FinFET method and structure with embedded underlying anti-punch through layer
First Claim
1. A method for forming a semiconductor device, comprising:
- separately forming n-type and p-type anti-punch through (APT) layers over or in a substrate surface, said n-type and p-type APT layers not overlapping one another;
forming fin material over said n-type and p-type APT layers by epitaxial growth of undoped silicon;
forming a masking pattern over said fin material, said masking pattern defining covered portions and uncovered portions;
etching said uncovered portions thereby removing said fin material, said n-type and p-type APT layers and extending into said substrate to form discrete fins from said fin material; and
forming shallow trench isolation (STI) structures between said discrete fins.
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Abstract
Methods and structures for forming semiconductor FinFET devices with superior repeatability and reliability include providing APT (anti-punch through) layer accurately formed beneath a semiconductor fins, are provided. Both the n-type and p-type APT layers are formed prior to the formation of the material from which the semiconductor fin is formed. In some embodiments, barrier layers are added between the accurately positioned APT layer and the semiconductor fin. Ion implantation methods and epitaxial growth methods are used to form appropriately doped APT layers in a semiconductor substrate surface. The fin material is formed over the APT layers using epitaxial growth/deposition methods.
111 Citations
20 Claims
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1. A method for forming a semiconductor device, comprising:
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separately forming n-type and p-type anti-punch through (APT) layers over or in a substrate surface, said n-type and p-type APT layers not overlapping one another; forming fin material over said n-type and p-type APT layers by epitaxial growth of undoped silicon; forming a masking pattern over said fin material, said masking pattern defining covered portions and uncovered portions; etching said uncovered portions thereby removing said fin material, said n-type and p-type APT layers and extending into said substrate to form discrete fins from said fin material; and forming shallow trench isolation (STI) structures between said discrete fins. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for forming a semiconductor fin device, said method comprising:
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forming a first anti-punch through (APT) layer by epitaxial growth, said first APT layer being one of an n-type material and a p-type material; forming a barrier layer over said first APT layer; forming fin material over said barrier layer using epitaxial growth; forming discrete fins from said fin material by patterning and etching; forming shallow trench isolation (STI) structures in between said discrete fins; removing some of said discrete fins and corresponding underlying portions of said first APT layer and said barrier layer, thereby exposing portions of said substrate; forming a second APT layer by epitaxial growth on said portions of said substrate, said second APT layer being the other of said n-type and p-type material; and forming a barrier layer over said second epitaxial APT layer and a fin material over said barrier layer in said regions, thereby forming further discrete fins over said second APT layer. - View Dependent Claims (12, 13, 14, 15)
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16. A method for forming a semiconductor fin device, said method comprising:
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forming shallow trench isolation (STI) devices in a silicon substrate; recessing portions of said silicon substrate between said STI devices to form receded Si surfaces such that said STI devices extend above said receded Si surfaces, each said receded Si surface forming a bottom of a trench bounded by opposed STI devices; in some of said trenches, forming an n-type APT layer on said corresponding receded Si surface, forming a barrier layer over said n-type APT layer and forming a silicon fin material over said barrier layer thereby forming first Si fins; and in other of said trenches, forming a p-type APT layer on said corresponding receded Si surface, forming a barrier layer over said p-type APT layer and forming a silicon fin material over said barrier layer thereby forming second Si fins. - View Dependent Claims (17, 18, 19, 20)
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Specification