摘要:
A virtual ground memory array (VGA) is formed by a storage layer over a substrate with a conductive layer over the storage layer. The conductive layer is opened according to a patterned photoresist layer. The openings are implanted to form source/drain lines in the substrate, then filled with a layer of dielectric material. Chemical mechanical polishing (CMP) is then performed until the top of the conductive layer is exposed. This leaves dielectric spacers over the source/drain lines and conductive material between the dielectric spacers. Word lines are then formed over the conductive material and the dielectric spacers. As an alternative, instead of using a conductive layer, a sacrificial layer is used that is removed after the CMP step. After removing the sacrificial portions, the word lines are formed. In both cases, dielectric spacers reduce gate/drain capacitance and the distance from substrate to gate is held constant across the channel.
摘要:
A virtual ground memory array (VGA) is formed by a storage layer over a substrate with a conductive layer over the storage layer. The conductive layer is opened according to a patterned photoresist layer. The openings are implanted to form source/drain lines in the substrate, then filled with a layer of dielectric material. Chemical mechanical polishing (CMP) is then performed until the top of the conductive layer is exposed. This leaves dielectric spacers over the source/drain lines and conductive material between the dielectric spacers. Word lines are then formed over the conductive material and the dielectric spacers. As an alternative, instead of using a conductive layer, a sacrificial layer is used that is removed after the CMP step. After removing the sacrificial portions, the word lines are formed. In both cases, dielectric spacers reduce gate/drain capacitance and the distance from substrate to gate is held constant across the channel.
摘要:
A floating gate memory cell has a floating gate in which there are two floating gate layers. The top layer is etched to provide a contour in the top layer while leaving the lower layer unchanged. The control gate follows the contour of the floating gate to increase capacitance therebetween. The two layers of the floating gate can be polysilicon separated by a very thin etch stop layer. This etch stop layer is thick enough to provide an etch stop during a polysilicon etch but preferably thin enough to be electrically transparent. Electrons are able to easily move between the two layers. Thus the etch of the top layer does not extend into the lower layer but the first and second layer have the electrical effect for the purposes of a floating gate of being a continuous conductive layer.
摘要:
A semiconductor storage cell includes a first source/drain region underlying a first trench defined in a semiconductor layer. A second source/drain region underlies a second trench in the semiconductor layer. A first select gate in the first trench and a second select gate in the second trench are lined by a select gate dielectric. A charge storage stack overlies the select gates and a control gate overlies the stack. The DSEs may comprise discreet accumulations of polysilicon. An upper surface of the first and second select gates is lower than an upper surface of the first and second trenches. The control gate may be a continuous control gate traversing and running perpendicular to the select gates. The cell may include contacts to the semiconductor layer. The control gate may include a first control gate overlying the first select gate and a second control gate overlying the second select gate.
摘要:
An array of storage cells include a first source/drain region underlying a first trench defined in a semiconductor substrate and a second source/drain region underlying a second trench in the substrate. A charge storage stack lines each of the trenches where the charge storage stack includes a layer of discontinuous storage elements (DSEs). A control gate overlies the first trench. The control gate may run perpendicular to the trenches and traverse the first and second trenches. In another implementation, the control gate runs parallel with the trenches. The storage cell may include one or more diffusion regions occupying an upper surface of the substrate between the first and second trenches. The diffusion region may reside between first and second control gates that are parallel to the trenches. Alternatively, a pair of diffusion regions may occur on either side of a control gate that is perpendicular to the trenches.
摘要:
A process for forming an electronic device can include forming a first set of discontinuous storage elements over a primary surface of a substrate and forming a trench within the substrate. The process can also include forming a second set of discontinuous storage elements within the trench. The process can further include forming a first gate electrode within the trench, wherein a discontinuous storage element lies between the first gate electrode and a wall of the trench. The process can still further include removing a part of the second set of discontinuous storage elements and forming a second gate electrode over the first gate electrode. After forming the second gate electrode, substantially none of the second set of discontinuous storage elements lies along the wall of the trench at an elevation between an upper surface of the first gate electrode and the primary surface of the substrate.
摘要:
An electronic device can include a substrate having a trench that includes a wall and a bottom. The electronic device can also include a first set of discontinuous storage elements that overlie a primary surface of the substrate and a second set of discontinuous storage elements that lie within the trench. The electronic device can also include a first gate electrode, wherein substantially none of the discontinuous storage elements lies along the wall of the trench at an elevation between and upper surface of the first gate electrode and the primary surface of the substrate. The electronic device can also include a second gate electrode overlying the first gate electrode and the primary surface. In another embodiment, a conductive line can be electrically connected to one or more rows or columns of memory cells, and another conductive line can be more rows or more columns of memory cells.
摘要:
A semiconductor device (10) has a highly doped layer (26) having a first conductivity type uniformly implanted into the semiconductor substrate (20). An oxide-nitride-oxide structure (36, 38, 40) is formed over the semiconductor substrate (20). A halo region (46) having the first conductivity type is implanted at an angle in only a drain side of the oxide-nitride-oxide structure and extends under the oxide-nitride-oxide structure a predetermined distance from an edge of the oxide-nitride-oxide structure. A source (52) and drain (54) having a second conductivity type are implanted into the substrate (20). The resulting non-volatile memory cell provides a low natural threshold voltage to minimize threshold voltage drift during a read cycle. In addition, the use of the halo region (46) on the drain side allows a higher programming speed, and the highly doped layer (26) allows the use of a short channel device.
摘要:
A method of making a semiconductor device includes providing a first wafer and providing a second wafer having a first side and a second side, the second wafer including a semiconductor substrate, a storage layer, and a layer of gate material. The storage layer may be located between the semiconductor structure and the layer of the gate material and the storage layer may be located closer to the first side of the second wafer than the semiconductor structure. The method further includes boding the first side of the second wafer to the first wafer. The method further includes removing a first portion of the semiconductor structure to leave a layer of the semiconductor structure after the bonding. The method further includes forming a transistor having a channel region, wherein at least a portion of the channel region is formed from the layer of the semiconductor structure.
摘要:
An electronic device can include discontinuous storage elements that lie within a trench. In one embodiment, the electronic device can include a substrate having a trench that includes a wall and a bottom. The electronic device can also include a portion of discontinuous storage elements that lie within the trench. The electronic device can also include a first gate electrode, wherein at least one discontinuous storage element lies along the wall of the trench at an elevation between and upper surface of the first gate electrode and a primary surface of the substrate. The electronic device can also include a second gate electrode overlying the first gate electrode and the primary surface of the substrate. In another embodiment, a conductive line can be electrically connected to one or more rows or columns of memory cells, and another conductive line can be more rows or more columns of memory cells.