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US 6,018,186 AGranted
Three-dimensional, deep-trench, high-density read-only memory (ROM) and its manufacturing method
AssigneeUnited Microelectronics Corp.
InventorChen-Chung Hsu
Life of this patent
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Abstract
A three-dimensional, deep-trench, high-density ROM and its manufacturing method are provided. The ROM device comprises a silicon substrate having a plurality of parallel trenches above it surface, wherein, between every two adjacent trenches, there is a higher region. During programming of the ROM device, deeper trenches are formed to define the OFF-state non-conducting memory cells, so that misalignment problems that lead to transistor cell leakage are prevented. The ROM device provides reduced breakdown of the source/drain regions as well.
Claims6
A three-dimensional, high-density ROM, comprising:
- a plurality of parallel bit lines formed in a silicon substrate, each of the bit lines having a depth substantially equal to the depth of the other bit lines;
- a plurality of word lines running perpendicular to and above the bit lines;
- and
- a plurality of memory cells, each memory cell being formed at a junction of two adjacent bit lines and a portion of one of the word lines and having a channel region, the channel region having a depth and containing gate oxide and polysilicon, the plurality of memory cells including a plurality of non-conducting memory cells and a plurality of conducting memory cells, the channel region of the conducting memory cells having a depth substantially equal to the depth of the plurality of bit lines, the channel region of the non-conducting memory cells having a depth greater than the depth of the channel region of the conducting memory cells and penetrating through the bit lines.
1 more element
Dependencies are inferred from the claim text.