Abstract:
Nonvolatile memory wordlines (160) are formed as sidewall spacers on sidewalls of control gate structures (280). Each control gate structure may contain floating and control gates (120, 140), or some other elements. Pedestals (340) are formed adjacent to the control gate structures before the conductive layer (160) for the wordlines is deposited. The pedestals will facilitate formation of the contact openings (330.1) that will be etched in an overlying dielectric (310) to form contacts to the wordlines. The pedestals can be dummy structures. A pedestal can physically contact two wordlines.
Abstract:
A method of fabricating a recess channel transistor is provided. First, a hard mask is formed on a doped-semiconductor layer and a substrate. The doped-semiconductor layer and the substrate are etched to form a trench and define a source/drain in the doped-semiconductor layer. An implantation process is performed with a tilt angle on sidewalls of the trench to form an implant area. A thermal oxidation process is performed to form an oxide layer. The oxide layer comprises a first thickness on the source/drain in the sidewalls of the trench and a second thickness on the other portion in the sidewalls of the trench.
Abstract:
A method for preparing a capacitor structure comprises forming an opening in a dielectric structure, and forming a cylindrical capacitor including a first conductive layer on the sidewall of the opening, a first dielectric layer on the surface of the first conductive layer, and a second conductive layer on the surface of the first dielectric layer. A top portion of the first conductive layer is selectively removed, and a predetermined portion of the dielectric structure is removed. A second dielectric layer covering the cylindrical capacitor and the dielectric structure is then formed to electrically separate the first conductive layer from the second conductive layer. Subsequently, a portion of the second dielectric layer is removed from the top surface of the second conductive layer, and a third conductive layer is formed on the second dielectric layer and the top surface of the second conductive layer.
Abstract:
In a memory cell (110) having multiple floating gates (160), the select gate (140) is formed before the floating gates. In some embodiments, the memory cell also has control gates (170) formed after the select gate. Substrate isolation regions (220) are formed in a semiconductor substrate (120). The substrate isolation regions protrude above the substrate. Then select gate lines (140) are formed. Then a floating gate layer (160) is deposited. The floating gate layer is etched until the substrate isolation regions are exposed. A dielectric (164) is formed over the floating gate layer, and a control gate layer (170) is deposited. The control gate layer protrudes upward over each select gate line. These the control gates and the floating gates are defined independently of photolithographic alignment. In another aspect, a nonvolatile memory cell has at least two conductive floating gates (160). A dielectric layer (164) overlying the floating gate has a continuous feature that overlies the floating gate and also overlays a sidewall of the select gate (140). Each control gate (160) overlies the continuous feature of the dielectric layer and also overlies the floating gate. In another aspect, substrate isolation regions (220) are formed in a semiconductor substrate. Select gate lines cross over the substrate isolation regions. Each select gate line has a planar top surface, but its bottom surface goes up and down over the substrate isolation regions. Other features are also provided.
Abstract:
A NVM including a substrate, a control gate layer, a charge storage layer, a tunneling layer, a charge barrier layer, a gate dielectric layer and a first doping region is described. The control gate layer is disposed in a first trench of the substrate; the charge storage layer is disposed between the sidewall of the first trench and the control gate layer; the tunneling layer is disposed between the sidewall of the first trench and the charge storage layer; the charge barrier layer is disposed between the charge storage layer and the control gate layer; the gate dielectric layer is disposed between the bottom of the first trench and the control gate layer; and the first doping region is disposed in the substrate at one side of the control gate layer.
Abstract:
An equalization circuit for a pair of resistive-capacitive data lines includes primary and secondary equalization circuits attached at both ends of the data line pair. A primary equalization circuit at one end of the data line pair receives a primary control signal, and a secondary equalization circuit at the other end of the data line pair receives a secondary control signal, which is different than the primary control signal. The equalization devices in the primary equalization circuit are attached near the read and write amplifiers and operate normally since all the information is available as to whether or not the corresponding data line pair should be equalized. The additional equalization devices in the secondary equalization circuit placed at the other end of the data line pair receive a simpler control signal that lacks the information as to whether or not any particular data line pair is being equalized.
Abstract:
The present invention relates to a semiconductor device comprising at least one gate located in each of a memory array area and a periphery circuit area of a substrate, respectively, wherein the pattern density in the memory array area is higher than that in the periphery circuit area. The semiconductor device also comprises a barrier layer, which is located in the memory array area and the periphery circuit area, an undoped oxide barrier, which is located on the barrier layer in the periphery circuit area, and a boron-containing silicate glass, which is located on the barrier layer in the memory array area and on the undoped oxide barrier in the periphery circuit area.
Abstract:
A gate dielectric (150) for a gate (160) is formed by thermal oxidation simultaneously with as a dielectric on a surface of another gate (140). The dielectric thickness on the other gate is controlled by the dopant concentration in the other gate. The gates may be gates of different MOS transistors, or a select gate and a floating gate of a memory cell. Other features are also provided.
Abstract:
In a memory cell (110) having multiple floating gates (160), the select gate (140) is formed before the floating gates. In some embodiments, the memory cell also has control gates (170) formed after the select gate. Substrate isolation regions (220) are formed in a semiconductor substrate (120). The substrate isolation regions protrude above the substrate. Then select gate lines (140) are formed. Then a floating gate layer (160) is deposited. The floating gate layer is etched until the substrate isolation regions are exposed. A dielectric (164) is formed over the floating gate layer, and a control gate layer (170) is deposited. The control gate layer protrudes upward over each select gate line. These the control gates and the floating gates are defined independently of photolithographic alignment. In another aspect, a nonvolatile memory cell has at least two conductive floating gates (160). A dielectric layer (164) overlying the floating gate has a continuous feature that overlies the floating gate and also overlays a sidewall of the select gate (140). Each control gate (160) overlies the continuous feature of the dielectric layer and also overlies the floating gate. In another aspect, substrate isolation regions (220) are formed in a semiconductor substrate. Select gate lines cross over the substrate isolation regions. Each select gate line has a planar top surface, but its bottom surface goes up and down over the substrate isolation regions. Other features are also provided.