Abstract: Ferroelectric switching properties are severely degraded in a hydrogen ambient atmosphere. By controlling the polarity of the capacitors in a ferroelectric memory during the manufacturing process, the amount of degradation can be significantly reduced. After metalization of a ferroelectric memory wafer, all of the ferroelectric capacitors are poled in the same direction. The polarization vector is in a direction that helps to counteract hydrogen damage. A hydrogen gas anneal is subsequently performed to control underlying CMOS structures while maintaining ferroelectric electrical properties. The wafer is then passivated and tested.

Abstract: A plastic package assembly method suitable for ferroelectric-based integrated circuits includes a strict thermal budget that reduces the time at temperature for four key processing steps: die attach cures, die coat cures, molding cures, and marking cures. The plastic package assembly method uses low temperature mold and die coat materials, as well as low temperature curable inks or laser marking in order to minimize degradation of electrical performance, thus improving yields and reliability. The assembly method uses a snap cure die attach step, a die coat followed by a room temperature cure, and formation of the plastic package with room temperature curable molding compounds not requiring a post mold cure. Front and back marking of the plastic package is accomplished using either an infrared or ultraviolet curable ink followed by minimum cure time at elevated temperature, or by using laser marking.

Abstract: A ferroelectric capacitor includes a bottom electrode, a top electrode, and a ferroelectric layer located between the top and bottom electrodes that extends to completely encapsulate the top electrode, except for a contact hole to allow metalization of the top electrode. The total encapsulation of the top electrode reduces the sensitivity of the ferroelectric capacitor to hydrogen and thus improves electrical switching performance.

Abstract: The ferroelectric thin film is formed from a liquid composition by the sol-gel processing which has a large amount of polarization, remarkably improved retention and imprint characteristics as compared with a PZT, minute grains and fine film quality, homogeneous electrical properties, and low leakage currents and which is suited for nonvolatile memories. The ferroelectric thin film of the present invention comprising a metal oxide represented by the general formula: (Pbv Caw SrX LaY)(ZrZ Ti1−Z)O3, wherein 0.9≦V≦1.3, 0≦W≦0.1, 0≦X≦0.1, 0<Y≦0.1, 0<Z≦0.

Abstract: A ferroelectric capacitor stack for use with an integrated circuit transistor in a ferroelectric memory cell is fabricated by: forming a first dielectric layer over the integrated circuit transistor; forming a bottom electrode over the first dielectric layer, the bottom electrode having a hole located over a first source/drain of the integrated circuit transistor; forming a second dielectric layer over the first dielectric layer and bottom electrode; forming a hole in the second dielectric layer to provide access to the bottom electrode; forming a ferroelectric plug in the hole in the second dielectric layer; forming a top electrode over the second dielectric layer and ferroelectric plug; forming a third dielectric layer over the second dielectric layer and top electrode; forming a first via through the first, second, and third dielectric layers, and through the hole in the bottom electrode, the via having sufficient width to provide access to a lateral edge of the bottom electrode hole; forming a second via

Abstract: A memory cell layout for use in a 1T/1C ferroelectric memory array includes an access transistor having a gate coupled to a word line and a current path coupled between a bit line and an internal cell node, a shunt word line extending across the memory cell that is electrically isolated from the word line and the access transistor within the physical boundary of the memory cell, and a ferroelectric capacitor coupled between the internal cell node and a plate line.

Abstract: A ferroelectric capacitor stack for use with an integrated circuit transistor in a ferroelectric memory cell is fabricated by: forming a first dielectric layer over the integrated circuit transistor; forming a bottom electrode over the first dielectric layer, the bottom electrode having a hole located over a first source/drain of the integrated circuit transistor; forming a second dielectric layer over the first dielectric layer and bottom electrode; forming a hole in the second dielectric layer to provide access to the bottom electrode; forming a ferroelectric plug in the hole in the second dielectric layer; forming a top electrode over the second dielectric layer and ferroelectric plug; forming a third dielectric layer over the second dielectric layer and top electrode; forming a first via through the first, second, and third dielectric layers, and through the hole in the bottom electrode, the via having sufficient width to provide access to a lateral edge of the bottom electrode hole; forming a second via

Abstract: A ferroelectric capacitor includes a bottom electrode, a top electrode, an a ferroelectric layer located between the top and bottom electrodes that extends to completely encapsulate the top electrode, except for a contact hole to allow metalization of the top electrode. The total encapsulation of the top electrode reduces the sensitivity of the ferroelectric capacitor to hydrogen and thus improves electrical switching performance. The encapsulation technique can also be used to improve the performance of ferroelectric transistors and other devices.

Abstract: A non-volatile ferroelectric latch includes a sense amplifier having at least one input/output coupled to a bit-line node, a ferroelectric storage capacitor coupled between a plate-line node and the bit-line node, and a load element coupled to the bit-line node. The sense amplifier further includes a second input/output coupled to a second bit-line node and the latch further includes a second ferroelectric storage capacitor coupled between a second plate-line node and the second bit-sine node, and a second load element coupled to the second bit-line node. The load element includes a dynamic, switched ferroelectric capacitor a static, nonswitched ferroelectric capacitor, a linear capacitor, or even a resistive load.

Abstract: An RC equivalent delay circuit includes an input node, an output node, a feedback node, and an intermediate node; a first inverter having an input coupled to the input node and an output coupled to the intermediate node; a second inverter having an input coupled to the intermediate node and an output coupled to the feedback node; a third inverter having an input coupled to the feedback node and an output coupled to the output node; and one or two switches having a first input coupled to the input node, a second input coupled to the feedback node, and an output coupled to the intermediate node.

Abstract: A multi-layer ferroelectric thin film includes a nucleation layer, a bulk layer, and an optional cap layer. A thin nucleation layer of a specific composition is implemented on a bottom electrode to optimize ferroelectric crystal orientation and is markedly different from the composition required in the bulk of a ferroelectric film. The bulk film utilizes the established nucleation layer as a foundation for its crystalline growth. A multi-step deposition process is implemented to achieve a desired composition profile. This method also allows for an optional third composition adjustment near the upper surface of the film to ensure compatibility with an upper electrode interface and to compensate for interactions resulting from subsequent processing.

Abstract: A multi-layer ferroelectric thin film includes a nucleation layer, a bulk layer, and an optional cap layer. A thin nucleation layer of a specific composition is implemented on a bottom electrode to optimize ferroelectric crystal orientation and is markedly different from the composition required in the bulk of a ferroelectric film. The bulk film utilizes the established nucleation layer as a foundation for its crystalline growth. A multi-step deposition process is implemented to achieve a desired composition profile. This method also allows for an optional third composition adjustment near the upper surface of the film to ensure compatibility with an upper electrode interface and to compensate for interactions resulting from subsequent processing.

Abstract: A preferred state power-up latch circuit includes first and second cross-coupled P-channel transistors coupled to a first source of supply voltage, first and second cross-coupled N-channel transistors coupled to a second source of supply voltage, the transistors being coupled together to form a latch having an output node, in which at least one of the gate lengths is unequal to the other gates lengths in order to establish a preferred state upon power-up, and the gate width of all the transistors is equal.

Abstract: A ferroelectric capacitor includes a bottom electrode, a top electrode, and a ferroelectric layer located between the top and bottom electrodes that extends to completely encapsulate the top electrode, except for a contact hole to allow metalization of the top electrode. The total encapsulation of the top electrode reduces the sensitivity of the ferroelectric capacitor to hydrogen and thus improves electrical switching performance. The encapsulation technique can also be used to improve the performance of ferroelectric transistors and other devices.

Abstract: A memory cell layout for use in a 1T/1C ferroelectric memory array includes an access transistor having a gate coupled to a word line and a current path coupled between a bit line and an internal cell node, a shunt word line extending across the memory cell that is electrically isolated from the word line and the access transistor within the physical boundary of the memory cell, and a ferroelectric capacitor coupled between the internal cell node and a plate line.

Abstract: A test method for characterizing retention performance, both same state and opposite state performance, of ferroelectric capacitors includes the steps of writing an original complementary data state into first and second ferroelectric capacitors after the ferroelectric capacitors have been initialized into an initial valid data state. The first and second ferroelectric capacitors are then subjected to time and temperature stress. The original complementary data state from the first and second ferroelectric capacitors is then read, and same state charge (Q.sub.SS) information is collected. An opposite complementary data state is then written in the first and second capacitors. After a short time interval, possibly at an elevated temperature, the opposite complementary data state from the first and second ferroelectric capacitors is read to gather opposite state charge (Q.sub.OS) information. The original complementary data state is then written into the first and second ferroelectric capacitors.

Abstract: A method of driving a sense amplifier having at least one input/output node and at least one latch node the method includes the steps of initially setting the latch node to a first logic state such that the sense amplifier is disabled, adjusting the latch node voltage in one or more discrete levels, and finally setting the latch node to a second logic state such that the sense amplifier is enabled.

Abstract: A bootstrap circuit suitable for use in driving the word line of a FRAM.RTM. memory circuit is energized by a VDD power supply voltage. The bootstrap circuit includes a first N-channel MOS transistor wherein the source/drain forms the input of the circuit. A second N-channel MOS transistor is included wherein one of the source/drains receives a clock signal, and the other source/drain forms the output, which drives the word line. The gate of the second transistor is coupled to the other source/drain of the first transistor. The bootstrap circuit includes further circuitry for generating a voltage greater tan the VDD power supply voltage that is coupled to the gate of the first transistor. A capacitor or capacitor-connected transistor is coupled between the input and the gate of the first transistor, and a third transistor has one source/drain coupled to the gate of the first transistor, and the other source/drain receives a control signal, and the gate is coupled to the VDD power supply.

Abstract: A plate line segmentation scheme for a 1T/1C ferroelectric memory architecture includes an array of 1T/1C ferroelectric memory cells, word lines corresponding to each row of 1T/1C ferroelectric memory cells, and plate lines corresponding to each row of 1T/1C ferroelectric memory cells, wherein each plate line is divided into two or more equal plate line segments, only one of which is driven when a corresponding word line is selected.

Abstract: An iridium oxide local interconnect method for a ferroelectric memory cell includes the steps of forming a conductive layer that extends from a source/drain contact of the transistor proximate to an electrode contact of the ferroelectric capacitor and forming an iridium oxide local interconnect extending from the source/drain contact of the transistor to the electrode contact of the ferroelectric capacitor. The conductive layer is laterally terminated not less than one-half micron from the electrode contact of the ferroelectric capacitor. The conductive layer can include an upper iridium layer and a bottom titanium nitride layer, or can include a single layer of completely reacted titanium nitride. After the local interconnect is formed a top oxide layer is deposited. A late recovery anneal is then performed in oxygen at an elevated temperature to rejuvenate the electrical characteristics of the ferroelectric capacitor. Finally, a bit line contact is opened and metalized.