Method of fabricating an integral capacitor and gate transistor having nitride and oxide polish stop layers using chemical mechanical polishing elimination
View Patent ↗A system, apparatus and/or method is provided for fabricating an integrated capacitor during the fabrication of a transistor employing chemical mechanical polishing of a gate electrode of the transistor. Components of the integrated capacitor, particularly the lower electrode of a parallel plate capacitor in one form thereof, and an outer plate of a cylindrical-like capacitor in another form thereof, are defined by the polish stop layer during chemical mechanical polishing (CMP) of a gate of the transistor. According to an aspect of the subject invention, the polish stop layer may be an oxide or a nitride.
1. A method of fabricating a capacitor on a substrate comprising the steps of:
performing capacitor foundation formation on the substrate;
depositing polish stop layer material on the capacitor foundation and the substrate;
etching a first capacitor electrode region on the capacitor foundation formation and a transistor gate region on the substrate;
depositing a first conductive material in the etched first capacitor electrode region and the transistor gate region;
performing chemical mechanical polishing on the deposited first conductive material to yield a gate electrode and a first capacitor electrode;
depositing a dielectric material over the gate electrode and the first capacitor electrode;
etching a second capacitor electrode region in the dielectric material over the first capacitor electrode and into the first capacitor electrode material;
forming a capacitor dielectric layer over the first capacitor electrode;
depositing a second conductive material in the etched second capacitor electrode region; and
performing chemical mechanical polishing on the deposited second conductive material to yield a second capacitor electrode.
2. The method of claim 1 , wherein the step of depositing polish stop layer material on the capacitor foundation substrate includes depositing polish stop layer material comprising an oxide.
3. The method of claim 1 , wherein the step of depositing polish stop layer material on the capacitor foundation substrate includes depositing polish stop layer material comprising a nitride.
4. The method of claim 1 , wherein the steps of performing chemical mechanical polishing on the deposited first conductive material to yield a first capacitor electrode yields a first electrode in the form of a plate, and performing chemical mechanical polishing on the deposited second conductive material to yield a second capacitor electrode yields a second electrode in the form of a plate.
5. The method of claim 1 , wherein the steps of performing chemical mechanical polishing on the deposited first conductive material to yield a first capacitor electrode yields a first substantially cylindrical electrode and performing chemical mechanical polishing on the deposited second conductive material to yield a second capacitor electrode yields a second substantially cylindrical electrode.