Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
234 words
A method of forming an array of memory cells, each memory cell formed at a semiconductor pillar of a first conductivity type, said pillar having a multisided cross-section, for each memory cell said method comprising the steps of: (a) forming a capacitor, said step of forming a capacitor comprising the steps of: i. forming a storage dielectric film surrounding said pillar near the bottom; and ii. forming a field plate surrounding said storage dielectric film; (b) biasing said field plate to a voltage sufficient to form an inversion region surrounding said pillar on the other side of said storage dielectric film from said field plate; (c) forming a transistor, said step of forming a transistor comprising the steps of: i. doping a region at the top of said pillar of a second conductivity type connected to a bit line; ii. forming a single control gate associated with each said pillar, said control gate disposed only on a single one of the sides of said associated pillar above said field plate, said control gate separated from said pillar by a gate dielectric and extending between said inversion region and said doped region so that a voltage applied to said control gate controls the conduction path along said single side of said pillar between said doped region and said inversion region, said control gate comprising a semiconductive material and formed in contact with a metal wordline.
Claim 2
Independent Claim
234 words
A method of forming an array of memory cells, each memory cell formed at a semiconductor pillar of a first conductivity type, said pillar having a multisided cross-section, for each memory cell said method comprising the steps of: (a) forming a capacitor, said step of forming a capacitor comprising the steps of: i. forming a storage dielectric film surrounding said pillar near the bottom; and ii. forming a field plate surrounding said storage dielectric film; (b) biasing said field plate to a voltage sufficient to form an inversion region surrounding said pillar on the other side of said storage dielectric film from said field plate; (c) forming a transistor, said step of forming a transistor comprising the steps of: i. doping a region at the top of said pillar of a second conductivity type connected to a bit line; ii. forming a single control gate associated with each said pillar, said control gate disposed only on a single one of the sides of said associated pillar above said field plate, said control gate separated from said pillar by a gate dielectric and extending between said inversion region and said doped region so that a voltage applied to said control gate controls the conduction path along said single side of said pillar between said doped region and said inversion region, said control gate comprising a semiconductive material and formed in contact with a metal wordline.
Claim 3
Dependent Claim
13 words
The method of claim 1 wherein said semiconductor pillar comprises a silicon pillar.
Claim 4
Dependent Claim
10 words
The method of claim 2 wherein said control comprises polysilicon.
Claim 5
Dependent Claim
14 words
The method of claim 1 wherein said metal wordline comprises a refractory metal wordline.
Claim 6
Dependent Claim
13 words
The method of claim 4 wherein said metal wordline comprises a tungsten wordline.
Claim 7
Dependent Claim
18 words
The method of claim 1 wherein said metal wordline is formed by way of selective chemical vapor deposition.