Abb Research Ltd.

Okmetic Ltd.

Erik Janzen

Andrei Konstantinov

Christopher Ian Harris

Olle Kordina

Marko Tuominen

Rositza Todorova Yakimova

Asko Erkki Vehanen

Alex Ellison

Chun-Yuan Gu

A method for introducing an impurity dopant into a semiconductor layer of SiC is provided. Ions are implanted into the semiconductor layer so that a near surface of the semiconductor layer becomes doped and amorphous. The semiconductor layer is then annealed at a temperature so that the dopant diffuses into a non-implanted sublayer of the semiconductor layer below the near surface layer.

Method for introduction of an impurity dopant in SiC, a semiconductor

In a method for epitaxially growing objects of SiC, a Group III-nitride or alloys thereof on a substrate (13) received in a susceptor (7) having circumferential walls (8) these walls and by that the substrate and a source material (24) for the growth are heated above a temperature level from which sublimation of the material grown starts to increase considerably. The carrier gas flow is fed into the susceptor towards the substrate for carrying said source material to the substrate for said growth. At least a part of said source material for said growth is added to the carrier gas flow upstream the susceptor (7) and carried by the carrier gas flow to the susceptor in one of a) a solid state and b) a liquid state for being brought to a vapor state in a container comprising said susceptor by said heating and carried in a vapor state to said substrate for said growth.

Device for epitaxially growing objects

A device for epitaxially growing objects of for instance SiC by Chemical Vapor Deposition on a substrate has a first conduit (24) arranged to conduct substantially only a carrier gas to a room (18) receiving the substrate and a second conduit (25) received in the first conduit, having a smaller cross-section than the first conduit and extending in the longitudinal direction of the first conduit with a circumferential space separating it from inner walls of the first conduit. The second conduit is adapted to conduct substantially the entire flow of reactive gases and it ends as seen in the direction of the flows, and emerges into the first conduit at a distance from said room.

Device for epitaxially growing objects and method for such a growth

A method for epitaxially growing objects of SiC, a Group III-nitride or alloys thereof by Chemical Vapor Deposition on a substrate received in a susceptor having circumferential walls, the method comprises heating the circumferential susceptor walls, and thereby the substrate and a gas mixture led to the substrate for the growth, above a temperature level at which sublimination of the material grown starts to considerably increase, and feeding the gas mixture into the susceptor with a composition and at a rate that ensures a positive growth.

Device and a method for epitaxially growing objects by CVD

A semiconductor device comprises a semiconductor layer of SiC and an insulating layer thereon for insulating the SiC layer with respect to a metal plate constituting a gate and connectable to a voltage for creating a conducting surface channel at a SiC layer-insulating layer interface, wherein at least a portion of the insulating layer closest to the interface is made of a crystalline material which is substantially lattice-matched to SiC and has substantially the same coefficient of thermal expansion as SiC; and wherein the material has AlN as the only component or as a major component of an alloy with insulating properties.

Semiconductor device having an insulated gate

A method for introduction of an impurity dopant into a semiconductor layer of SiC comprises the step of ion implantation of the dopant in the semiconductor layer at a low temperature. The ion implantation is carried out in such a way that a doped and amorphous near-surface layer is formed, and the implantation step is followed by a step of annealing the semiconductor layer at such a high temperature that the dopant diffuses into the non-implanted sub-layer of the semiconductor layer following the near-surface layer.

A transistor of SiC having an insulated gate comprises a drain contact with a highly doped substrate layer formed on the drain. The substrate layer is of p-type or of n-type. For a p-type transistor, a highly doped n-type buffer layer may optionally be formed on top of the substrate layer. A low doped n-type drift layer, a highly doped p-type base layer, a highly doped n-type source region, and a source contact are then superimposed on the substrate layer. A vertical trench extends through the source region and the base layer to at least the drift layer. The trench has a wall next to these layers. A gate electrode extends vertically along the wall and at least over a vertical extension of the base layer. An insulating layer is arranged between the gate electrode and at least the base layer whereby an inversion channel is formed for electron transport from the source contact to the drain contact. An additional low doped p-type layer is arranged in the channel region laterally to the base layer, between the base layer and the insulating layer. The additional layer extends vertically over at least the base layer.

IGBT having a vertical channel

A method for producing a semiconductor device, having a semiconductor layer of a SiC comprises the steps of a) supplying dopants to the surface of the SiC layer during heating thereof for diffusion of the dopants into the SiC layer, and b) highly doping at least a portion of the surface layer of the SiC layer prior to step a) to control diffusion of the dopants into the SiC layer under the surface layer portion.

Method for producing a semiconductor device having a semiconductor layer

A method for protecting a susceptor when SiC, a Group III-nitride or alloys thereof, is epitaxially grown by chemical vapor deposition on a substrate arranged on a surface of the susceptor includes the steps of heating the susceptor and thus the substrate and a gas mixture fed to the substrate for the growth, placing a plate made of SiC, an alloy of SiC and the material grown, or the material grown, on the susceptor and arranging the substrate on the plate.

Method for protecting the susceptor during epitaxial growth by CVD and a

A device for epitaxially growing objects of SiC by Chemical Vapor Deposition on a substrate comprises a substantially cylindrical susceptor having continuous circumferential walls with a substantially uniform thickness surrounding a chamber receiving the substrate, the walls being surrounded by thermal insulation. The circumferential susceptor walls and thereby the substrate and a gas mixture fed to the substrate for the growth are heated to a temperature level in the range of 2000.degree.-2500.degree. C. at which sublimation of the grown material starts to considerably increase. The gas mixture is fed into the susceptor with a composition and at a rate that ensures a positive growth.

The present invention relates to a method for producing a semiconductor device having a semiconductor layer of SiC. The method comprises the steps of a) applying a mask on at least a portion of the SiC layer to coat a first portion of the SiC layer leaving a second portion thereof uncoated, b) applying a heat treatment to the SiC layer, and c) supplying dopants to the SiC layer during the heat treatment for diffusion of the dopants into the SiC layer at the second portion thereof for doping the SiC layer. The mask is made of crystalline AIN as the only component or AIN as a major component of a crystalline alloy constituting the material.

A semiconductor device comprises at least one semiconductor layer (1-3) of SiC and a layer (6) applied on at least a portion of an edge surface (19) of said SiC-layer so as to passivate this edge surface portion. At least the portion of said passivation layer closest to said edge surface portion of the SiC-layer is made of a first crystalline material, and the passivation layer comprises a portion made of a second material having AIN as only component or as a major component of a crystalline alloy constituting said second material.

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Borensberg, Sweden

Erik Janzen