摘要:
A flash memory cell in the form of a transistor capable of storing multi-bit binary data is disclosed. A pair of floating gates are provided beneath a control gate. The control gate is connected to a word line while source and drain regions are connected to respective digit lines. The floating gates are separately charged and read out by controlling voltages applied to the word line and digit lines. The read out charges are decoded into a multi-bit binary value. Methods of fabricating the memory cell and operating it are also disclosed.
摘要:
The invention encompasses integrated circuitry which includes a semiconductive material substrate and a first field effect transistor supported by the substrate. The first field effect transistor comprises a first transistor gate assembly which includes a first layer of conductively doped semiconductive material and only one layer of conductive nitride. The integrated circuitry further comprises a second field effect transistor supported by the substrate. The second field effect transistor comprises a second transistor gate assembly which includes a second layer of conductively doped semiconductor material and at least two layers of conductive nitride. The invention also encompasses a field effect transistor assembly which includes a channel region and an insulative material along the channel region. The transistor assembly further includes a gate stack proximate the channel region. The gate stack includes a first conductive nitride layer separated from the channel region by the insulative material. The stack further includes a conductively doped semiconductive material proximate the first conductive nitride layer, and a second conductive nitride layer separated from the first conductive nitride layer by the conductively doped semiconductive material. Additionally, the invention encompasses methods of forming field effect transistors, and methods of forming integrated circuitry.
摘要:
The present invention relates to the formation of multiple gettering structures within a semiconductive substrate by ion implantation through recesses in the semiconductive substrate. A preferred embodiment of the present invention includes forming the recesses by using a reactive anisotropic etching medium, followed by implanting a gettering material. The gettering material is implanted by changing the gettering material for the reactive anisotropic etching medium. An advantage of the method of the present invention is that gettering structures are formed without the cost of an extra masking procedure and without the expense of MeV implantation equipment and procedures. As a result, metallic contaminants will not move as freely through the semiconductive substrate in the region of an active area proximal to the gettering structures. Following implantation and formation of the gettering structures, thermal processing may be carried out in order to induce lateral spread or widening of each of the gettering structures. In some embodiments, it may be desirable that each gettering structure substantially contact an adjacent gettering structure, which may be accomplished by directional ion implantation. In another embodiment of the present invention, a dual implantation is carried out. The shallow implantation migrates during thermal processing to fill crystal originated particles or pits (COPs) within the semiconductive substrate.
摘要:
An improved storage node junction between a doped active area in a semiconductor substrate and an overlying layer of polysilicon, such as the storage node junction in a DRAM memory cell. The area and perimeter of the storage node junction is significantly reduced and the junction is moved away from the adjacent isolation structure. An exemplary semiconductor device incorporating the new junction includes a storage node junction between a conductive polysilicon layer and an active area on a semiconductor substrate, the substrate having been subjected to LOCOS steps to create active areas bounded by a region of field oxide. An insulated gate electrode is formed over an anive area on the substrate, which has been doped to a first conductivity type. A contact region comprising a portion of the active area extends laterally between one side of the gate electrode and the field oxide region. The contact region has a first segment adjacent to the gate electrode and a second segment interposed between the first segment and the field oxide region. The first segment is thereby isolated from the field oxide region by the second segment. The first segment is doped to a second conductivity type. A layer of storage polysilicon is formed in electrical contact with the first segment of the contact region but not the second segment of the contact region. The storage polysilicon is isolated from the field oxide through an insulating layer interposed between the storage polysilicon and the second segment of the contact region.
摘要:
A vertically oriented diode for use in delivering current to a multi-state memory element in a memory cell. A vertical diode may be disposed in a diode container extending downwardly from a top of a silicon or oxide layer, and may be formed of a combination of silicon and/or metal layers disposed proximate to inner surfaces of a diode container. A multi-state memory element may be formed of a multi-state material, such as a chalcogenide, above a diode to complete a memory cell.
摘要:
At least both a rapid thermal etch step and a rapid thermal oxidation step are performed on a semiconductor substrate in situ in a rapid thermal processor. A method including an oxidation step followed by an etch step may be used to remove contamination and damage from a substrate. A method including a first etch step followed by an oxidation step and a second etch step may likewise be used to remove contamination and damage, and a final oxidation step may optionally be included to grow an oxide film. A method including an etch step followed by an oxidation step may also be used to grow an oxide film. Repeated alternate in situ oxidation and etch steps may be used until a desired removal of contamination or silicon damage is accomplished.
摘要:
A memory device wherein a diode is serially connected to a programmable resistor and is in electrical communication with a buried digit line. An electrically conductive plug is electrically interposed between the digit line and a strapping layer, thereby creating a double metal scheme wherein the strapping layer is a second metal layer overlying metal wordlines. In a method of a first embodiment the strapping material is electrically connected to the digit line through a planar landing pad overlying the conductive plug. An insulative material is sloped to the planar landing pad in order to provide a surface conducive to the formation of the strapping material. In a method of a second embodiment diodes are formed, each having a maximum width equal to f, which is equal to the minimum photolithographic limit of the photolithographic equipment being used, and distanced one from the other along a length of the digit line by a maximum distance equal to f; at least portions of the diodes are masked; at least a portion of an insulative material interposed between two diodes is removed to expose the buried digit line; and the conductive plug is formed in contact with the exposed portion of the buried digit line. After the formation of a programmable resistor in series with the diode a wordline is formed in electrical communication with each of the programmable resistors, and an insulative layer is formed overlying each wordline. Next an insulative spacer layer is deposited and etched to expose the conductive plug. The strapping layer is then formed overlying and in contact with the conductive plug.
摘要:
A flash memory cell in the form of a transistor capable of storing multi-bit binary data is disclosed. A pair of floating gates are provided beneath a control gate. The control gate is connected to a word line while active doped regions (source and drain regions) are connected to respective digit lines. The floating gates are separately charged and read out by controlling voltages applied to the word line and digit lines. The read out charges are decoded into a multi-bit binary value. One or both of the floating gates has a side insulator which connects through a conductor to an associated active doped region thereby forming a capacitor across the side insulator between the floating gate. This capacitor and active region facilitates operation of the transistor as a flash memory cell. Methods of fabricating the memory cell and operating it are also disclosed.
摘要:
The present invention relates to a well-drive process in which the process of well driving is carried out simultaneously with a densification cycle. The inventive method is particularly applicable to isolation trenches having widths at or below about 0.2 microns. The inventive method may be applied to other semiconductive structures of varying geometries.
摘要:
A method of forming a connection is comprised of the steps of depositing a lower conductor. A dielectric layer is deposited on the lower conductor, with the dielectric layer having a lower surface adjacent to the lower conductor, and having an upper surface. An opening extending between the upper surface and the lower surface of the dielectric layer is formed. A conductive plug is deposited within the opening, with the plug having an upper surface proximate the upper surface of the dielectric layer. The upper surface has an edge where the upper surface of the plug is adjacent to the dielectric layer. A recess is formed proximate to the edge of the upper surface of the plug, the recess extending into both the plug and the dielectric layer. Finally, an upper conductor is deposited on the upper surface of the dielectric layer and the upper surface of the plug. A connection thus formed is also disclosed.