Macronix International Co., Ltd.

Wen Pin Lu

Nian-Kai Zous

I-Jen Huang

Ming Shiang Chen

Chun Chi Wang

Chi Yuan Chin

Chun Lien Su

Methods for programming and program verification of a flash memory are described that ease the buried drain contact induced operation and increase the retention window. In a first aspect of the invention, a program operation method provides varying program biases which are applied to different groups of memory cells. The program biases can be supplied as drain bias voltages or gate bias voltages. The program biases vary depending on which group of memory cells is programmed. In one embodiment, a first drain voltage Vis applied to the first group of memory cells Mand M. A second drain voltage Vis applied to the second group of memory cells Mand M, where V=V+&#x394;V. In a second aspect of the invention, a plurality of program verification voltage levels are selected to verify that the memory cells pass the program voltage levels.

Variable program and program verification methods for a virtual ground memory in easing buried drain contacts

A method of forming junction isolation to isolate active elements. A substrate having a plurality of active areas and an isolation area between active areas is provided. A first gate structure is formed on part of the substrate located in the active areas and, simultaneously, a second gate structure serving as a dummy gate structure is formed on the substrate located in the isolation area. A first doped region is formed in the substrate located at two sides of the first and the second gate structures. A bottom anti-reflection layer is formed on the substrate, the first gate structure and the second gate structure. Part of the bottom anti-reflection layer is etched to expose the second gate structure. The second gate structure is removed to expose the substrate. A second doped region serving as a junction isolation region is formed in the substrate located in the isolation area.

Method of forming junction isolation to isolate active elements

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Hsinchu, Taiwan

Wen Pin Lu