Simultaneous formation of FinFET and MUGFET
View Patent ↗A method and structure comprise a field effect transistor structure that includes a first rectangular fin structure position on a substrate. The first rectangular fin structure has a bottom contacting the substrate, a top opposite the bottom, and sides between the top and the bottom. The structure additionally includes a second rectangular fin structure position on the substrate. Similarly, the second rectangular fin structure also has a bottom contacting the substrate, a top opposite the bottom, and sides between the top and the bottom. The sides of the second rectangular fin structure are parallel to the sides of the first rectangular fin structure. Further, a trench insulator is positioned on the substrate and is positioned between a side of the first rectangular fin structure and a side of the second rectangular fin structure. Additionally, a gate conductor is positioned on the trench insulator, positioned over the sides and the top of the first rectangular fin structure, and positioned over the sides and the top of the second rectangular fin structure. The gate conductor runs perpendicular to the sides of the first rectangular fin structure and the sides of the second rectangular fin structure. Also, a gate insulator is positioned between the gate conductor and the first rectangular fin structure and between the gate conductor and the second rectangular fin structure. The structure further includes a first cap on the top of the first rectangular fin structure. The first cap separates the gate conductor from the first rectangular fin structure.
1. A method, comprising:
forming trench isolation regions in a silicon layer of a substrate to define a first silicon region and a second silicon region bounded by said trench isolation regions;
patterning a first hardmask layer to form a first hardmask island on said first silicon region and a second hardmask island on said second silicon region;
patterning a second hardmask layer to form a third hardmask island on said first hardmask island and a fourth hardmask island on said second hardmask island;
removing said fourth hardmask island from said second hardmask island;
patterning first and second mandrels over said first silicon region and said second silicon region;
forming a third hardmask layer over said substrate;
removing said first and second mandrels to form openings in said third hardmask layer and to uncover exposed areas of said first silicon region and said second silicon region;
etching trenches into said exposed areas of said first silicon region and said second silicon region; and
removing said second hardmask island.
2. The method according to claim 1 , further comprising removing said third hardmask island from said first hardmask island.
3. The method according to claim 1 , said substrate comprising a silicon-on-insulator substrate comprising said silicon layer on a buried oxide layer, said etching of said second trenches to said third depth exposes said buried oxide layer.
4. The method according to claim 1 , said first silicon region and said second silicon region being one of:
adjacent one another and forming parts of a single transistor device; and
separated from one another on said substrate, and forming parts of different transistor devices on said substrate.
5. The method according to claim 1 , said first silicon region comprising a multiple gate field effect transistor (MUGFET) and said second silicon region comprising a fin-type field effect transistor (FINFET).
6. A method, comprising:
forming trench isolation regions in a silicon layer of a substrate to define a first silicon region and a second silicon region bounded by said trench isolation regions;
patterning a first hardmask layer to form a first hardmask island on said first silicon region and a second hardmask island on said second silicon region;
patterning a second hardmask layer to form a third hardmask island on said first hardmask island and a fourth hardmask island on said second hardmask island;
removing said fourth hardmask island from said second hardmask island;
patterning first and second mandrels over said first silicon region and said second silicon region;
forming a third hardmask layer over said substrate;
removing said first and second mandrels to form openings in said third hardmask layer and to uncover exposed areas of said first silicon region and said second silicon region;
etching trenches into said exposed areas of said first silicon region and said second silicon region;
removing said second hardmask island;
patterning a source and drain protective layer over said first silicon region and said second silicon region, said source and drain protective layer protecting source and drain regions of said first silicon region and said second silicon region and leaving channel regions of said first silicon region and said second silicon region exposed;
forming a gate insulator on said channel regions;
patterning at least one gate conductor on said gate insulator;
removing said source and drain protective layer; and
implanting an impurity into said source and drain regions.
7. The method according to claim 6 , further comprising removing said third hardmask island from said first hardmask island.
8. The method according to claim 6 , said substrate comprising a silicon-on-insulator substrate comprising said silicon layer on a buried oxide layer, said etching of said second trenches to said third depth exposes said buried oxide layer.
9. The method according to claim 6 , said first silicon region and said second silicon region being one of:
adjacent one another and forming parts of a single transistor device; and
separated from one another on said substrate, and forming parts of different transistor devices on said substrate.
10. The method according to claim 6 , said first silicon region comprising a multiple gate field effect transistor (MUGFET) and said second silicon region comprising a fin-type field effect transistor (FINFET).