed in a portion of the dielectric layer, the via cavity having second sidewall surfaces that extend the contact cavity to the electrically conductive layer, the electrically conductive layer having a via surface defined by an exposed portion of the electrically conductive layer adjacent to the via cavity; a damascene contact disposed in the dual-inlaid cavity and in electrical communication with the electrically conductive layer, the damascene contact extending from the via surface to a contact surface adjacent to the opening of the contact cavity; and a semiconductor layer formed on the surface of the dielectric layer and positioned over a portion of the contact surface and in electrical communication with the contact surface, whereby the damascene contact forms an interconnect structure between the electrically conductive layer and the semiconductor layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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Specification