Wafer testing is an
important step of semiconductor device fabrication. The wafer testing is done by
test equipment known as Wafer Prober.
Types of Wafer Testing:
1.
Wafer Final Test (WFT)
2.
Electronic Die Sort (EDS)
3.
Circuit Probe (CP)
During this process, Silicon
wafer is sent for die preparation. In this process, Integrated circuits present
on the wafer are tested for functional defects. This is done by applying the
special test pattern.
The Wafer Prober’s Role is Silicon Wafer Testing:
Wafer probe is a device
used to test integrated circuits. A probe card is used for electrical testing
of the silicon wafers. The Wafer is moved into electrical contact by means of
Vacuum-mounted on their surface. Die electrically test the Prober to start the
next test. The wafer Prober is equipped with automatic pattern recognition
optics. It is responsible for loading and unloading of the Silicon wafers. It
is also capable of aligning the wafers together. The Silicon Test Wafers probe exercises test circuitry on the wafer
scribe lines.
Non-Contact
Wafer Testing
This method is for Silicon Test Wafer. It is an
alternative to mechanical probing of integrated circuits. In this method, tiny
RF antennae are used to replace both the mechanical probes and the metal probe
pads.
Benefits
of Non-Contact Wafer Testing:
1.
No damage is done to circuits and probe
cards.
2.
No debris is produced
3.
Probe cards are not required.
4.
Wireless probe points can be placed
anywhere IC
5.
The wafer probe does not exert any force
on the Silicon Wafers.
6.
Repeated probing is possible without
damaging the probe points
7.
Faster data rates are possible than with
mechanical probes
