Abstract:
A method for the manufacture of a pn junction having a high breakdown voltage at the boundary surface of a semiconductor body, utilizing a mask which has a relatively large opening for introducing a dopant therethrough into the semiconductor body, the mask having a marginal edge which extends laterally beyond the edge of the relatively large opening. In the marginal edge, the mask is provided with smaller, auxiliary openings, the openings being sized and spaced such that lesser amounts of dopant pass through the opening as the distance of the auxiliary openings from the edge of the relatively larger opening increases. Upon introducing the dopant into the semiconductor body through the mask, there is generated a doping profile which gradually approaches the boundary surface with increasing distance from the edge of the relatively large opening.
Abstract:
A semiconductor region that is inserted into a semiconductor member is provided, the latter being separated from the former by a planar pn junction including a first, more highly doped sub-region and a second, more lightly doped sub-region that is limited by a part of the pn junction that gradually approaches a boundary surface of the semiconductor member. An electrode contacts the semiconductor region and covers a part of the second sub-region and extends toward the lateral limitation of the semiconductor region to such an extent that, given the application of a voltage inhibiting the pn junction the space charge zone forming thereat has its edge lying in the boundary surface just reaching the electrode edge given a reduced breakdown voltage.
Abstract:
A method for producing a microelectronic structure is suggested in which a layer structure (30) which partially covers a substrate (5) and which comprises at least one first conductive layer (15,20) which reaches to a side wall (35) of the layer structure (30), is covered with a second conductive layer (45). The second conductive layer (45) is then subsequently back-etched to as great an extent as possible with an etching process with physical delamination, wherein delaminated material deposits on the side wall (35) of the layer structure (30). On the side wall (35) the delaminated material forms a protection layer (60) by means of which the first conductive layer (15,20) is to be protected from attack by oxygen to the furthest extent possible.
Abstract:
A bipolar transistor comprising a collector region of a first conduction type, and a subcollector region of the first conduction type at a first side of the collector region. The transistor further includes a base region of the second conduction type provided at a second side of the collector region, and an emitter region of the first conduction type which is provided above the base region on the side remote from the collection region. A carbon-doped semiconductor region is provided on the first side alongside the collector region. The bipolar transistor is characterized in that the carbon-doped semiconductor region has a carbon concentration of 1019-1021 cm−3 and the base region has a smaller cross section than the collector region and the collector region has, in the overlap region with the base region, a region having an increased doping compared with the remaining region. The carbon-doped semiconductor region prevents an outdiffusion from the zone of the collector region into the remaining region of the collector region.
Abstract:
The invention provides a memory device for storing electrical charge, which has, as memory elements, tube elements applied on an electrode layer and connect-connected thereto. The tube elements are provided with a dielectric coating, a filling material for filling the space between the tube elements being provided. A counter-electrode connected to the filling material is formed such that an electrical capacitor for storing electrical charge is formed between the electrode layer and the counter-electrode. The tube elements advantageously comprise carbon nanotubes, as a result of which the capacitance of the capacitor on account of a drastic increase in the area of the capacitor electrode surface.
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:
In producing a silicon capacitor, hole structures (2) are created in a silicon substrate (1), at the surface of which structures a conductive zone (3) is created by doping and whose surface is provided with a dielectric layer (4) and a conductive layer (5), without filling the hole structures (2). To compensate mechanical strains upon the silicon substrate (1) which are effected by the doping of the conductive zone (3), a conformal auxiliary layer (6) is formed on the surface of the conductive layer (5), which auxiliary layer is under a compressive mechanical stress.
Abstract:
Significant amounts of pattern distortion were found to be the result of reflowing borophosphosilicate glass (BPSG) and silicon dioxide shrinkage during high temperature junction anneals. In order to remedy this problem, a method for suppressing the pattern distortion by subjecting the wafer coated with BPSG and with silicon dioxide layers to a high temperature anneal before patterning is disclosed. The high temperature anneal densifies the undoped silicon dioxide before patterning, so that shrinkage of the undoped silicon dioxide does not affect the patterning steps.
Abstract:
A method for making an electrical connection between a trench storage capacitor and an access transistor in a DRAM cell. The electrical connection is formed through the selectively controlled outdiffusion of either N-type or P-type dopants present in the trench through a single crystalline semiconducting material which is grown by epitaxy (epi) from the trench sidewall. This epitaxially grown single crystalline layer acts as a barrier to excessive dopant outdiffusion which can occur in the processing of conventional DRAMs.
Abstract:
Rod-shaped or cylindrical structures in the nm range on a substrate of silicon are manufactured. A first cylinder of silicon is selectively epitaxially deposited in the hole of a mask layer of oxide, and the mask layer is removed. The silicon is then oxidized to form an oxide layer having such a thickness that a thinner, second cylinder of silicon having practically the same height as the first cylinder remains. In a last step, this oxide layer is removed, so that the second cylinder forms a freestanding silicon rod on the surface of the substrate.