Abstract: In one embodiment, an EEPROM device having voltage limiting charge pumping circuitry includes charge-pumping circuitry that limits the voltage supplied to the high voltage transistors to levels below the breakdown field of the tunnel oxide layer. The EEPROM device includes a substrate having a programming region, a tunnel region, a sensing region, and a low voltage region. A first oxide layer having a first thickness overlies the tunnel region and the sensing region. A second oxide layer having a second thickness overlies the low voltage region. The first oxide thickness is greater than the second oxide thickness. A charge pumping circuit is coupled to the programming region and to the tunnel region. The charge pumping circuit impresses a voltage level across the first oxide layer that is below the field breakdown voltage of first oxide layer.

Abstract: A process for fabricating a semiconductor device having electrically isolated low voltage and high voltage substrate regions includes low voltage and high voltage trench isolation structures in which a deep portion of the high voltage isolation trench provides electrical isolation in the high voltage regions. The high voltage isolation trench structures include a shallow portion that can be simultaneously formed with the low voltage trench isolation structures. The deep portion of the high voltage isolation trench has a bottom surface and shares a continuous wall surface with the shallow portion that extends from the bottom surface to the principal surface of the substrate. A process for fabricating the device includes the formation of sidewall spacers to define a minimum isolation width between adjacent high voltage nodes.

Abstract: An EEPROM device exhibiting high saturation current and low signal propagation delay and a process for fabricating the device that includes the formation of refractory metal silicide regions in the source and the drain regions and the gate electrode of an MOS transistor within an EEPROM memory cell. A floating-gate protect layer is formed over the floating-gate electrode and a relatively thick cap oxide layer is formed to overlie the floating-gate protect layer and the source and drain regions and gate electrode of the MOS transistor. A doped oxide layer is formed to overlie the cap oxide layer. The cap oxide layer is formed to a thickness sufficient to create strain in the channel region of the MOS transistor, while not having a thickness that could cause poor data retention in the EEPROM memory cell.

Abstract: An EEPROM device having voltage limiting charge pumping circuitry includes charge pumping circuitry that limits the voltage supplied to the high voltage transistors to levels below the breakdown field of the tunnel oxide layer. The EEPROM device includes a substrate having a programming region, a tunnel region, a sensing region, and a low voltage region. A first oxide layer having a first thickness overlies the tunnel region and the sensing region. A second oxide layer having a second thickness overlies the low voltage region. The first oxide thickness is greater than the second oxide thickness. A charge pumping circuit is coupled to the programming region and to the tunnel region. The charge pumping circuit impresses a voltage level across the first oxide layer that is below the field breakdown voltage of first oxide layer. A process for fabricating the device is also provided.

Abstract: A semiconductor device having an EEPROM memory cell includes a substrate having a principal surface and an isolation region having an inner edge surface bounding the tunnel region at the principal surface. The isolation region forms a perimeter of the tunnel region. A capacitor plate overlies the tunnel region and substantially the entire perimeter of the tunnel region. A tunnel dielectric layer overlies the tunnel region and separates the capacitor plate from the tunnel dielectric layer. The edges of the capacitor plate are displaced away from the tunnel dielectric layer to avoid a loss of tunneling current as a result of edge degradation with repeated programming and erasing of the EEPROM memory device. A process for fabrication of the device is also provided.

Abstract: A device having electrically isolated low voltage and high voltage substrate regions includes low voltage and high voltage trench isolation structures in which a deep portion of the high voltage isolation trench provides electrical isolation in the high voltage regions. The high voltage isolation trench structures include a shallow portion that is simultaneously formed with the low voltage trench isolation structures. The deep portion of the high voltage isolation trench has a bottom surface and shares a continuous wall surface with the shallow portion that extends from the bottom surface to the principal surface of the substrate. A process for fabricating the device includes the use of a single resist pattern to simultaneously form the low voltage isolation trench structures and the shallow portion of the high voltage isolation structures.

Abstract: An EEPROM device and process for fabricating the device having a retrograde program junction region includes providing a semiconductor substrate having a principal surface and forming a program junction region in the semiconductor substrate. The program junction region is characterized by a doping concentration profile in which a maximum doping concentration is displaced away from the principal surface. The doping concentration profile can be obtained by forming a first portion of a tunnel dielectric layer on the principal surface, then introducing doping atoms into the program junction region, followed by forming a second portion of a tunnel dielectric layer. In another embodiment, the doping concentration profile in the program junction region is formed by two consecutive doping processes, in which either the same doping species is introduced at different energies, or a second doping process is carried out with a dopant having a different conductivity type than the first dopant.

Abstract: An EEPROM device having improved data retention and process for fabricating the device includes a two-step deposition process for the fabrication of an ILD layer overlying the high voltage elements of an EEPROM memory cell. The ILD layer is fabricated by first depositing an insulating layer on a high voltage device layer and thermally treating insulating layer. A second insulating layer is then deposited to overlie the first insulating layer. An EEPROM device in accordance with the invention includes a floating-gate transistor having a specified threshold voltage. A thermally-treated, boron-doped oxide layer overlies the floating-gate transistor and a second oxide layer overlies the thermally-treated, boron-doped oxide layer. The memory device exhibits data retention characteristics, such that upon subjecting the device to a baked temperature of at least about 250° C. for at least about 360 hours, the threshold voltage of the floating-gate transistor shifts by no more than about 100 mV.

Abstract: An improved method for fabricating a tunnel oxide window for use in an EEPROM memory cell is provided so as to produce better programming endurance. P-type lightly-doped drain regions are located at the polysilicon edges of the tunnel window. During the programming operation, the P-type lightly-doped drain regions are in contacting with the polysilicon edges. As a result, there is reduced or suppressed the tunneling current to the program junction region so as to improve the efficiency of programming.

Abstract: A shallow junction EEPROM device and process for fabricating the device includes the formation of a control-gate region and a tunnel region in a semiconductor substrate in which the control-gate region has a substantially higher total doping concentration than the tunnel region. To compensate for rate enhanced oxidation of the silicon surface overlying the control-gate region, nitrogen is selectively introduced into the control-gate region, such that the resulting dielectric layer thickness overlying the control-gate region is substantially the same as that overlying the tunnel region. The relatively high doping concentration of the control-gate region enables fabrication of an EEPROM device having high capacitance coupling, shallow junctions, and a relatively small capacitor area.

Abstract: A non-volatile memory cell at least partially formed in a semiconductor substrate, comprising a first avalanche injection element having a first active region of a first conductivity type and a second active region of a second conductivity type, separated by a channel region of said second conductivity type; a second avalanche injection element having a third active region of said second conductivity type and sharing said second active region with said first avalanche injection element, the second avalanche injection element having a channel region of said first conductivity type; and a common floating gate at least partially overlying said first and second avalanche injection elements. In a further embodiment, the first avalanche element has an N+/P junction, the second avalanche element has a P+/N junction, and the floating gate capacitively coupled to the first and second avalanche elements.

Abstract: An improved method for fabricating a tunnel oxide window for use in an EEPROM memory cell is provided so as to produce better programming endurance. A P+ implant is provided at the tunnel window edge. During the programming operation, the P+ contacted inversion layer is used instead of the program junction. As a result, there is eliminated the voltage drop in the program junction region so as to improve the efficiency of programming.

Abstract: An improved method of fabricating a non-volatile semiconductor device having a BPTEOS oxide film is provided. The present method utilizes the step of performing a RTA at a temperature of about 800° C. immediately after the deposition of the BPTEOS film so as to densify and stabilize the same. Then, a CMP step is performed so as to planarize the BPTEOS film.

Abstract: An improved method of fabricating a non-volatile semiconductor device having a BPTEOS oxide film is provided. The present method utilizes the step of performing a RTA at a temperature of about 800° C. immediately after the deposition of the BPTEOS film so as to densify and stabilize the same. Then, a CMP step is performed so as to planarize the BPTEOS film.

Abstract: An improved manufacturing process and an improved device made by the process for forming via interconnects between metal layers in a multilevel metallization structure substantially eliminates trench formation during via overetch and exploding vias during via fill. An insulating multilayer structure comprising a conformal oxide, a spin-on layer, and an etch stop layer for the via etch locally planarizes the region adjacent to metal lines before the ILD is deposited and vias are patterned and etched. Using this process, metal borders around vias can be reduced or eliminated, thereby increasing circuit packing density.

Abstract: This invention provides methods for reducing the mechanical stresses within dielectric layers filling the gaps in shallow trench isolation (STI) regions on semiconductor wafers. The methods include the sequential deposition of alternating layers of dielectric materials having tensile stress and compressive stress, respectively. The invention also provides methods for adjusting the residual stress in a dielectric film by controlling the relative thicknesses of the alternating layers of dielectric material to provide bilayers having minimal overall stress. Additionally, the invention provides semiconductor devices having the reduced stress dielectric materials within the shallow isolation trenches of the semiconductor wafer. The reduction in stress within and between trenches decreases defects in the shallow isolation materials and thereby decreases source-drain and trench-trench short circuiting.

Abstract: An improved method for fabricating a tunnel oxide window for use in an EEPROM memory cell is provided so as to produce better programming endurance. A P+ implant is provided at the tunnel window edge. During the programming operation, the P+ contacted inversion layer is used instead of the program junction. As a result, there is eliminated the voltage drop in the program junction region so as to improve the efficiency of programming.

Abstract: An improved EEPROM cell with a self-aligned tunneling window is provided which is fabricated by a standard STI process so as to produce a smaller layout size and a reduced cell height. The EEPROM cell includes a floating gate, a programmable junction region, and a tunneling oxide layer separating the programmable junction region and the floating gate. The length dimension of the floating gate is less than the length dimension of the tunneling window so that the tunneling window is overlapping the floating gate. The tunneling window is self-aligned by edges forming the length dimension of the floating gate so as to form a self-aligned tunneling window.

Abstract: A program element for a memory cell formed in a substrate. The element includes a well region of an opposite conductivity type as said substrate formed in the substrate; a first active region formed in the well and having the same conductivity type as said well; and a second active region formed in the well and having a conductivity type opposite to that of the well, and having a junction with said first active region. In a further aspect, the element is used in a memory cell. The memory cell may be implemented in an array of cells to perform a method of creating a reverse breakdown condition in an array of memory cells arranged in columns and rows in the array.

Abstract: A zero-power electrically erasable and programmable memory cell is implemented in CMOS (complementary metal oxide semiconductor) technology. A P-channel sense transistor has a source coupled to a first voltage generator, and an N-channel sense transistor has a source coupled to a second voltage generator. The drains of the P-channel and N-channel sense transistors are coupled together to form an output of the memory cell, and the gates of the P-channel and N-channel sense transistor are coupled together to form a floating gate of the memory cell. In an example embodiment of the present invention, each of the first and second voltage generators are variable voltage generators that apply a positive voltage at the respective source of each of the P-channel and N-channel sense transistors during the erase operation and/or that apply a ground or negative voltage at the respective source of each of the P-channel and N-channel sense transistors during the program operation.