摘要:
An electrical shield is provided in a non-volatile memory (NVM) cell structure to protect the cell's floating gate from any influence resulting from charge redistribution in the vicinity of the floating gate during a programming operation. The shield may be created from the second polysilicon layer or other conductive material covering the floating gate. The shield may be grounded. Alternately, it may be connected to the cell's control gate electrode resulting in better coupling between the floating gate and the control gate. It is not necessary that the shield cover the floating gate completely, the necessary protective effect is achieved if the coupling to the dielectric layers surrounding the floating gate is reduced.
摘要:
In an EEPROM array the cells are pre-charged or pre-erased so that they will respond uniformly to the same read voltage level. By clearly defining the threshold voltage for the cells in their erased states and in their programmed states, it is possible to define more than one read voltage and thus provide cells that an store multiple values and even analog values.
摘要:
The snapback characteristics of the parasitic NPN structure inside an NMOS device are used to write and store information in the device by periodically triggering the device from the high impedance state to the low impedance state using the self turn-on characteristics of the device under elevated voltage. To minimize power consumption, and thus overheating, in the “on” state, a pulsed mode operation is combined with dV/dt triggering powering the device at a constant Vdd pulse amplitude.
摘要:
In a high voltage ESD protection solution, a plurality of DIACs are connected together to define a cascaded structure with isolation regions provided to prevent n-well and p-well punch through. An p-ring surrounds the DIACs and provides a ground for the substrate in which the DIACs are formed.
摘要:
In a method and structure for a high voltage LDMOS with reduced hot carrier degradation, the thick field oxide is eliminated and a reduced surface field achieved instead by including adjacent p+ and n+ regions in the drain well and shorting these regions to each other, or by including a p+ region in the drain well and biasing it to a positive voltage relative to the source voltage.
摘要:
In a multiple input ESD protection structure, the inputs are isolated from the substrate by highly doped regions of opposite polarity to the input regions. Dual polarity is achieved by providing a symmetrical structure with n+ and p+ regions forming each dual polarity input. The inputs are formed in a p-well which, in turn, is formed in a n-well. Each dual polarity input is isolated by a PBL under the p-well, and a NISO underneath the n-well. An isolation ring separates and surrounds the inputs. The isolation ring comprises a p+ ring or a p+ region, n+ region, and p+ region formed into adjacent rings.
摘要:
The turn on time of an electrostatic discharge (ESD) structure, such as a silicon controlled rectifier (SCR), a low-voltage triggering SCR (LVTSCR), and a bipolar SCR (BSCR), is reduced by turning on the structure in two steps: a first step that locally turns on the pnp and npn transistors, and a second step that, over time, fully turns on the structure.
摘要:
In a triggering ESD protection structure, the triggering voltage is reduced by introducing one or more corners or spikes into the p-n breakdown junction. This may be done by providing a polygate with a zig-zag pattern to define triangular corners in the drain or anode of the structure.
摘要:
An ESD protection structure includes a semiconductor substrate of a first conductivity type, and first and second well regions of a second conductivity type disposed in the substrate. The first and second well regions are separated by a gap region of the substrate. Also included are first and second floating regions (of the second conductivity type) disposed in the first and second well regions adjacent to the gap region, respectively. The ESD protection structure also includes first and second contact regions of the first conductivity type disposed on the first and second well regions, respectively, and spaced apart from the first and second floating regions, respectively. The ESD protection structure also includes first and second contact regions of the second conductivity type disposed on the first and second well regions, respectively, and spaced apart from the first and second floating regions, respectively.
摘要:
When a high-voltage, such as from an ESD pulse, is placed across a silicon controlled rectifier, which includes an NPN transistor and a PNP transistor that is connected to the NPN transistor, the likelihood of punch through occurring between two regions of the rectifier is substantially reduced by forming the collector of the NPN transistor between the emitter and collector of the PNP transistor.