Isolation trench in semiconductor substrate with nitrogen-containing barrier region, and process for forming same
First Claim
1. A process for forming an improved isolation trench in a silicon semiconductor substrate containing nitrogen atoms formed in said trench which comprises:
- a) forming an isolation trench in a silicon semiconductor substrate;
b) forming in said isolation trench a barrier region by treating said trench structure with nitrogen atoms from a nitrogen plasma, said barrier region formed contiguous with the silicon semiconductor substrate surfaces of said isolation trench; and
c) forming a silicon oxide layer over said barrier region in said trench to confine said nitrogen atoms in said barrier region be the steps of;
i) forming an amorphous silicon layer over said barrier region in said trench, andii) then oxidizing said layer of amorphous silicon to form said layer of silicon oxide over said barrier region in said trench.
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Abstract
An isolation trench in a silicon semiconductor substrate is provided with a barrier region containing nitrogen atoms formed in the trench, contiguous with the silicon semiconductor substrate surfaces of the trench. The novel isolation trench structure of the invention is formed by forming an isolation trench in a silicon semiconductor substrate; forming in the isolation trench a barrier region by treating the trench structure with nitrogen atoms from a nitrogen plasma; and then forming a silicon oxide layer over the barrier region in the trench to confine the nitrogen atoms in the barrier region. In a preferred embodiment, a silicon oxide liner is first formed over the silicon semiconductor substrate surfaces of the trench, and then the trench structure is treated with nitrogen atoms from a nitrogen plasma to form, on the silicon semiconductor substrate surfaces of the trench, a barrier layer which contains silicon atoms, oxygen atoms, and nitrogen atoms.
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Citations
17 Claims
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1. A process for forming an improved isolation trench in a silicon semiconductor substrate containing nitrogen atoms formed in said trench which comprises:
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a) forming an isolation trench in a silicon semiconductor substrate; b) forming in said isolation trench a barrier region by treating said trench structure with nitrogen atoms from a nitrogen plasma, said barrier region formed contiguous with the silicon semiconductor substrate surfaces of said isolation trench; and c) forming a silicon oxide layer over said barrier region in said trench to confine said nitrogen atoms in said barrier region be the steps of; i) forming an amorphous silicon layer over said barrier region in said trench, and ii) then oxidizing said layer of amorphous silicon to form said layer of silicon oxide over said barrier region in said trench. - View Dependent Claims (2, 3, 4, 5)
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6. A process for forming an improved isolation trench in a silicon semiconductor substrate comprising a barrier region formed in said trench which inhibits penetration of dopant from said silicon semiconductor substrate into said isolation trench which comprises:
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a) forming an isolation trench in a silicon semiconductor substrate; b) forming a first silicon oxide layer over the silicon semiconductor substrate surfaces in said trench; c) then treating said first silicon oxide layer with nitrogen atoms from a nitrogen plasma to form on said silicon semiconductor substrate surfaces of said trench a barrier region containing silicon atoms, oxygen atoms, and nitrogen atoms, said barrier region contiguous with the surfaces of said isolation trench; and d) then forming a second silicon oxide layer over said barrier region in said trench to act as a cap layer to confine said nitrogen atoms in said barrier region said second silicon oxide layer formed by the steps of; i) forming an amorphous silicon layer over said barrier region in said trench; and ii) then oxidizing said layer of amorphous silicon to form said layer of silicon oxide over said barrier region in said trench. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14)
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15. An improved isolation trench in a silicon semiconductor substrate comprising a barrier region containing nitrogen atoms in said trench which comprises:
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a) an isolation trench formed in a silicon semiconductor substrate; b) a barrier region containing nitrogen atoms formed in said isolation trench by treating said trench structure with nitrogen atoms from a nitrogen plasma, said barrier region formed contiguous with the silicon semiconductor substrate surfaces of said isolation trench; and c) a silicon oxide layer formed over said barrier region in said trench to confine said nitrogen atoms in said barrier region, said silicon oxide layer comprising an amorphous silicon layer formed over said barrier region in said trench and then oxidized to form said layer of silicon oxide over said barrier region in said trench. - View Dependent Claims (16, 17)
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Specification