Abstract: A nonvolatile EEPROM cell having a double poly arrangement provides stored data without sense amplifiers, thereby reducing power requirements. The EEPROM cell has a floating gate in a first poly layer, and a control gate overlapping the floating gate in a second poly layer. This configuration allows for an area-efficient layout that is easily shrinkable as compared to prior art memory cells. In addition, stacking the control and floating gates results in higher capacitive coupling. The EEPROM cell also includes an access gate, a tunnel capacitor, and at least one inverter. In some embodiments, the EEPROM cell can be advantageously used to configure programmable logic without need for a conloading step.

Abstract: Polysilicon or other material is directionally trimmed using two layers of photoresist and a photoresist etching process, such as ashing. A first layer of photoresist is patterned on a wafer. Portions of the first patterned photoresist are covered with a second layer of photoresist. The photoresist is trimmed to reduce the size of the exposed portions of the first patterned photoresist without reducing the size of the covered portions of the first patterned photoresist. The second layer of photoresist is removed. The selectively etched patterned first layer of photoresist is used as a process mask to define a structure in the underlying material. In a particular embodiment, the second photoresist covers endcap portions of gate photoresist. Directional trimming reduces the width of a polysilicon gate structure (i.e. gate length) over an active area of an FET, without reducing the length of original first patterned photoresist.

Abstract: An EEPROM memory cell array architecture (50) that substantially eliminates leakage current to allow for reading memory cells (20) in a memory cell array of, for example, a CPLD at lower voltages than are possible with prior art architectures, thereby facilitating development of low voltage applications. This is accomplished by associating each wordline of the memory cell array with a ground transistor (26). On one embodiment, the ground transistor (26) can be a high voltage transistor, in which case the same high voltage control signal can control both the ground transistor (26) and the memory cell=s read transistor (32). In another embodiment, the ground transistor (26) is a low voltage transistor controlled by a separate low voltage control signal.

Abstract: A nonvolatile memory cell which is highly scalable includes a cell formed in a triple well. A pair of sources for a pair of cells on adjacent word lines each acts as the emitter of a lateral bipolar transistor. The lateral bipolar transistor of one cell operates as a charge injector for the other cell. The charge injector provides carriers for substrate hot carrier injection onto a floating gate.

Abstract: A nonvolatile memory cell which is highly scalable includes a cell formed in a triple well. A select transistor can have a source which also acts as the emitter of a lateral bipolar transistor. The lateral bipolar transistor operates as a charge injector. The charge injector provides electrons for substrate hot electron injection of electrons onto the floating gate for programming. The cell depletion/inversion region may be extended by forming a capacitor as an extension of the control gate over the substrate between the source and channel of said sense transistor.

Abstract: A nonvolatile memory cell which is highly scalable includes a cell formed in a triple well. A pair of sources for a pair of cells on adjacent word lines each acts as the emitter of a lateral bipolar transistor. The lateral bipolar transistor of one cell operates as a charge injector for the other cell. The charge injector provides carriers for substrate hot carrier injection onto a floating gate.

Abstract: A nonvolatile memory cell which is highly scalable includes a cell formed in a triple well. A select transistor can have a source which also acts as the emitter of a lateral bipolar transistor. The lateral bipolar transistor operates as a charge injector. The charge injector provides electrons for substrate hot electron injection of electrons onto the floating gate for programming. The cell depletion/inversion region may be extended by forming a capacitor as an extension of the control gate over the substrate between the source and channel of said sense transistor.

Abstract: A nonvolatile memory cell which is highly scalable includes a cell formed in a triple well. A pair of sources for a pair of cells on adjacent word lines each acts as the emitter of a lateral bipolar transistor. The lateral bipolar transistor of one cell operates as a charge injector for the other cell. The charge injector provides carriers for substrate hot carrier injection onto a floating gate.

Abstract: A gate stack formation process directed toward reducing floating gate oxidation which influences tunnel oxide thickness and, therefore, discharge speed. On a substrate upon which is formed an oxide layer, a first polysilicon layer, a dielectric layer, and a second polysilicon layer, only the second polysilicon layer and dielectric layer are etched. Source and drain regions are implanted through the first polysilicon layer. Subsequently, the first polysilicon layer is etched to form the full gate stack.

Abstract: A process for discharging a floating gate semiconductor device formed in a semiconductor substrate, the device having a first active region, a second active region, a charge holding region, and a channel between the first and second active regions, the channel having a length defined by a distance below the charge holding region between the first and second active regions. The process comprises the steps of: applying a first positive voltage of about 4-8 volts to the first active region; applying a second voltage in the range of about 0.5-3 volts to the second active region; applying a third voltage in the range of minus 8 volts to the charge holding region; and coupling the substrate to ground. The first active region may comprise either a source or a drain region of a MOSFET, and the second active region may comprise a source region or a drain region of a MOSFET.