Gas phase epitaxy method

Abstract

The invention provides a gas phase epitaxy method having the following method steps: growing a III-V layer having a doping changing from a first conductivity type to a second conductivity type on a surface of a substrate or on a front layer in a reaction chamber from a gas phase of an epitaxial gas stream, the epitaxial gas stream has a carrier gas, at least one first precursor for an element in the III. Main group, and at least one second precursor for an element in the V. main group, where the first growth height is reached and the second growth height is reached; setting a first doping initial value of the first conductivity type by means of a ratio of a first mass flow of the first precursor to a second mass flow of the second precursor in the epitaxial gas flow; subsequently, the first doping initial value is reduced to a second doping initial value of the first or low second conductivity type; varying the first doping initial value step by step or continuously across a transition region layer having a growth height of at least 10 [mu] m until a doping target value of the second conductivity type is reached.

Description

technical field [0001] The invention relates to a vapor phase epitaxy method. Background technique [0002] Various vapor phase epitaxy installations are known for the epitaxial production of semiconductor layers, for example the vapor phase epitaxy installation of the company Aixtron. [0003] What these installations have in common is that the epitaxial layer is deposited or grown from the vapor phase on the substrate introduced into the reaction chamber. For this, the reaction chamber is heated and an epitaxial gas flow is introduced into the reaction chamber. [0004] The composition of the gas flow depends on the type of layer to be grown, wherein typical precursors such as arsine and / or trimethylgallium provide the elements for the semiconductor layer to be grown and the doping of the layer is also added if necessary Precursors for dopants. The precursors are introduced into the reaction chamber by means of a carrier gas. To control the composition of the gas strea...

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Problems solved by technology

[0005] Note also, however, that due to the reaction history there may also be additional undesired elements in the reaction chamber from previous processes

This can be problematic for producing low doped layers precisely

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