Abstract: A bistable non-volatile latch circuit adapted to store a non-volatile binary data state during a program operation, and to assume one of two stable states in response to a power up operation that correspond uniquely to the data state has first and second circuit sections. The first circuit section has a first non-volatile current path with means to set the impedance of the first current path in a non-volatile manner. A first end of the first current path is connected to provide a logic output signal, which represents a binary logic state depending on a voltage applied to the a first signal input node. The set/reset signal to the first current path varies between at least the power source voltage and a program voltage that is negative with respect to the power source voltage. A second circuit section generates an output voltage on a second output node that represents a binary logic state opposite from the output states of the first circuit section.

Abstract: A non-volatile memory cell array using only a single level of polysilicon and a single level of metal has programmable single transistor memory cells on a semiconductor substrate of a first conductivity type, a well of a second conductivity type in the substrate, parallel bitlines oriented in a first direction, and reference line segments oriented in the first direction. Each reference line is paired with one of each bitline. The array also has parallel word lines oriented in a second direction to form an array of intersections with the pairs of bitline/reference line pairs, and a rewriteable single transistor memory cell at each intersection point.

Abstract: A method and structure for preventing over erasure in non-volatile memory cells uses simultaneous erase and program current injections which offset one another. These currents come from two separate injection points within the non-volatile memory transistor and are dominant at different points during the erase operation. The first occurring current erases the non-volatile device and the second prevents over erasure.

Abstract: A semiconductor integrated circuit to determine a passage of time that may include a time during which no electrical power is supplied to the circuit is disclosed. The circuit has a timing device that includes a memory storage dielectric material for trapping charge carriers and releasing the trapped charge carriers in a known manner over time. The timing device has an electrical parameter that is relatable to an electric field created by the trapped charge carriers. A charge injection circuit is provided for selectively injecting charge carriers into the memory storage dielectric material to create an initialized state, and a time reader circuit determines when the electrical parameter has reached a predetermined value that corresponds to a passage of a predetermined time. Preferably the timing device is an insulated gate field effect transistor in which the memory storage dielectric material is a dielectric material, such as SONOS or SNOS, between the gate and channel overlying at least the channel area.

Abstract: A transistor structure (10), memory array (150) using the transistor structure, and method for making it are presented. The memory array (150), on a semiconductor substrate (152), contains a plurality of substantially parallel bit lines (154,155). A plurality of channel regions in the substrate (152) are bounded in one direction by a sets of bit line pairs (154,155). A conductive field shield layer (160), over a first insulation layer (156), is patterned to provide electrical regions over the channel regions between the first alternate sets of the bit lines (154,155) to form isolation transistor structures when biased with respect to the substrate (152). The field shield layer (160) is patterned to expose the channel regions of the memory transistors (151, . . . , 151'") between second alternate sets of the bit lines (155,154). A second insulating layer (163) is formed over the field shield layer (160).

Abstract: An N-channel SNOS or SONOS type memory array (100) has programmable states with a negative, depletion mode threshold lower in magnitude than the supply voltage V.sub.CC when erased and a positive threshold when programmed. During reading, the supply voltage V.sub.CC is applied to the drain (16), while a positive voltage V.sub.R less than V.sub.CC -V.sub.ds,sat is applied to the source (14), where V.sub.ds,sat is the saturation voltage of the device. A reference voltage may also be applied to the substrate (11) during a read operation. Selected devices have V.sub.R applied to the gate (12), while inhibited devices have ground or the substrate potential V.sub.SS applied to the gate (12).

Abstract: A transistor structure (10), memory array (150) using the transistor structure, and method for making it are presented. The memory array (150), on a semiconductor substrate (152), contains a plurality of substantially parallel bit lines (154,155). A plurality of channel regions in the substrate (152) are bounded in one direction by a sets of bit line pairs (154,155). A conductive field shield layer (160), over a first insulation layer (156), is patterned to provide electrical regions over the channel regions between the first alternate sets of the bit lines (154,155) to form isolation transistor structures when biased with respect to the substrate (152). The field shield layer (160) is patterned to expose the channel regions of the memory transistors (151, . . . , 151'") between second alternate sets of the bit lines (155,154). A second insulating layer (163) is formed over the field shield layer (160).

Abstract: A semiconductor memory array having a plurality of rows of memory cells, a word line, which extends into at least two memory blocks, to carry drive signals, such as read select and deselect signals, erase select and deselect signals, and program select and deselect signals for selective delivery to a subword line. Two pairs of subword lines and associated drivers are arranged with each pair selectively connectible to a portion of the word line within the block containing the subword line pair and to an associated set of memory cells. Each subword line driver selectively delivers drive signals from the word line to a respective, selected one of the subword lines. The subword lines and their drivers are arranged to extend from opposite sides into the block with which the subword line pairs are associated to reduce the layout size necessary, and to enable fewer word line drivers to be needed for a particular layout pitch.