Method of fabricating local interconnects on a silicon-germanium 3D CMOS
First Claim
1. A method of fabricating local interconnect on a silicon-germanium 3D CMOS comprising:
- fabricating an active silicon CMOS device, having a gate, on a silicon substrate;
depositing an insulator layer on the silicon substrate;
opening a seed window through the insulator layer to the silicon substrate and to the gate of the silicon CMOS device;
depositing a germanium thin film on the insulator layer, wherein the germanium fills the windows forming a contact between the germanium thin film and the silicon substrate, and between the germanium thin film and the silicon CMOS device;
patterning and etching the germanium thin film;
encapsulating the germanium thin film in a dielectric material;
rapid thermal annealing the wafer and the layers formed thereon at a temperature sufficient to flow the germanium, while maintaining the other layers in a solid condition;
cooling to solidify the germanium as single crystal germanium and as polycrystalline germanium;
fabricating a germanium CMOS on the single crystal germanium thin film; and
using germanium taken from the forms of germanium consisting of single crystal germanium and polycrystalline germanium to from local interconnects between the silicon CMOS and the germanium CMOS.
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Accused Products
Abstract
A method of fabricating local interconnect on a silicon-germanium 3D CMOS includes fabricating an active silicon CMOS device on a silicon substrate. An insulator layer is deposited on the silicon substrate and a seed window is opened through the insulator layer to the silicon substrate and to a silicon CMOS device gate. A germanium thin film is deposited on the insulator layer and into windows, forming a contact between the germanium thin film and the silicon device. The germanium thin film is encapsulated in a dielectric material. The wafer is heated at a temperature sufficient to flow the germanium, while maintaining the other layers in a solid condition. The wafer is cooled to solidify the germanium as single crystal germanium and as polycrystalline germanium, which provides local interconnects. Germanium CMOS devices may be fabricated on the single crystal germanium thin film.
194 Citations
14 Claims
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1. A method of fabricating local interconnect on a silicon-germanium 3D CMOS comprising:
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fabricating an active silicon CMOS device, having a gate, on a silicon substrate;
depositing an insulator layer on the silicon substrate;
opening a seed window through the insulator layer to the silicon substrate and to the gate of the silicon CMOS device;
depositing a germanium thin film on the insulator layer, wherein the germanium fills the windows forming a contact between the germanium thin film and the silicon substrate, and between the germanium thin film and the silicon CMOS device;
patterning and etching the germanium thin film;
encapsulating the germanium thin film in a dielectric material;
rapid thermal annealing the wafer and the layers formed thereon at a temperature sufficient to flow the germanium, while maintaining the other layers in a solid condition;
cooling to solidify the germanium as single crystal germanium and as polycrystalline germanium;
fabricating a germanium CMOS on the single crystal germanium thin film; and
using germanium taken from the forms of germanium consisting of single crystal germanium and polycrystalline germanium to from local interconnects between the silicon CMOS and the germanium CMOS. - View Dependent Claims (2, 3, 4)
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5. A method of fabricating local interconnect on a silicon-germanium 3D CMOS SRAM cell comprising:
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fabricating a silicon gate transistor;
fabricating a silicon NMOS pull down transistor and a silicon NMOS pass gate transistor;
fabricating a germanium-on-insulator thin film by liquid phase epitaxy;
fabricating a germanium PMOS pull up transistor; and
forming a germanium local interconnect to connect the germanium PMOS pull-up transistor, the silicon NMOS pull-down transistor and the silicon NMOS pass gate transistor. - View Dependent Claims (6, 7, 8, 9, 10)
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11. A method of fabricating local interconnect on a silicon-germanium 3D CMOS comprising:
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preparing a silicon substrate wafer;
depositing a gate dielectric layer and forming a gate thereon;
fabricating an active silicon CMOS device, having a device gate, on the silicon substrate;
depositing an insulator layer on the silicon substrate;
opening a window through the insulator layer to the silicon substrate and to the device gate;
depositing a germanium thin film on the insulator layer, wherein the germanium fills the windows forming a contact between the germanium thin film and the silicon substrate, and between the germanium thin film and the silicon CMOS device;
patterning and etching the germanium thin film;
encapsulating the germanium thin film with a dielectric material;
annealing the wafer and the layers formed thereon at a temperature sufficient to flow the germanium, while maintaining the other layers in a solid condition; and
cooling the wafer and the layers formed thereon to provide for liquid phase epitaxy of the germanium to form a single crystal germanium layer and a polycrystalline germanium layer, wherein the single crystal germanium layer is used for subsequent germanium CMOS fabrication and wherein the polycrystalline germanium layer and single crystal germanium layer are used for local interconnects. - View Dependent Claims (12, 13, 14)
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Specification