Wafer test apparatus including optical elements and method of using the test apparatus

A method of testing an electronic device on a wafer comprising:

• driving a light source with an electrical output from the electronic device on the wafer;
• supplying an optical output of the light source to a photo detector;
• and
• examining an electrical signal output from the photo detector.

A method of testing an electronic device on a wafer, comprising:

• generating an optical test signal;
• providing the optical test signal to a first photo detector;
• supplying an electrical output of the first photo detector to the electronic device on the wafer;
• driving a light source with an electrical output from the electronic device on the wafer;
• supplying an optical output of the light source to a second photo detector;
• and
• examining an electrical signal output from the second photo detector.

Apparatus adapted to test an electronic device on a wafer, comprising:

• a light source adapted to generate an optical test signal in accordance with a test control signal;
• a photo detector coupled to the light source and adapted to receive the optical test signal and convert the optical test signal into an electrical test signal;
• and
• probes connected to the photo detector and adapted to selectively couple the electrical test signal to the electronic device on the wafer.

Apparatus adapted to test an electronic device on a wafer comprising:

• a probe adapted to receive an electrical driving signal output from the electronic device on the wafer;
• a light source coupled to the probe and adapted to receive the electrical driving signal and to be driven to output an optical signal;
• a photo detector coupled to the light source and adapted to receive the optical signal and convert the optical signal to an electrical detection signal;
• and
• a monitoring circuit coupled to the photo detector and adapted to receive and monitor the electrical detection signal.

Apparatus adapted to test an electrical device on a wafer, comprising:

• a first light source adapted to generate an optical test signal in accordance with a test control signal;
• a first variable optical attenuator coupled to the first light source and adapted to receive and attenuate the optical test signal to produce an attenuated optical test signal;
• a first photo detector coupled to the first variable optical attenuator and adapted to receive the attenuated optical test signal and convert the attenuated optical test signal into an electrical test signal;
• first probes connected to the first photo detector and adapted to selectively couple the electrical test signal to the electronic device on the wafer;
• a second light source;
• a second probe adapted to receive an electrical output from the electronic device on the wafer and selectively couple the electrical output from the electronic device on the wafer to drive the second light source to output an optical output signal;
• a second variable optical attenuator coupled to the second light source and adapted to receive and attenuate the optical output signal to produce an attenuated optical output signal;
• a second photo detector coupled to the second optical attenuator and adapted to receive the attenuated optical output signal and convert the attenuated optical output signal into an electrical detection signal;
• and
• a first monitoring circuit coupled to the second photo detector and adapted to receive and monitor the electrical detection signal.

Apparatus for testing an electrical device on a wafer, comprising:

• a first light source for generating an optical test signal in accordance with a test control signal;
• a first variable optical attenuator coupled to the first light source for receiving and attenuating the optical test signal to produce an attenuated optical test signal;
• a first photo detector coupled to the first variable optical attenuator for receiving the attenuated optical test signal and converting the attenuated optical test signal into an electrical test signal;
• first probes connected to the first photo detector for selectively coupling the electrical test signal to the electronic device on the wafer;
• a second light source;
• a second probe for receiving an electrical output from the electronic device on the wafer and selectively coupling the electrical output from the electronic device on the wafer to drive the second light source to output an optical output signal;
• a second variable optical attenuator coupled to the second light source for receiving and attenuating the optical output signal to produce an attenuated optical output signal;
• a second photo detector coupled to the second optical attenuator for receiving the attenuated optical output signal and converting the attenuated optical output signal into an electrical detection signal;
• and
• a first monitoring circuit coupled to the second photo detector for receiving and monitoring the electrical detection signal.