摘要:
A split gate EPROM cell and a method that includes a gate structure having a sidewall spacer of differential composition disposed about a floating gate which facilitates control of the spacer thickness during fabrication. Controlling the thickness of the spacer allows avoiding a reduction of the distance between the floating gate and the control gate as well as leakage of the charge from the floating gate.
摘要:
A split gate EPROM cell and a method that includes a gate structure having a sidewall spacer of differential composition disposed about a floating gate which facilitates control of the spacer thickness during fabrication. Controlling the thickness of the spacer allows avoiding a reduction of the distance between the floating gate and the control gate as well as leakage of the charge from the floating gate.
摘要:
An E2PROM or a flash memory cell having a sharp tip or thin wedge at one of its gates, e.g., the floating gate, for the erasure of electrical charges stored in the floating gate. A recess is formed between a first polysilicon gate and the substrate by removing portions of an insulating layer interposed between the first gate and the substrate. Another insulating layer, e.g., thermal oxide, is formed on the exposed portions of the first gate and the substrate, and partially fills the recess. A second polysilicon layer is formed on the thermal oxide and patterned to form a floating gate. The partially filled recess causes a sharp polysilicon tip or thin wedge to be formed as part of the floating gate. This sharp tip or thin wedge can generate a high electrical field that facilitates the removal of the stored electrical charges from the floating gate.
摘要:
A dual-gate cell structure with self-aligned gates. A polysilicon spacer forms a second gate (213) separated from a first gate (201), which is also polysilicon, by a dielectric layer (207). A drain region (219) and a source region (221) are formed next to the gates. In one embodiment, the second gate (213) acts as a floating gate in a flash cell. The floating gate may be programmed and erased by the application of appropriate voltage levels to the first gate (201), source (221), and/or drain (219). The self-aligned nature of the second gate (213) to the first gate (201) allows a very small dual-gate cell to be formed.
摘要:
A method of fabricating an interpoly dielectric layer and a gate oxide layer of a programmable memory device. This method allows a gate oxide layer and a top oxide layer of the interpoly dielectric layer to be formed simultaneously by two consecutive processes, and essentially comprises the following steps: (1) forming a bottom oxide and a nitride layer of the interpoly dielectric layer on a floating gate of the memory device; (2) defining a gate oxide growing region on the interpoly dielectric layer with a photoresist mask; (3) etching the nitride and bottom oxide layer over the area defined as the gate oxide growth region; (4) forming a first oxide layer on the gate oxide growth region and the nitride of the interpoly dielectric layer above the floating gate; and (5) forming a second oxide layer on the first oxide layer to serve simultaneously as part of the top oxide layer of the interpoly dielectric layer and as part of the gate oxide layer.
摘要:
The present disclosure provides a device in an integrated circuit. The device includes an active region in a semiconductor substrate; an isolation region adjacent the active region; a gate disposed on the active region and extending to the isolation region in a first direction; and a gate contact disposed within the isolation region, having a portion directly overlying and contacting the gate, and having a geometry horizontally extending to a first dimension in the first direction and a second dimension in a second direction approximately perpendicular to the first direction. The first dimension is greater than the second dimension.
摘要:
The present invention provides novel isolation regions (501, 215) in a flash memory integrated circuit device. The isolation regions (501, 215) are formed on a silicon substrate (201), which has a core memory region (e.g., flash memory cell region) and a high voltage region (e.g., high voltage MOS device region). A silicon dioxide layer (e.g., silicon dioxide, silicon oxynitride) (203) is defined overlying the substrate including both of the regions. A nitride mask layer (205) is formed overlying the silicon dioxide layer in the core memory region and the high voltage region. This nitride mask layer exposes (207) a first isolation region coupled to the high voltage region. The first isolation region includes a first isolation structure having a first thickness of silicon dioxide. A step of oxidizing an exposed second isolation region to form the second isolation structure (215) and simultaneously oxidizing the first isolation structure to a second thickness is included.
摘要:
A split gate flash memory unit comprises a silicon substrate; a first insulating layer formed on said silicon substrate; a first conductive layer formed on a part area of said first insulating layer; a second insulating layer formed on left and right sidewalls of said first conductive layer and on another part area of said first insulating layer; a third insulating layer formed on said first conductive layer. The third insulating layer is also formed on said second insulating layer located at said left and right side walls of the first conductive layer in order to reduce an asperity effect on left and right edges of said first conductive layer. A second conductive layer is formed on said second and third insulating layers for being isolated from said first conductive layer by a blocking function of said second and third insulating layer.
摘要:
A method for forming a structure of a split gate flash memory is provided. The method includes steps of: a) preparing a substrate having an oxide layer; b) forming a first conducting layer over the oxide layer; c) etching a portion of the first conducting layer to form a word line structure for the flash memory; d) forming a spacer layer over the word line structure to be a side-wall portion of a word-line protecting layer; e) oxidizing the word-line protecting layer to form a dielectric layer; and f) forming a floating gate layer over the dielectric layer.
摘要:
A split gate flash memory manufacturing process comprises the steps of: (a) providing a silicon substrate having a first insulating layer, and forming a first conductive layer on said first insulating layer, and forming a third insulating layer on said first conductive layer; (b) removing part of said third insulating layer and part of said first conductive layer to expose left and right sidewalls of said first conductive layer and part area of said first insulating layer; (c) performing an oxidation process to form a second insulating layer on left and right sidewalls of said first conductive layer and on said part area of said first insulating layer, wherein by a blocking function of the third insulating layer on said second insulating layer an asperity effect on left and right edges of said first conductive layer is reduced; and (d) forming a second conductive layer on said second and third insulating layers to form said split gate flash memory unit.