Method for fabricating reliable metallization with Ta-Si-N barrier for semiconductors
First Claim
1. A method for manufacturing a semiconductor device, said semiconductor device including a silicon substrate having at least one device element and a non-conductive layer at least partially covering said device element, said method comprising the steps of:
- etching a via extending through said non-conductive layer to said device element thereby providing an exposed region of said device element;
depositing a tantalum silicide ohmic contact layer over at least a first portion of said non-conductive layer and said via, said ohmic contact layer being in electrical contact with said exposed region;
depositing a tantalum silicon nitride barrier layer over at least a second portion of said non-conductive layer and said via, said barrier layer being in direct contact with said ohmic contact layer, and being in electrical contact with said exposed region; and
depositing a metallization layer upon said semiconductor device, said metallization layer formed over and in electrical contact with said exposed region, and wherein said metallization layer is aluminum or an aluminum containing alloy.
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Accused Products
Abstract
A method for manufacturing an ohmic contact on a semiconductor device, as disclosed herein, includes a first step of etching a via through a non-conductive layer formed over a partially fabricated version of the semiconductor device. This step exposes a region of a device element such as a source, gate electrode, etc. Next, an ohmic contact layer including tantalum and silicon is deposited over the partially fabricated device and in the vias by sputtering in an argon atmosphere. Thereafter, and in the same processing apparatus, a barrier layer including a tantalum silicon nitride is deposited over the ohmic contact layer. Then an aluminum alloy metallization layer is directly deposited on the partially fabricated device at a temperature of at least 650° C. At this deposition temperature, the metallization layer conformally fills the via, thereby producing a stable, uniform contact.
52 Citations
19 Claims
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1. A method for manufacturing a semiconductor device, said semiconductor device including a silicon substrate having at least one device element and a non-conductive layer at least partially covering said device element, said method comprising the steps of:
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etching a via extending through said non-conductive layer to said device element thereby providing an exposed region of said device element; depositing a tantalum silicide ohmic contact layer over at least a first portion of said non-conductive layer and said via, said ohmic contact layer being in electrical contact with said exposed region; depositing a tantalum silicon nitride barrier layer over at least a second portion of said non-conductive layer and said via, said barrier layer being in direct contact with said ohmic contact layer, and being in electrical contact with said exposed region; and depositing a metallization layer upon said semiconductor device, said metallization layer formed over and in electrical contact with said exposed region, and wherein said metallization layer is aluminum or an aluminum containing alloy. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method for manufacturing a semiconductor device, said semiconductor device including a silicon substrate having at least one device element and a non-conductive layer at least partially covering said device element, said method comprising the steps of:
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etching a via extending through said non-conductive layer to said device element thereby providing an exposed region of said device element; depositing a tantalum silicide ohmic contact layer over at least a first portion of said non-conductive layer and said via, said ohmic contact layer being in electrical contact with said exposed region; depositing tantalum silicon nitride barrier layer over at least a second portion of said non-conductive layer and said via, said barrier layer being in direct contact with said ohmic contact layer, and being in electrical contact with said exposed region; and depositing a metallization layer on top of said tantalum silicon nitride barrier layer, whereby said tantalum silicon nitride layer acts as a barrier to transport of atoms from said metallization layer to said silicon substrate, and wherein said metallization layer is aluminum, or an aluminum containing alloy. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19)
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Specification