A method of forming a semiconductor device includes recessing the upper surface of first and second areas of a semiconductor substrate relative to the third area of the substrate, forming a pair of stack structures in the first area each having a control gate over a floating gate, forming a first source region in the substrate between the pair of stack structures, forming an erase gate over the first source region, forming a block of dummy material in the third area, forming select gates adjacent the stack structures, forming high voltage gates in the second area, forming a first blocking layer over at least a portion of one of the high voltage gates, forming silicide on a top surface of the high voltage gates which are not underneath the first blocking layer, and replacing the block of dummy material with a block of metal material.

A method of forming memory cells, HV devices and logic devices on a substrate, including recessing the upper surface of the memory cell and HV device areas of the substrate, forming a polysilicon layer in the memory cell and HV device areas, forming first trenches through the first polysilicon layer and into the silicon substrate in the memory cell and HV device areas, filling the first trenches with insulation material, forming second trenches into the substrate in the logic device area to form upwardly extending fins, removing portions of the polysilicon layer in the memory cell area to form floating gates, forming erase and word line gates in the memory cell area, HV gates in the HV device area, and dummy gates in the logic device area from a second polysilicon layer, and replacing the dummy gates with metal gates that wrap around the fins.

Provided is a method of manufacturing a semiconductor device including: providing a substrate having a memory cell region and a logic region; forming a plurality of stack structures on the substrate in the memory cell region; forming a polysilicon layer to cover the plurality of stack structures and the substrate in the logic region; performing a chemical-mechanical polishing (CMP) process on the polysilicon layer to expose top surfaces of the plurality of stack structures; and after performing the CMP process, patterning the polysilicon layer to form an erase gate between adjacent two stack structures and form a logic gate on the substrate in the logic region, wherein the logic gate has a topmost top surface lower than a topmost top surface of the erase gate.

Provided is a method of manufacturing a semiconductor device including: providing a substrate having a memory cell region and a logic region; forming a plurality of stack structures on the substrate in the memory cell region; forming a polysilicon layer to cover the plurality of stack structures and the substrate in the logic region; performing a chemical-mechanical polishing (CMP) process on the polysilicon layer to expose top surfaces of the plurality of stack structures; and after performing the CMP process, patterning the polysilicon layer to form an erase gate between adjacent two stack structures and form a logic gate on the substrate in the logic region, wherein the logic gate has a topmost top surface lower than a topmost top surface of the erase gate.

A process for fabricating an integrated circuit includes the fabrication of a first transistor and a floating-gate transistor. The fabrication process for the first transistor and the floating-gate transistor utilizes a common step of forming a dielectric layer. This dielectric layer is configured to form a tunnel-dielectric layer of the floating-gate transistor (which allows transfer of charge via the Fowler-Nordheim effect) and to form a gate-dielectric layer of the first transistor.

A method of forming a semiconductor device where memory cells and some logic devices are formed on bulk silicon while other logic devices are formed on a thin silicon layer over insulation over the bulk silicon of the same substrate. The memory cell stacks, select gate poly, and source regions for the memory devices are formed in the memory area before the logic devices are formed in the logic areas. The various oxide, nitride and poly layers used to form the gate stacks in the memory area are formed in the logic areas as well. Only after the memory cell stacks and select gate poly are formed, and the memory area protected by one or more protective layers, are the oxide, nitride and poly layers used to form the memory cell stacks removed from the logic areas, and the logic devices are then formed.

Various embodiments of the present application are directed to an integrated circuit (IC) comprising a floating gate test device, as well as a method for forming the IC. In some embodiments, the IC comprises a memory cell structure including a pair of control gates respectively separated from a substrate by a pair of floating gates and a pair of select gate electrodes disposed on opposite sides of the pair of control gates. A memory test structure includes a pair of dummy control gates respectively separated from the substrate by a pair of dummy floating gates and a pair of dummy select gate electrodes disposed on opposite sides of the pair of dummy control gates. The memory test structure further includes a pair of conductive floating gate test contact vias respectively extending through the pair of dummy control gates and reaching on the dummy floating gates.

Various embodiments of the present application are directed towards a method to integrate NVM devices with a logic or BCD device. In some embodiments, an isolation structure is formed in a semiconductor substrate. The isolation structure demarcates a memory region of the semiconductor substrate, and further demarcates a peripheral region of the semiconductor substrate. The peripheral region may, for example, correspond to BCD device or a logic device. A doped well is formed in the peripheral region. A dielectric seal layer is formed covering the memory and peripheral regions, and further covering the doped well. The dielectric seal layer is removed from the memory region, but not the peripheral region. A memory cell structure is formed on the memory region using a thermal oxidation process. The dielectric seal layer is removed from the peripheral region, and a peripheral device structure including a gate electrode is formed on the peripheral region.

Various embodiments of the present application are directed towards a method to integrate NVM devices with a logic or BCD device. In some embodiments, an isolation structure is formed in a semiconductor substrate. The isolation structure demarcates a memory region of the semiconductor substrate, and further demarcates a peripheral region of the semiconductor substrate. The peripheral region may, for example, correspond to BCD device or a logic device. A doped well is formed in the peripheral region. A dielectric seal layer is formed covering the memory and peripheral regions, and further covering the doped well. The dielectric seal layer is removed from the memory region, but not the peripheral region. A memory cell structure is formed on the memory region using a thermal oxidation process. The dielectric seal layer is removed from the peripheral region, and a peripheral device structure including a gate electrode is formed on the peripheral region.

A semiconductor structure including a semiconductor substrate and at least one patterned dielectric layer is provided. The semiconductor substrate includes a semiconductor portion, at least one first device, at least one second device and at least one first dummy ring. The at least one first device is disposed on a first region surrounded by the semiconductor portion. The at least one second device and the at least one first dummy ring are disposed on a second region, and the second region surrounds the first region. The at least one patterned dielectric layer covers the semiconductor substrate.