Method of fabricating a dynamic random access memory with increased capacitance
AssigneeTexas Instruments Incorporated
InventorsDarius L. Crenshaw, Promod Kumar
Life of this patent
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Abstract
A method for forming a dynamic random access memory with increased capacitance includes preparing (36) ultra-fine particles in a microemulsion. The particles are deposited (38) on the lower electrode layer of the memory cell. A micro-villus pattern is then formed (40) on the lower electrode layer, using the particles as a mask. A layer of HSG polysilicon may then be deposited (42) on the micro-villus pattern. A dielectric and upper electrode are then formed (44) overlying the lower electrode to form a storage capacitor for the dynamic random access memory.
Claims20
A method of forming a dynamic random access memory cell having a storage capacitor, comprising:
- precipitating a plurality of particles in a microemulsion mixture;
- forming a lower electrode layer;
- depositing the particles in an evenly spaced layer on the lower electrode layer;
- using the deposited particles as a mask to form a micro-villus pattern on the lower electrode layer;
- removing the particles leaving the micro-villus pattern on the lower electrode layer;
- forming a dielectric overlying the micro-villus pattern;
- and
- forming an upper electrode of the storage capacitor.
A method of forming a dynamic random access memory cell having a storage capacitor, comprising:
- precipitating a plurality of particles in a microemulsion mixture;
- forming a lower electrode layer;
- forming a mask layer overlying the lower electrode layer;
- depositing the particles in an evenly spaced layer on the mask layer;
- using the deposited particles to form a mask of the mask layer;
- using the mask to form a micro-villus pattern on the lower electrode layer;
- removing the particles from the lower electrode layer;
- forming a dielectric overlying the micro-villus pattern;
- and
- forming an upper electrode of the storage capacitor.
A method of forming a dynamic random access memory cell having a storage capacitor, comprising:
- precipitating a plurality of particles in a microemulsion mixture;
- separating the particles and making them hydrophilic;
- placing the particles in a water solution;
- evenly spacing the particles;
- forming a lower electrode layer;
- forming a layer of evenly spaced particles over the lower electrode layer;
- forming a micro-villus pattern on the lower electrode layer by etching the lower electrode layer using the layer of evenly spaced particles as a mask;
- removing the particles using an etch selective to said particles;
- forming a layer of rough polysilicon on the micro-villus pattern;
- forming a dielectric overlying the micro-villus pattern;
- and
- forming an upper electrode of the storage capacitor.
Dependencies are inferred from the claim text.