A memory cell disposed on a substrate has a first gate structure and a second gate structure. The memory cell includes a first heavily doped region adjacent to an outer side of the first gate structure. Further, a first lightly doped drain (LDD) region with a first type dopant is between the first heavily doped region and the outer side of the first gate structure. A pocket doped region with a second type dopant is overlapping with the first LDD region. The second type dopant is opposite to the first type dopant in conductive type. A second heavily doped region is adjacent to an outer side of the second gate structure, opposite to the first heavily doped region. A second LDD region with the first type dopant is disposed between the first gate structure and the second gate structure.

In the memory structure, a pair of gate stack structures is on a first dielectric layer and separated from each other. Each of the gate stack structures includes a word line and a second dielectric layer. A third dielectric layer is on the sidewall of the gate stack structures. A pair of floating gates is between the gate stack structures. Each of the floating gates is on the third dielectric layer on the sidewall of the corresponding gate stack structure. The top surface of the floating gates is not higher than the that of the second dielectric layer. A fourth dielectric layer covers the first and third dielectric layers, and the floating gates. A control gate is on the fourth dielectric layer between the floating gates. A doped region is in the substrate beside the gate stack structures. An erase gate is above the control gate and the floating gates.

A method is provided for fabricating a semiconductor memory device. The method includes providing a substrate and forming a stacked layer on the substrate, where the stacked layer includes a tunneling dielectric layer and a floating gate layer sequentially formed on the substrate. The method also includes forming a plurality of stacked structures by etching the stacked layer and the substrate, where the spacing between the adjacent stacked structures forms a plurality of parallel first trenches. In addition, the method includes forming a plurality of second trenches and forming a plurality of third trenches. Moreover, the method includes forming a second dielectric layer on the floating gate layer and the side wall and bottom of the third trenches and forming a control gate layer on the second dielectric layer. Further, the method includes forming a plurality of fourth trenches and removing the sacrificial layer along the fourth trenches.

An object is to provide a semiconductor device with a novel structure in which stored data can be held even when power is not supplied and there is no limit on the number of write operations. The semiconductor device includes a first memory cell including a first transistor and a second transistor, a second memory cell including a third transistor and a fourth transistor, and a driver circuit. The first transistor and the second transistor overlap at least partly with each other. The third transistor and the fourth transistor overlap at least partly with each other. The second memory cell is provided over the first memory cell. The first transistor includes a first semiconductor material. The second transistor, the third transistor, and the fourth transistor include a second semiconductor material.

A memory device includes an N-channel transistor and a P-channel transistor. A word line is electrically connected to a drain terminal of the N-channel transistor, and a source terminal of the P-channel transistor. A first bit line is electrically connected to a source terminal of the N-channel transistor. A second bit line is electrically connected to a drain terminal of the P-channel transistor. Gate terminals of the N-channel transistor and the P-channel transistor are electrically connected and floating.

The present invention provides a flash cell structure and a method of fabricating the same. The flash cell structure includes a semiconductor substrate, a stacked gate structure disposed on the semiconductor substrate, a first doped region disposed in the semiconductor substrate at a side of the stacked gate structure, a first dielectric layer, a second dielectric layer, and an erase gate. The stacked gate structure includes a floating gate insulated from the semiconductor substrate and a control gate disposed on the floating gate and insulated from the floating gate. The first dielectric layer is disposed on a sidewall of the floating gate. The second dielectric layer is disposed on the first doped region. A thickness of the first dielectric layer is less than a thickness of the second dielectric layer.

A method of forming a memory device that includes forming a sacrificial gate on a surface of a first source/drain region, and forming a channel opening through the sacrificial gate. The method may further include forming an epitaxial channel region is formed in the channel opening that is in situ doped to have an opposite conductivity type as the first of the source/drain region. A second source/drain region is formed on a portion of the epitaxial channel region opposite the portion of the epitaxial channel region that the first source/drain region is present on, wherein the second source/drain region has a same conductivity type as the conductivity type of the first source/drain region. A memory gate structure including a floating gate and a control gate is substituted for the sacrificial gate.

The present invention provides a semiconductor device that has a shorter distance between the bit lines and easily achieves higher storage capacity and density. The semiconductor device includes: first bit lines and an insulating layer that is provided between the first bit lines and in a groove. First faces of the first bit lines are aligned on a first line and second faces of the first bit lines are aligned on a second line. A first face of the insulating layer is disposed at a third line that is a first distance from the first line in a first direction and a second face of the insulating layer is disposed at a fourth line that is a second distance from the second line in a second direction.

Some embodiments of the present disclosure relate to a memory device, which includes a floating gate formed over a channel region of a substrate, and a control gate formed over the floating gate. First and second spacers are formed along sidewalls of the control gate, and extend over outer edges of the floating gate to form a non-uniform overhang, which can induce a wide distribution of erase speeds of the memory device. To improve the erase speed distribution, an etching process is performed on the first and second spacers prior to erase gate formation. The etching process removes the overhang of the first and second spacers at an interface between a bottom region of the first and second spacers and a top region of the floating gate to form a planar surface at the interface, and improves the erase speed distribution of the memory device.

A cross-point memory array includes a plurality of variable resistance memory cell pillars. Adjacent memory cell pillars are separated by a partially filled gap that includes a buried void. In addition, adjacent memory cell pillars include storage material elements that are at least partially interposed by the buried void.