Method for producing an opto-electronic integrated circuit

A method for producing an opto-electric integrated circuit having a field effect transistor as an electronic device and a photo-diode as an optical device both formed on an InP substrate, comprising:

• a first step of forming a first epitaxial layer of GaInAs, a second epitaxial layer of n-AlInAs, a third epitaxial layer of n-InP, a fourth epitaxial layer of undoped GaInAs and a fifth epitaxial layer of p-GaInAs formed on an InP substrate in the stated order;
• a second step of partially removing the fifth and the fourth epitaxial layers, leaving a p-electrode region in a photo-diode region so as to expose the third epitaxial layer;
• a third step of forming an anode of said photo-diode on the fifth epitaxial layer and a cathode thereof on the third epitaxial layer in the photo-diode region, and forming a source electrode and a drain electrode of the field effect transistor on the the third epitaxial layer in a field effect transistor region;
• a fourth step of removing the third, the second and the first epitaxial layers between the photo-diode and the field effect transistor, so as to electrically separate both regions;
• a fifth step of etching the third epitaxial layer between the source electrode and the drain electrode in the field effect transistor region to expose the second epitaxial layer so as to form a gate electrode on the exposed second epitaxial layer;
• and
• a sixth step of forming a wiring for electrically connecting the thus formed photo-diode and field effect transistor.