Abstract:
A method of fabricating a floating gate for a flash memory. An active region is formed on a semiconductor substrate. A first insulating layer, a first conductive layer and a masking layer are sequentially formed in the active region. A part of the masking layer is removed to form a first opening. A second conductive layer is formed to cover the masking layer and the bottom surface and sidewall of the first opening. A second insulating layer is formed on the second conductive layer to fill the first opening. An oxidation process is performed until the second conductive layer in contact with the second insulating layer over the masking layer is oxidized into a third insulating layer. The second and third insulating layers are removed to form a second opening. A fourth insulating layer fills in the second opening. The masking layer and the first conductive layer underlying the masking layer uncovered by the fourth insulating layer are removed.
Abstract:
The present invention provides a process for fabricating a floating gate of a flash memory. First, an isolation region is formed in a semiconductor substrate and the isolation region has a height higher than the substrate. A gate oxide layer and a first polysilicon layer are then formed. The first polysilicon layer is formed according to the contour of the isolation region to form a recess in the first polysilicon layer. A sacrificial insulator is filled into the recess. The first polysilicon layer is then selectively removed in a self-aligned manner using the sacrificial insulator as a hard mask to expose the isolation region. A polysilicon spacer is formed on the sidewalls of the first polysilicon layer. A first mask layer is formed on the isolation region, the sacrificial insulator in the recess is removed, and a floating gate region is defined. Then, the surfaces of the first polysilicon layer and polysilicon spacer in the floating gate region are oxidized to form a polysilicon oxide layer. Finally, the polysilicon oxide layer is used as a mask to pattern the underlying first polysilicon layer and polysilicon spacer in a self-aligned manner to form a floating gate. During the oxidation process, the polysilicon spacer of the present invention serves as a buffer layer, which is oxidized and protects the floating gate from being oxidized. Thus, the floating gate and STI overlay, and current leakage caused by insufficient overlay is prevented.
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 split gate flash memory cell. The memory cell includes a substrate, a conductive line, source/drain regions, an insulating layer, a conductive spacer, an insulating stud, a first conductive layer, and a first insulating spacer. The conductive line is disposed in a lower portion of the trench of the substrate. The source region is formed in the substrate adjacent to an upper portion of the conductive line having the insulating layer thereon. The conductive spacer is disposed on the upper sidewall of the trench serving as a floating gate. The insulating stud is disposed on the insulating layer. The first conductive layer is disposed over the substrate adjacent to the conductive spacer serving as a control gate. The first insulating spacer is disposed on the sidewall of the insulating stud to cover the first conductive layer. The drain region is formed in the substrate adjacent to the first conductive layer.
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:
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 split gate flash memory device and method of fabricating the same. A cell of the split gate flash memory device in accordance with the invention is disposed in a cell trench within a substrate to achieve higher integration of memory cells.
Abstract:
A stacked gate flash memory device and method of fabricating the same. A cell of the stacked gate flash memory device in accordance with the invention is disposed in a cell trench within a substrate to achieve higher integration of memory cells.
Abstract:
A split gate flash memory cell. The memory cell includes a substrate, a conductive line, source/drain regions, an insulating layer, a conductive spacer, an insulating stud, a first conductive layer, and a first insulating spacer. The conductive line is disposed in a lower portion of the trench of the substrate. The source region is formed in the substrate adjacent to an upper portion of the conductive line having the insulating layer thereon. The conductive spacer is disposed on the upper sidewall of the trench serving as a floating gate. The insulating stud is disposed on the insulating layer. The first conductive layer is disposed over the substrate adjacent to the conductive spacer serving as a control gate. The first insulating spacer is disposed on the sidewall of the insulating stud to cover the first conductive layer. The drain region is formed in the substrate adjacent to the first conductive layer.
Abstract:
A method of fabricating a memory cell of self-aligned split gate flash memory first provides a substrate having an active area. A first gate insulating layer, a conductive layer and a buffer layer are formed within the active area. A portion of the buffer layer is removed to form a first opening. A buffer spacer is formed on the side walls of the first opening. A portion of the conductive layer and first gate insulating layer under the first opening are removed to form a second opening. The contact spacers, the source region and the contact plug are formed in the second opening in sequence. After the buffer spacers are removed, a third opening is formed. The bottom surface of the third opening and the top surface of the contact plug are oxidized to form the oxide layers. Another buffer spacers fill the third opening. The remaining buffer layer is removed to form the fourth opening. The conductive layer under the bottom of the fourth opening is removed, except the portion under the oxide layer, to form the floating gates. After the formation of a second gate insulating layer, the control gates and the control gate spacers are formed in sequence.