Method to improve metal defects in semiconductor device fabrication
The invention, in one aspect, provides a method of manufacturing a semiconductor device. This method includes providing a semiconductor substrate and depositing a metal layer over the semiconductor substrate that has an overall thickness of about 1 micron or greater. The metal layer is formed by depositing a first portion of the thickness of the metal layer, which has a compressive or tensile stress associated therewith over the semiconductor substrate. A stress-compensating layer is deposited over the first portion, such that the stress-compensating layer imparts a stress to the first portion that is opposite to the compressive or tensile stress associated with the first portion. A second portion of the thickness of the metal layer is then deposited over the stress-compensating layer.
1. A method of manufacturing a semiconductor device formed over a semiconductor substrate, comprising:
depositing a metal layer over a dielectric layer formed over the semiconductor substrate, the metal layer having an overall thickness of about 1 micron or greater, the metal layer formed by:
depositing a first portion of the metal layer over the dielectric layer, the first portion having a compressive or tensile stress associated therewith;
placing a stress-compensating layer over the first portion, such that the stress-compensating layer has a stress opposite to the compressive or tensile stress associated with the first portion;
depositing a second portion the metal layer over the stress-compensating layer; and
depositing and patterning a photoresist layer over the second portion of the metal layer; and
etching the metal layer to form the semiconductor device such that any remaining first portion of the metal layer remains entirely in contact with the dielectric layer.
2. The method recited in claim 1 , wherein the stress-compensating layer includes a metal selected from Group 4 or 5 of the Periodic Table.
3. The method recited in claim 2 , wherein the stress-compensating layer comprises titanium, tantalum, titanium nitride, tantalum nitride, or combinations thereof.
4. The method recited in claim 1 , wherein the metal layer comprises aluminum, copper, gold, silver, platinum, palladium, or combinations thereof.
5. The method recited in claim 1 , wherein the stress-compensating layer is a first stress-compensating layer and the method further includes depositing a second stress-compensating layer over the second portion, the second stress-compensating layer having a stress that is opposite to a compressive or tensile stress associated with the second portion, and depositing a third portion of the thickness, over the second stress-compensating layer.
6. The method recited in claim 5 , wherein a thickness of each of the first, second and third portions ranges from about 0.3 microns to about 0.8 microns.
7. The method recited in claim 5 , wherein different deposition parameters are used to from the first and second stress-compensating films.
8. The method recited in claim 1 , wherein the deposition parameters used to form the first and second portions include using an aluminum target and sputtering in an inert gas, such as argon, that has a flow ranging from about 10 sccm to about 30 sccm, at a pressure ranging from about 2500 mTorr to about 8500 mTorr, and at a power ranging from about 4000 to about 12000 watts.
9. The method recited in claim 1 , wherein depositing a second portion includes depositing a remaining portion to a predetermined thickness.
10. The method recited in claim 1 , wherein the metal layer is patterned to form an inductor for an integrated circuit.
11. The method recited in claim 1 , wherein the first portion has a stress associated therewith that ranges from about 1E8 to about 5E9 Pascals, and the stress-compensating layer has an opposite stress to that of the first portion that ranges from about 1E10 to about 3E10 Pascals.
12. The method recited in claim 1 , wherein placing a stress-compensating layer includes using a titanium target and flowing an inert gas with nitrogen to form a TiN layer wherein the inert gas is flowed at a flow rate ranging from about 5 sccm to about 30 sccm and the nitrogen is flowed at a rate ranging from about 5 sccm to about 30 sccm and at a pressure ranging from about 2500 mTorr to about 8500 mTorr and at a power ranging from about 2000 watts to about 8000 watts.
13. The method recited in claim 1 , wherein the stress-compensating layer is a first stress-compensating layer and the integrated circuit further includes a second stress-compensating layer over the second portion, and a third portion of the metal is located over the second stress-compensating layer.
14. A method of manufacturing an integrated circuit, comprising:
forming transistors over a semiconductor substrate;
forming dielectric layers over the transistors;
forming interconnects in the dielectric layers that electrically connect the transistors; and
forming an inductor over one of the dielectric layers, including:
depositing a metal layer over the semiconductor substrate, the metal layer having an overall thickness of about 1 micron or greater, the metal layer formed by:
depositing a first portion of the thickness of the metal layer over the one of the dielectric layers, the first portion having a compressive or tensile stress associated therewith;
placing a stress-compensating film over the first portion of the thickness of the metal layer, such that the stress-compensating film imparts a stress to the first portion opposite to the compressive or tensile stress associated with the first portion;
depositing a second portion of the thickness of the metal layer over the stress-compensating film; and
depositing and patterning a photoresist layer over the second portion of the thickness of the metal layer; and
etching the metal layer to form the inductor such that any remaining first portion of the thickness of the metal layer remains entirely in contact with the one of the dielectric layers.
15. The method recited in claim 14 , wherein the stress-compensating layer comprises titanium, tantalum, titanium nitride, tantalum nitride, or combinations thereof.
16. The method recited in claim 14 , wherein the metal layer comprises aluminum, copper, gold, silver, platinum, palladium, or combinations thereof.
17. The method recited in claim 14 , wherein the stress-compensating layer is a first stress-compensating layer and the method further includes depositing a second stress-compensating layer over the second portion, the second stress-compensating layer imparting a stress on the second portion that is opposite to a compressive or tensile stress associated with the second portion, and depositing a third portion of the thickness, over the second stress-compensating layer.
18. The method recited in claim 17 , wherein a thickness of each of the first, second and third portions ranges from about 0.3 microns to about 0.8 microns.
19. The method recited in claim 17 , wherein deposition parameters used to form the first and second portions include using an aluminum target and sputtering in an inert gas, such as argon, that has a flow ranging from about 10 sccm to about 30 sccm, at a pressure ranging from about 2500 mTorr to about 8500 mTorr, and at a power ranging from about 4000 to about 12000 watts.
20. The method recited in claim 14 , wherein placing a stress-compensating layer includes using a titanium target and flowing an inert gas with nitrogen to form a TiN layer wherein the inert gas is flowed at a flow rate ranging from about 5 sccm to about 30 sccm and the nitrogen is flowed at a rate ranging from about 5 sccm to about 30 sccm and at a pressure ranging from about 2500 mTorr to about 8500 mTorr and at a power ranging from about 2000 watts to about 8000 watts.
21. An integrated circuit, comprising:
transistors located over a semiconductor substrate;
dielectric layers located over the transistors;
interconnects located over or within in the dielectric layers that electrically connect the transistors; and
an inductor located over one of the dielectric layers comprising metal layer having a combined thickness of about 1 micron or greater, the metal layer including:
a first portion of the metal layer;
a stress-compensating layer located over the first portion; and
a second portion of metal layer located over the stress-compensating layer, wherein any remaining portion first portion of the metal layer remains entirely in contact with the one of the dielectric layers.
22. The integrated circuit recited in claim 21 , wherein the stress-compensating layer comprises titanium, tantalum, titanium nitride, tantalum nitride, or combinations thereof and the metal layer comprises aluminum, copper, gold, silver, platinum, palladium, or combinations thereof.
23. A method of manufacturing an integrated circuit, comprising:
forming transistors over a semiconductor substrate;
forming dielectric layers over the transistors;
forming interconnects in the dielectric layers that electrically connect the transistors; and
forming an inductor over one of the dielectric layers, including:
depositing a metal layer over the semiconductor substrate, the metal layer having an overall thickness of about 1 micron or greater, the metal layer remaining in contact with the semiconductor substrate and including:
depositing a first portion of the thickness of the metal layer over the semiconductor substrate, the first portion having a compressive or tensile stress associated therewith;
placing a first stress-compensating layer over the portion of the thickness of the metal layer, such that the first stress-compensating layer imparts a stress to the first portion opposite to the compressive or tensile stress associated with the first portion;
depositing a second portion of the thickness of the metal layer over the first stress-compensating layer;
depositing a second stress-compensating layer over the second portion, the second stress-compensating layer imparting a stress on the second portion that is opposite to a compressive or tensile stress associated with the second portion; and
depositing a third portion of the thickness over the second stress-compensating layer.