Abstract:
A method for manufacturing a split-gate flash memory cell, comprising the steps of forming an active region on a semiconductor substrate; forming a buffer layer on the semiconductor substrate; forming a first dielectric layer on the buffer layer; removing part of the first dielectric layer; defining an opening; removing the buffer layer within the opening; forming a gate insulating layer and floating gates; forming a source region in the semiconductor substrate; depositing a conformal second dielectric layer on the opening; removing the buffer layer outside the first dielectric layer and the floating gates; and forming an oxide layer and control gates.
Abstract:
A method for fabricating a flash memory cell. The method starts with sequential formation of a first insulating layer, a first conductive layer and pad layer on a semiconductor substrate. Part of the pad layer is removed to form a first opening, followed by forming a conductive spacer, i.e. the tip, on the sidewalls of the first opening. Then, parts of the pad layer, first conductive layer, first insulating layer and substrate are removed to form a second opening. Next, a second insulating layer is formed to fill the first opening and the second opening to form a first gate insulating layer and shallow trench isolation. The first gate insulating layer is used as hard mask to remove part of the first conductive layer and the first insulating layer to form a floating gate and a second insulating layer. Tunneling oxide and control gate are then formed on the floating gate. Finally, a source/drain is formed.
Abstract:
A method of fabricating a flash memory cell. The method includes the steps of providing a semiconductor substrate; forming a first gate insulating layer; forming a first conductive layer on the first gate insulating layer; forming a floating gate insulating layer; forming a source region by implanting impurity ions into the substrate; forming a second insulating layer; forming a floating gate region; forming a third insulating; forming a second conductive layer on the third insulating layer; forming a fourth insulating layer on the second conductive layer; forming a floating gate region; forming a second conductive layer on the third insulating layer; forming first sidewall spacers; forming control gates and a tunneling oxide; forming second sidewall spacers; and forming a drain region on the substrate.
Abstract:
A method for fabricating a capacitor over a semiconductor substrate is disclosed. The method includes the steps of: forming an insulating layer over the semiconductor substrate; forming a contact opening through the insulating layer to expose a portion of the semiconductor substrate; forming a first polysilicon layer over the insulating layer and filling in the contact opening to electrically contact the semiconductor substrate; patterning the first polysilicon layer to the insulating layer surface, thereby forming a trench for defining a capacitor region; forming a thin polysilicon layer with a rugged surface over the first polysilicon layer and the insulating layer; forming a mask layer over the thin polysilicon layer, wherein the mask layer has a smaller thickness in the trench bottom than in other regions; removing the mask layer in the trench bottom through an anisotropical etch step; removing the uncovered portions of the thin polysilicon layer to expose the insulating layer surface; removing the mask layer, thereby forming a storage electrode consisting of the thin polysilicon layer and the first polysilicon layer; forming a dielectric layer over the storage electrode and the exposed insulating layer; and forming a second polysilicon layer over the dielectric layer.
Abstract:
A floating gate and fabrication method thereof. A semiconductor substrate is provided, on which an oxide layer, a first conducting layer, and a patterned hard mask layer having an opening are sequentially formed. A spacer is formed on the sidewall of the opening. A second conducting layer is formed on the hard mask layer. The second conducting layer is planarized to expose the surface of the patterned hard mask layer. The surface of the second conducting layer is oxidized to form an oxide layer. The patterned hard mask layer and the oxide layer and the first conducting layer underlying the patterned hard mask layer are removed.
Abstract:
A vertical DRAM and fabrication method thereof. The vertical DRAM has a plurality of memory cells on a substrate, and each of the memory cells has a trench capacitor, a vertical transistor, and a source-isolation oxide layer in a deep trench. The main advantage of the present invention is to form an annular source diffusion and an annular drain diffusion of the vertical transistor around the sidewall of the deep trench. As a result, when a gate of the transistor is turned on, an annular gate channel is provided. The width of the gate channel of the present invention is therefore increased.
Abstract:
A method for fabricating a vertical nitride read-only memory (NROM) cell. A substrate having at least one trench is provided. A spacer is formed over the sidewall of the trench. Subsequently, ion implantation is performed on the substrate using the spacer as a mask to form doping areas as bit lines in the substrate near its surface and the bottom of the trench. Bit line oxides are formed over each of the doping areas. After the spacer is removed, a conformable insulating layer as gate dielectric is deposited on the sidewall of the trench and the surface of the bit line oxide. Finally, a conductive layer as a word line is deposited over the insulating layer and fills in the trench.
Abstract:
The present invention discloses a multi-bit stacked-type non-volatile memory having a spacer-shaped floating gate and a manufacturing method thereof. The manufacturing method includes forming a patterned dielectric layer containing arsenic on a semiconductor substrate, wherein the patterned dielectric layer defines an opening as an active area. A dielectric spacer is formed on a side wall of the patterned dielectric layer and a gate dielectric layer is formed on the semiconductor substrate. A source/drain region is formed by thermal driving method making arsenic diffusion from the patterned dielectric layer into the semiconductor substrate. A spacer-shaped floating gate is formed on the side wall of the dielectric spacer and the gate dielectric layer. An interlayer dielectric layer is formed on the spacer-shaped floating gate. A control gate is formed on the interlayer dielectric layer and fills the opening of the active area.
Abstract:
A stacked gate flash memory device and method of fabricating the same. A cell of the stacked gate flash memory device is disposed in a cell trench within a substrate to achieve higher integration of memory cells.
Abstract:
A method for fabricating a vertical nitride read-only memory (NROM) cell. A substrate having at least one trench is provided. A spacer is formed over the sidewall of the trench. Subsequently, ion implantation is performed on the substrate using the spacer as a mask to form doping areas as bit lines in the substrate near its surface and the bottom of the trench. Bit line oxides are formed over each of the doping areas. After the spacer is removed, a conformable insulating layer as gate dielectric is deposited on the sidewall of the trench and the surface of the bit line oxide. Finally, a conductive layer as a word line is deposited over the insulating layer and fills in the trench.