TFT mask ROM and method for making same
AssigneeMatrix Semiconductor, Inc.
InventorsAndrew J. Walker, Christopher Petti
Life of this patent
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Abstract
There is provided a monolithic three dimensional TFT mask ROM array. The array includes a plurality of device levels. Each of the plurality of device levels contains a first set of enabled TFTs and a second set of partially or totally disabled TFTs.
Claims24
A monolithic three dimensional TFT mask ROM array, comprising a plurality of device levels, wherein each device level of the plurality of device levels comprises a first set of enabled TFTs and a second set of partially or totally disabled TFTs.
A method of making a monolithic three dimensional TFT mask ROM array, comprising:
- forming a first device level comprising a plurality of TFTs over a substrate;
- forming a first mask over the first device level;
- partially or totally disabling a first set of TFTs in the first device level;
- forming a second device level comprising a plurality of TFTs over the first device level;
- forming a second mask over the second device level;
- and
- partially or totally disabling a second set of TFTs in the second device level;
- wherein:
- the array comprises a plurality of device levels;
- and
- each device level of the plurality of device levels comprises a first set of enabled TFTs and a second set of partially or totally disabled TFTs.
The method of 23, claim wherein the step of disabling a first set of TFTs in the first device level comprises forming a mask over the first semiconductor layer and selectively etching unmasked portions of the first semiconductor layer or selectively implanting ions into unmasked portions of the first semiconductor layer.
Dependencies are inferred from the claim text.