Two square NVRAM cell
First Claim
1. A non-volatile random access memory (NVRAM) array of one or more pairs of NVRAM cells, each cell of said pairs of NVRAM cells comprising:
- a word line select device having a first conduction terminal connected to a bit line and gated by a word line;
a floating gate device having a first conduction terminal connected to a second conduction terminal of said word line device; and
a source device having a first conduction terminal connected to a second conduction terminal of said floating gate device and gated by a source gate line, the bit line and word line being common to both cells of each said pair of NVRAM cells.
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Accused Products
Abstract
A non-volatile random access memory (NVRAM) cell and method of fabrication thereof. Pairs of NVRAM cells, each including three FETs stacked in a NAND-like structure are formed vertically in silicon pillars. Source devices at the bottom of the pillar selectively provide ground to one of the cells. A floating gate extends upward from the source device'"'"'s gate line. A control gate plate extending between adjacent pillars selectively provides a programming voltage to the control gate. Both the source gate and the control gate are capacitively coupled through silicon rich oxide to the floating gate. Polysilicon plugs between silicon pillars are word line gates for cells in adjacent pillars. A diffusion at the top of each pillar is a bit line contact for both cells at the pillar. Each pair of cells on a pillar are on a common bit line and a common word line. The word line, control gate and source gate line select individual cells in the pair.
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Citations
10 Claims
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1. A non-volatile random access memory (NVRAM) array of one or more pairs of NVRAM cells, each cell of said pairs of NVRAM cells comprising:
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a word line select device having a first conduction terminal connected to a bit line and gated by a word line; a floating gate device having a first conduction terminal connected to a second conduction terminal of said word line device; and a source device having a first conduction terminal connected to a second conduction terminal of said floating gate device and gated by a source gate line, the bit line and word line being common to both cells of each said pair of NVRAM cells. - View Dependent Claims (2, 3, 4, 5)
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6. A non-volatile random access memory (NVRAM) array of a plurality of pairs of NVRAM cells, each of said pairs of NVRAM cells comprising:
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a silicon pillar extending upward from a silicon layer; a bit line diffusion at the top end of said pillar; a pair of diffusions in said silicon layer on opposite sides of said silicon pillar; a source gate extending upward along said silicon pillar from each of said diffusions; a floating gate extending upward from each said source gate along said silicon pillar; a control gate extending upward from each said source gate parallel and capacitively coupled to said floating gate; a word line plug on each of said opposite sides disposed above each said control gate and along said silicon pillar between said floating gate and said bit line diffusion. - View Dependent Claims (7, 8, 9, 10)
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Specification