摘要:
A reduced pressure epitaxial deposition method is disclosed to maximize performance and leakage limited yield of devices formed in the epitaxial layer. The method includes specified prebake and deposition conditions designed to minimize arsenic (buried subcollector) and boron (buried isolation) autodoping effects when pressures below one atmosphere are selected in accordance with the subcollector-to-isolation area ratio.
摘要:
The method suggests the replacement of all or part of the solid or blanket buried region, typically a subcollector region of a bipolar transistor, by a mesh or stripe shaped subcollector. During subsequent thermal processing involving growth of the epitaxial layer, the stripes will at least partially merge, resulting in a solid subcollector. The method of minimizing autodoping implies only a special design of the subcollector mask. Therefore, there is no longer any need for technological changes either in the process or in the equipment. The method also applies to other buried layers, such as, subemitters, resistors, bottom isolation regions, etc.
摘要:
The invention relates to the manufacture of an epitaxial layer, with the following steps: providing a semiconductor substrate; providing a Si-Ge layer on the semiconductor substrate, having a first depth; - providing the semiconductor substrate with a doped layer with an n-type dopant material and having a second depth substantially greater than said first depth; performing an oxidation step to form a silicon dioxide layer such that Ge atoms and n-type atoms are pushed into the semiconductor substrate by the silicon dioxide layer at the silicon dioxide / silicon interface, wherein the n-type atoms are pushed deeper into the semiconductor substrate than the Ge atoms, resulting in a top layer with a reduced concentration of n-type atoms; removing the silicon dioxide layer; growing an epitaxial layer of silicon on the semiconductor substrate with a reduced outdiffusion or autodoping.
摘要:
A method for controlling the autodoping during epitaxial silicon deposition. First, the substrate (10) is cleaned to remove any native oxide. After being cleaned, the substrate (10) is transferred to the deposition chamber in an inert or vacuum atmosphere to inhibit the growth of a native oxide on the surface of the wafers. A lower temperature (i.e., 500-850 ºC) capping layer (14) is deposited to prevent autodoping. Then, the temperature is increased to the desired deposition temperature and the remainder of the epitaxial layer (18) is deposited.
摘要:
Sealing the backside of a semiconductor wafer prevents evaporation of the dopant (typically boron) when an epitaxial layer is grown on the front (active) side, thereby preventing autodoping of the epitaxial layer with excess dopant. The present technique deposits an oxide layer during the ramp-up of the furnace that also deposits the nitride cap, thereby avoiding an extra process step. Il also avoids the higher temperatures required for the prior-art technique of growing the oxide layer, resulting in lower oxygen precipitation due to the capping process and a greater yield of usable wafers.
摘要:
Bei dem Verfahren zum Aufwachsen von Epitaxieschichten auf selektiv hochdotierte Siliciumsubstrate, wird das Substrat zunächst in einer Wasserstoffatmosphäre im Bereich zwischen ungefähr 1120 und ungefähr 1180 °C eine festgelegte Zeit lang erhitzt, anschließend auf eine Temperatur im Bereich zwischen ungefähr 1000 und ungefähr 1100°C abgekühlt und schließlich einem Gasstrom ausgesetzt, der Wasserstoff als Trägergas und Siliciumtetrachlorid als Quellmaterial für das Silicium enthält. Dabei wächst die Epitaxieschicht auf. Mit dem Verfahren werden bevorzugt Epitaxieschichten erzeugt, weiche
摘要:
A method for forming a semiconductor device with a layered structure of thin and well defined layer of activated dopants, is disclosed. In the method, a region in a semiconductor substrate is amorphized, after which the region is implanted with a first dopant at a first doping concentration. Then a solid phase epitaxy regrowth step is performed on a thin layer of desired thickness of the amorphized region, in order to activate the first dopant only in this thin layer. Subsequently, a second dopant is implanted in the remaining amorphous region at a second doping concentration. Subsequent annealing of the substrate activates the second dopant only in said remaining region, so a very abrupt transition between dopant characteristics of the thin layer with first dopant and the region with the second dopant is obtained.
摘要:
A bifacial solar cell including a semiconductor substrate wafer, a first active area of a first conductivity type provided on at least a part of a first side of the wafer and a second active area of a second conductivity type provided on a second side of the wafter, the edge face of the wafter and the periphery of said first side of the wafter. The first active area and second active area are separated by a distance lambda , the distance lambda allowing a leakage current to flow between the first and second active areas.