Abstract:
For producing a laterally limited, single-crystal region on a substrate, for example the collector of a bipolar transistor or the active region of a MOS transistor, a mask layer having an opening is produced on the surface of a substrate. The surface of the substrate is exposed within the opening. The cross-section of the opening parallel to the surface of the substrate at the surface of the substrate projects laterally beyond that cross-section at the surface of the mask layer. The sidewall of the opening proceeds essentially perpendicularly relative to the surface of the substrate in the region of the surface of the mask layer and has a step-shaped profile in cross-section perpendicularly relative to the surface of the substrate. The single-crystal region is formed by selective epitaxy within the opening.
Abstract:
A turn-off thyristor whereby an n-base layer not contacted by a gate electrode has at least one thin semiconductor layer inserted into it that is oppositely doped. Its distance from a pn-junction between a p-base and the n-base is selected so small that the maximum field strength of the space charge zone building up at this pn-junction upon turn-off of the thyristor is limited to a non-critical value at which an avalanche breakdown with respect to the charge carriers to be cleared out does not yet occur.
Abstract:
The invention relates to a method for producing a bipolar transistor. A semiconductor substrate is provided that encompasses a collector area of a first conductivity type, which is embedded therein and is bare towards the top. A monocrystalline base area is provided and a base-connecting area of the second conductivity type is provided above the base area. An insulating area is provided above the base-connecting area and a window is formed in the insulating area and the base-connecting area so as to at least partly expose the base area. An insulating sidewall spacer is provided in the window in order to insulate the base-connecting area. An emitter layer which forms a monocrystalline emitter area above the base area and a polycrystalline emitter area above the insulating area and the sidewall spacer is differentially deposited and structured, and a tempering step is carried out.
Abstract:
A reactor configuration contains a housing connected to a silicon wafer. The silicon wafer has pores extending from a first main area of the silicon wafer into an interior of the silicon wafer, preferably as far as a second main area of the silicon wafer. A catalyst layer at least partly covers the surface of the pores.
Abstract:
A bipolar transistor includes a first layer with a collector. A second layer has a base cutout for a base. A third layer includes a lead for the base. The third layer is formed with an emitter cutout for an emitter. An undercut is formed in the second layer adjoining the base cutout. The base is at least partially located in the undercut. In order to obtain a low transition resistance between the lead and the base, an intermediate layer is provided between the first and the second layer. The intermediate layer is selectively etchable with respect to the second layer. At least in the region of the undercut between the lead and the base, a base connection zone is provided that can be adjusted independent of other production conditions. The intermediate layer is removed in a contact region with the base.
Abstract:
An optical structure includes a substrate having semiconductor material and a grating structure. The grating structure has the property of emitting at least one frequency band so that light having a frequency from that frequency band cannot propagate in the grating structure. The grating structure has a configuration of pores and a defective region. The pores are disposed outside the defective region in a periodic array, and the periodic array is disturbed in the defective region. A surface of the grating structure is provided with a conductive layer at least in the vicinity of the defective region. A method for producing the optical structure is also provided.
Abstract:
A first source-drain region, a channel region, and a second source-drain region are arranged one after another in a semiconductor substrate. At least the surface of the channel region and parts of the first source-drain region are covered by a dielectric layer. A ferroelectric layer is disposed on the surface of the dielectric layer between two polarization electrodes. A gate electrode is arranged on the surface of the dielectric layer. The thickness of the dielectric layer is dimensioned such that a remanent polarization of the ferroelectric layer, which is aligned between the two polarization electrodes, produces compensation charges in part of the channel region. The ferroelectric transistor is suitable as a memory cell for a memory cell configuration.
Abstract:
A method for fabricating a capacitor for a semiconductor memory configuration. In this case, a selectively etchable material is applied to a conductive support, which is connected to a semiconductor body via a contact hole in an insulator layer, and patterned. A first conductive layer is applied thereon and patterned. A hole is introduced into the first conductive layer, through which hole the selectively etchable material is etched out. A cavity is produced under the first conductive layer in the process. The inner surface of the cavity and the outer surface of the first conductive layer are provided with a dielectric layer, to which a second conductive layer is applied and patterned.
Abstract:
A bottle-shaped trench capacitor having an expanded lower trench portion with an epi layer therein. The epi layer serves as the buried plate of the trench capacitor. A diffusion region surrounds the expanded lower trench portion to enhance the dopant concentration of the epi layer. The diffusion region is formed by, for example, gas phase doping, plasma doping, or plasma immersion ion implantation.
Abstract:
The memory cell has transistors that are arranged three-dimensionally. Vertical MOS transistors are arranged on the sidewalls of semiconductor webs, and a plurality of transistors are arranged one above the other on each sidewall. The transistors that are arranged one above the other on a sidewall are connected in series.