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US 4,906,583 AGranted
Making a semiconductor photodetector
AssigneeFujitsu Limited
InventorsShuzo Kagawa, Junji Komeno
Life of this patent
Estimating the term…
Abstract
A semiconductor photodetector, such as a PIN photodiode and an avalanche photodiode, comprising an InP substrate, a first InP layer, a GaInAs or GaInAsP light absorbing layer, and a second InP layer. All of the layers are successively grown by a vapor phase epitaxial process wherein the lattice constant of the GaInAs (GaInAsP) layer is larger than that of the InP layer at room temperature. The photodetector has a low dark current.
Claims9
A method of forming a semiconductor photodiode comprising the steps of:
- preparing a InP substrate;
- growing a InP buffer layer on said InP substrate by a vapor phase epitaxial process using a gas including P and In;
- growing a Ga.sub.1-x In.sub.x As light absorbing layer on said InP buffer layer by a vapor phase epitaxial process while controlling the flow rates of As gas, Ga gas and In gas such that the lattice mismatching degree (.DELTA.a/a) between said Ga.sub.1-x In.sub.x As light absorbing layer and said InP buffer layer is more than 0% and less than 0.2% at room temperature, as defined by the equation:
- ##EQU2## gorwing a cap layer on said Ga.sub.1-x In.sub.x As layer;
- and introducing impurity ions into said cap layer so as to make a Pn junctions.
2 more elements
A method of forming a semiconductor photodiode comprising the steps of;
- preparing a InP substrate;
- growing a InP buffer layer on said InP substrate by a vapor phase epitaxial process using a gas including P and In;
- growing a Ga.sub.1-x In.sub.x As.sub.1-y P.sub.y light a absorbing layer on said InP buffer layer by a vapor phase epitaxial process while controlling the flow rates of As gas, Ga gas, In gas, and P gas such that the lattice mismatching degree (.DELTA.a/a) between said Ga.sub.1-x ln.sub.x As.sub.1-y P.sub.y light absorbing layer and said InP buffer layer is more than 0% and less than 0.2% at room temperature, as defined by the equation:
- ##EQU3## growing a cap layer on said Ga.sub.1-x ln.sub.x As.sub.1-y P.sub.y light absorbing layer;
- and
- introducing impurity ions into said cap layer so as to form a PN junction.
3 more elements
Dependencies are inferred from the claim text.