Method of making metal-to-polysilicon capacitor
First Claim
1. A method for fabricating a capacitor at a surface of a semiconductor body, comprising the steps of:
- forming a field dielectric structure at a selected portion of said surface;
forming a refractory metal layer thereover in contact with said field dielectric structure and with a silicon surface of said semiconductor body;
reacting the refractory metal layer to form a silicide where in contact with said silicon surface;
removing selected portions of the refractory metal layer which was not reacted to form a silicide, to define a bottom plate overlying said field dielectric structure;
forming an interlevel dielectric layer overall;
removing a portion of said interlevel dielectric layer over said bottom plate to expose a portion of said bottom plate;
forming a capacitor dielectric over said exposed portion of said bottom plate; and
forming a top plate comprising a metal layer in contact with said capacitor dielectric over said bottom plate.
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Accused Products
Abstract
A metal-to-polysilicon capacitor, a floating-gate transistor containing such a capacitor, and a method for making the same is disclosed. The bottom plate of the capacitor is formed over a field oxide structure, and the multilevel dielectric is deposited thereover. The multilevel dielectric is removed from the capacitor area, and an oxide/nitride dielectric is deposited over the exposed bottom plate and over the multilevel by way of LPCVD. A first layer of titanium/tungsten is preferably deposited prior to contact etch, and the contacts to moat and unrelated polysilicon are formed. Metallization is sputtered overall, and the metal and titanium/tungsten are cleared to leave the metallization filling the contact holes, and a capacitor having a titanium/tungsten and metal top plate.
71 Citations
4 Claims
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1. A method for fabricating a capacitor at a surface of a semiconductor body, comprising the steps of:
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forming a field dielectric structure at a selected portion of said surface; forming a refractory metal layer thereover in contact with said field dielectric structure and with a silicon surface of said semiconductor body; reacting the refractory metal layer to form a silicide where in contact with said silicon surface; removing selected portions of the refractory metal layer which was not reacted to form a silicide, to define a bottom plate overlying said field dielectric structure; forming an interlevel dielectric layer overall; removing a portion of said interlevel dielectric layer over said bottom plate to expose a portion of said bottom plate; forming a capacitor dielectric over said exposed portion of said bottom plate; and forming a top plate comprising a metal layer in contact with said capacitor dielectric over said bottom plate. - View Dependent Claims (2, 3, 4)
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Specification