Abstract:
The phase change memory cell is formed by a resistive element and by a memory region of a phase change material. The resistive element has a first thin portion having a first sublithographic dimension in a first direction; and the memory region has a second thin portion having a second sublithographic dimension in a second direction which is transverse to said first direction. The first and second thin portions are in direct electrical contact and define a contact area having sublithographic extent. The second thin portion is formed in a slit of sublithographic dimensions. According to a first solution, oxide spacer portions are formed in a lithographic opening, delimited by a mold layer. According to a different solution, a sacrificial region is formed on top of a mold layer and is used for forming the sublithographic slit in the mold layer.
Abstract:
An electronic semiconductor device has a sublithographic contact area between a first conductive region and a second conductive region. The first conductive region is cup-shaped and has vertical walls which extend, in top plan view, along a closed line of elongated shape. One of the walls of the first conductive region forms a first thin portion and has a first dimension in a first direction. The second conductive region has a second thin portion having a second sublithographic dimension in a second direction transverse to the first dimension. The first and the second conductive regions are in direct electrical contact at their thin portions and form the sublithographic contact area. The elongated shape is chosen between rectangular and oval elongated in the first direction. Thereby, the dimensions of the contact area remain approximately constant even in presence of a small misalignment between the masks defining the conductive regions.
Abstract:
The phase change memory cell is formed by a resistive element and by a memory region of a phase change material. The resistive element has a first thin portion having a first sublithographic dimension in a first direction; and the memory region has a second thin portion having a second sublithographic dimension in a second direction transverse to the first dimension. The first thin portion and the second thin portion are in direct electrical contact and define a contact area of sublithographic extension. The second thin portion is delimited laterally by oxide spacer portions surrounded by a mold layer which defines a lithographic opening. The spacer portions are formed after forming the lithographic opening, by a spacer formation technique.
Abstract:
A contact structure, including a first conducting region having a first thin portion with a first sublithographic dimension in a first direction; a second conducting region having a second thin portion with a second sublithographic dimension in a second direction transverse to said first direction; the first and second thin portions being in direct electrical contact and defining a contact area having a sublithographic extension. The thin portions are obtained using deposition instead of lithography: the first thin portion is deposed on a wall of an opening in a first dielectric layer; the second thin portion is obtained by deposing a sacrificial region on vertical wall of a first delimitation layer, deposing a second delimitation layer on the free side of the sacrificial region, removing the sacrificial region to form a sublithographic opening that is used to etch a mold opening in a mold layer and filling the mold opening.
Abstract:
A cell array is formed by a plurality of cells each including a selection bipolar transistor and a storage component. The cell array is formed in a body including a common collector region of P type; a plurality of base regions of N type, overlying the common collector region; a plurality of emitter regions of P type formed in the base regions; and a plurality of base contact regions of N type and a higher doping level than the base regions, formed in the base regions, wherein each base region is shared by at least two adjacent bipolar transistors.
Abstract:
A process wherein an insulating region is formed in a body at least around an array portion of a semiconductor body; a gate electrode of semiconductor material is formed on top of a circuitry portion of the semiconductor body; a first silicide protection mask is formed on top of the array portion; the gate electrode and the active areas of the circuitry portion are silicided and the first silicide protection mask is removed. The first silicide protection mask (is of polysilicon and is formed simultaneously with the gate electrode. A second silicide protection mask of dielectric material covering the first silicide protection mask is formed before silicidation of the gate electrode. The second silicide protection mask is formed simultaneously with spacers formed laterally to the gate electrode.
Abstract:
A contact structure for a PCM device is formed by an elongated formation having a longitudinal extension parallel to the upper surface of the body and an end face extending in a vertical plane. The end face is in contact with a bottom portion of an active region of chalcogenic material so that the dimensions of the contact area defined by the end face are determined by the thickness of the elongated formation and by the width thereof.
Abstract:
A process for manufacturing an array of cells, including: implanting, in a body of semiconductor material of a first conductivity type, a common conduction region of the first conductivity type; forming, in the body, above the common conduction region, a plurality of active area regions of a second conductivity type and a first doping level; forming, on top of the body, an insulating layer having first and second openings; implanting first portions of the active area regions through the first openings with a doping agent of the first conductivity type, thereby forming, in the active area regions, second conduction regions of the first conductivity type; implanting second portions of the active area regions through the second openings with a doping agent of the second conductivity type, thereby forming control contact regions of the second conductivity type and a second doping level, higher than the first doping level; forming, on top of the body, a plurality of storage components, each storage component having a terminal connected to a respective second conduction region.
Abstract:
The phase-change nonvolatile memory array is formed by a plurality of memory cells extending in a first and in a second direction orthogonal to each other. A plurality of column-selection lines extend parallel to the first direction. A plurality of word-selection lines extend parallel to the second direction. Each memory cell includes a PCM storage element and a selection transistor. A first terminal of the selection transistor is connected to a first terminal of the PCM storage element, and the control terminal of the selection transistor is connected to a respective word-selection line. A second terminal of the PCM storage element is connected to a respective column-selection line, and a second terminal of the selection transistor is connected to a reference-potential region while reading and programming the memory cells.