Winbond Electronics Corporation

Wen-Kuei Hsieh

James Juen Hsu

Hsi-Chuan Chen

Jung-Ho Chang

Sen-Huan Huang

Li-Ming Wang

Bor-Ru Sheu

Haochieh Liu

Hong-Hsiang Tsai

Chih-Mu Huang

A method for fabricating a floating gate of the flash memories is described. A pad oxide layer and a silicon nitride layer are formed sequentially on a substrate. A plurality of shallow trenches is formed in the substrate and an active area is defined by the shallow trenches. The silicon nitride layer is pulled back by isotropic etching to expose the corner of the trench. A corner-rounding process is performed to round the corner. An STI structure is formed in the shallow trench. Thereafter, the pad oxide layer and the silicon nitride layer are removed. A tunneling oxide layer and a first polysilicon layer are formed sequentially on the active area and the first polysilicon layer is as high as the STI structure. A second polysilicon layer is formed on the first polysilicon layer and the STI structures. A portion of the second polysilicon layer on the STI structure is removed to form the floating gate.

Method for fabricating a floating gate of flash rom

A method for manufacturing a memory device utilizes multi-etching processes to respectively construct isolation trenches in a memory substrate that has a memory array area and a peripheral circuit region, wherein the depth of the trenches in the peripheral circuit region is deeper into the memory substrate than the depth of the trenches in the memory array area. Therefore, possible current leakage caused from the high operating voltage is effectively mitigated, and the performance of the memory device is increased.

Memory device having isolation trenches with different depths and the method for making the same

A method of fabricating flash memory is provided. A substrate divided into a memory cell region and a peripheral circuit region is provided. After forming a first conductive layer over the substrate, the first conductive layer in the memory cell region is patterned to form a first gate conductive layer. Thereafter, a gate dielectric layer is formed over the substrate and then a second conductive layer and a passivation layer are sequentially formed over the gate dielectric layer. After removing the passivation layer, the second conductive layer and the first conductive layer in the peripheral circuit region, a third conductive layer is formed over the substrate. The third conductive layer and the passivation layer in the memory cell region are removed. The second conductive layer, the gate dielectric layer and the first gate conductive layer in the memory cell region are patterned to form a plurality of memory gates. Finally, the third conductive layer in the peripheral circuit region is patterned to form a plurality of gates.

Method of fabricating flash memory

A method for forming a smooth floating gate structure for a flash memory is disclosed. The method comprises the following steps. A substrate is firstly provided, and a first conductive layer and a second conductive layer are sequentially formed on the substrate. A first dielectric layer is then formed on the second conductive layer. A first hard mask layer and a second hard mask layer are formed sequentially on the first dielectric layer. A floating gate pattern is then transferred into the second hard mask layer to expose the first hard mask layer. The first hard mask layer is then etched to form a pattern and expose the first dielectric layer. A second dielectric layer is conformally formed over the second hard mask layer and the pattern; The second dielectric layer is etched back to form a spacer and expose the first dielectric layer. The first dielectric layer is then etched to expose the second conductive layer and the spacer, the second hard mask layer, the first hard mask layer and the first dielectric layer are finally removed.

Method for forming smooth floating gate structure for flash memory

A method of manufacturing an embedded DRAM. A substrate has a memory cell region and a logic circuit region. A plurality of gate conductors are formed on the substrate in the memory cell region and the logic circuit region. A spacer is formed on a sidewall of each gate conductor. An epitaxy layer is formed selectively on the exposed area of the substrate surface to service as source/drain regions in the logic circuit region and a source region and a drain region in the memory cell region. A silicide layer is formed on the epitaxy layer. A conformal buffer layer is formed over the substrate, and then a dielectric layer is formed over the substrate to cover the gate conductors. A mask is formed on the dielectric layer to expose a DRAM cell bit line contact region and a logic device source/drain contact region at the same time. A first etching step is performed to remove the dielectric layer by using the barrier layer as an etching stop layer. Then, a second etching step is performed to remove the barrier layer for exposing the silicide layer. As a result, a DRAM cell bit line contact and a logic device source/drain contact in the memory cell region and in the logic circuit region are formed at the same time by using the first etching step and the second etching step. Finally, metal plugs are formed within the DRAM cell bit line contact and the logic device source/drain contact simultaneously.

Method for manufacturing embedded dynamic random access memory

A method of manufacturing DRAM capacitor. An active region is formed above a substrate. A plurality of parallel word lines is formed above the substrate. A first plug and a second plug are formed between the word lines in locations for forming the desired bit line contact and node contact, respectively. Insulation material is deposited into the remaining space between the word lines. A bit line contact is formed above the first plug. A plurality of parallel bit lines is formed above the substrate. The bit lines are perpendicular to the word lines. The bit line is electrically connected to the substrate through the bit line contact and the first plug. The bit lines are electrically insulated from each other. Furthermore, each bit line is covered on top by a hard material layer. Finally, a node contact is formed over the second plug.

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Tainan Hsien, Taiwan

Wen-Kuei Hsieh