U.S. Philips Corporation

Jean-Louis Gentner

Gerard M Martin

Jean-Noel Patillon

Catherine Mallet-Mouko

Marko Erman

Christophe Guedon

A PIN photodiode having a low leakage current comprises a substrate (10) of indium phosphide (InP) which is n.sup.30 doped and on whose first surface is formed a layer (11) of indium phosphide (InP) which is n.sup.- doped and on which is disposed a MESA structure formed by a layer (b 12) of gallium indium arsenide (InGaAs) which is n.sup.- doped and is moreover constituted by a layer (13, 113, 213) of the p.sup.+ type formed at the surface, at the edges and along the circumference of the MESA structure. The structure further comprises a metallic contact (22) formed on the second surface of the substrate and an ohmic contact (21) formed on a part of the p.sup.+ layer. The invention is characterized in that the n.sup.- doping of the layer of indium phosphide (InP) (11) is chosen to be lower than the n.sup.- doping of the layer of gallium indium arsenide (InGaAs) (12), and in that the ohmic contact (21) is formed on a part (213) of the p.sup.+ zone located in the layer of indium phosphide (InP) (11) along the circumference of the MESA structure.

PIN photodiode having a low leakage current

A method of manufacturing a semiconductor device comprising at least the step of forming by a so-called method of deposition from the chloride vapour phase two superimposed epitaxial layers, the lower layer being made of a ternary compound and the upper layer being made of a binary compound, both of a semiconductor material of the III-V group, characterized in that the operating conditions of deposition temperature and molar fractions of the compounds required to form the layers are chosen so that both the lower layer of ternary material and the upper layer of binary material have before, during and after the transient state corresponding to the passage from the lower layer to the upper layer a maximum rate of coverage with chlorine (Cl) atoms. Application: hetero-structure GaInAs/InP for optoelectronic integrated circuits.

Method of forming epitaxial layers

A PIN photodiode having a low leakage current comprises a substrate (10) of indium phosphide (InP) which is n.sup.+ doped and on whose first surface is formed a layer (11) of indium phosphide (InP) which is n.sup.- doped and on which is disposed a MESA structure formed by a layer (12) of gallium indium arsenide (InGaAs) which is n.sup.- doped and is moreover constituted by a layer (13, 113, 213) of the p.sup.+ type formed at the surface, at the edges and along the circumference of the MESA structure. The structure further comprises a metallic contact (22) formed on the second surface of the substrate and an ohmic contact (21) formed on a part of the p.sup.+ layer. The invention is characterized in that the n.sup.- doping of the layer of indium phosphide (InP) (11) is chosen to be lower than the n.sup.- doping of the layer of gallium indium arsenide (InGaAs) (12), and in that the ohmic contact (21) is formed on a part (213) of the p.sup.+ zone located in the layer of indium phosphide (InP) (11) along the circumference of the MESA structure.

Pin photodiode having a low leakage current

An integrated semiconductor arrangement of the coupling type between a photodetector D and a light wave guide G.sub.1, operating in a band of given wavelengths, containing on the surface of a semiconductor substrate S of a III-V compound one after the other a confining layer C.sub.0 of III-V compound and a transparent layer C.sub.1 of a III-V compound for the operating wavelengths having an index superior to that of the confining layer, the light waveguide G.sub.1 being realized in layer C.sub.1, and also containing an absorbing layer C.sub.3 of a III-V compound for the operating wavelengths having an index superior to that of the waveguide, in which layer C.sub.3 the photodetector is realized, characterized in that the absorbing layer C.sub.3 is deposited on top of the transparent layer C.sub.1 such that the photodetector is formed on the surface of the light wave guide G.sub.1 and coupled to the latter in parallel with its axis over a given coupling length L.sub.2 of which is a function the amount of light issued by the guide and received by the photodetector. This arrangement can also include, deposited between the transparent layer C.sub.1, hereinafter called first transparent layer and the absorbing layer C.sub.3, a second transparent layer C.sub.2 of a III-V compound for the operating wavelengths having an index lying between that of the first transparent layer C.sub.1 and that of the absorbing layer C.sub.3.

Growing community of inventors

Saint-Maur, France

Jean-Louis Gentner