A semiconductor device includes a landing pad on a substrate, a lower electrode on the landing pad and connected to the landing pad, the lower electrode including an outer portion, the outer portion including first and second regions, and an inner portion inside the outer portion, a dielectric film on the lower electrode to extend along the first region of the outer portion, and an upper electrode on the dielectric film, wherein the outer portion of the lower electrode includes a metal dopant, a concentration of the metal dopant in the first region of the outer portion being different from a concentration of the metal dopant in the second region of the outer portion.

The present application discloses a method for fabricating a semiconductor device including providing a substrate comprising an array region and a peripheral region surrounding the array region, forming a first semiconductor element positioned above the peripheral region and having a first threshold voltage and a second semiconductor element positioned above the peripheral region and having a second threshold voltage, and forming a plurality of capacitor structures positioned above the peripheral region of the substrate. The first threshold voltage of the first semiconductor element is different from the second threshold voltage of the second semiconductor element.

A semiconductor device includes: a substrate; a first dielectric layer over the substrate; a memory cell over the substrate in a first region of the semiconductor device, where the memory cell includes a first ferroelectric structure in the first dielectric layer, where the first ferroelectric structure includes a first bottom electrode, a first top electrode, and a first ferroelectric layer in between; and a tunable capacitor over the substrate in a second region of the semiconductor device, where the tunable capacitor includes a second ferroelectric structure, where the second ferroelectric structure includes a second bottom electrode, a second top electrode, and a second ferroelectric layer in between, where at least a portion of the second ferroelectric structure is in the first dielectric layer.

A memory device includes a substrate, a bit line, a first insulating film, a second insulating film, a third insulating film, and a contact. The bit line is disposed over the substrate. The first insulating film is disposed on a sidewall of the bit line. The second insulating film is disposed on the first insulating film and is made of a different material than the first insulating film. The third insulating film is disposed on the second insulating film and is made of a different material than the second insulating film. The top surfaces of the second insulating film and the third insulating film are lower than the top surface of the first insulating film. The contact is disposed over the substrate and adjacent to the bit line. The width of the lower portion of the contact is less than the width of the upper portion of the contact.

Embodiments provide a semiconductor structure. The semiconductor structure includes a substrate, a dielectric layer arranged on the substrate, and a plurality of memory cell layers. The plurality of memory cell layers are spaced in the dielectric layer along a first direction, and projections of any adjacent two of the plurality of memory cell layers on the substrate are overlapped. Each of the plurality of memory cell layers includes a plurality of memory cells spaced along a second direction. According to the embodiments, the plurality of memory cell layers are spaced in the dielectric layer along a direction perpendicular to the substrate, and each of the plurality of memory cell layers has a plurality of memory cells therein; and a source, a channel and a drain in each of the plurality of memory cells are arranged along a direction parallel to the substrate.

Embodiments provide a method for fabricating a semiconductor structure. The method includes: providing a substrate, where the substrate includes semiconductor channels arranged in an array along a first direction and a second direction, and a part of the substrate is exposed between adjacent semiconductor channels; forming a spacer positioned between adjacent semiconductor channels, where a top surface of the spacer is lower than top surfaces of the semiconductor channels; forming a bit line positioned in the substrate, where a top surface of the bit line contacts and connects bottom surfaces of the semiconductor channels; forming a protective layer, where a part of the protective layer is positioned on the top surface of the spacer between the semiconductor channels arranged along the second direction, and another part of the protective layer is positioned on the top surface of the spacer between the semiconductor channels arranged along the first direction.

A semiconductor structure and the method for forming the same are provided. The method includes: providing a substrate including an active region; forming a word line in the substrate including a first portion and a second portion located at the end of the first portion, wherein the second portion of the word line protrudes from the first portion of the word line along the direction perpendicular to the substrate; forming a dielectric layer covering the substrate; and etching the dielectric layer and a part of the substrate to simultaneously form a first contact hole exposing the second portion of the word line and a second contact hole exposing the active region. The invention reduces the etching time and improves the etching efficiency. It avoids an excessively large etching depth of the second contact hole, thereby reducing the damage to the active region and the leakage current inside the semiconductor structure.

The semiconductor structure manufacturing method includes the steps of: providing a substrate with bit line contact regions and isolation regions located between adjacent bit line contact regions; forming a groove in the substrate, the bottom of the groove exposes the bit line contact region and the isolation region adjacent to the bit line contact region; forming a contact region isolation layer covering at least sidewalls of the groove; and forming a contact region to cover the contact region isolating the surface of the layer and filling the bit line contact layer of the groove, the bit line contact layer being in contact with the bit line contact region at the bottom of the groove; forming a bit line layer on the bit line contact layer. The invention avoids damage to the sidewalls of the active region in the substrate.

There are an N.sup.+ layer connected to a source line SL and an N.sup.+ layer connected to a bit line BL at both ends of a Si pillar standing on a substrate in a perpendicular direction, a P.sup.+ layer connected to the N.sup.+ layer, a first gate insulating layer surrounding the Si pillar, a first gate conductor layer surrounding the first gate insulating layer and connected to a plate line PL, and a second gate conductor layer surrounding a gate HfO.sub.2 layer surrounding the Si pillar and connected to a word line WL. The voltages applied to the source line SL, the plate line PL, the word line WL, and the bit line BL are controlled to perform a data hold operation of holding a group of holes generated by an impact ionization phenomenon or a gate-induced drain leakage current inside a channel region of the Si pillar and a data erase operation of removing the group of holes from the channel region.

Vertical integration schemes and circuit elements architectures for area scaling of semiconductor devices are described. In an example, an inverter structure includes a semiconductor fin separated vertically into an upper region and a lower region. A first plurality of gate structures is included for controlling the upper region of the semiconductor fin. A second plurality of gate structures is included for controlling the lower region of the semiconductor fin. The second plurality of gate structures has a conductivity type opposite the conductivity type of the first plurality of gate structures.