General

Reliability testing on probe stations focus is on long term operational related failures as opposed to sudden, event driven failures. Tests are designed to identify:

Metal Line and Via Failures:
Electromigration, Stress Voiding, Copper Interconnect (Via) Reliability
Interlayer Dielectric and Gate Oxide Failures:
Wear-out (soft and hard breakdown), Hot Carrier Injection (HCI), Negative Bias Temperature Instability (NBTI and PBTI)

Reliability Test	Tests characteristics and Equipment
Electromigration	Tests are long term with or without temperature acceleration
	Current levels can be high, ampere levels
	Defects can occur and then “heal” in rapid succession so the need is to monitor sites individually with multiple probes or probe cards
	Not light sensitive
	Multiple sites may be tested
Metal Stress Voiding Once the stress void appears, the long-term failure mechanism is Electromigration
	Test characteristics and equipment for Electromigration apply
Copper Interconnect (Via) Reliability	Copper – Low K dielectric interconnects are sensitive to light
Oxide Wear-out Time Dependent Dielectric Breakdown (TDDB) Constant Voltage Stress (CVS) Constant Current Stress (CCS)	Tests are long term with temperature acceleration and single stress interval
	Monitor current and noise levels of oxide. Pre and post stress testing measures gate leakage (low current capability is needed especially to identify soft breakdowns)
	Multiple sites may be done in parallel
	Darkness required
Hot Carrier Injection (HCI)	Tests are continuous cycling of transistor (can run 10-100 hours with constant switching)
	IDSAT and ISUB are monitored so low noise and low leakage chuck is needed
	Low temperature increases carrier mobility and accelerates failures
Negative Bias Temperature Instability (NBTI) for pMOS Transistors (PTBI) for nMOS Transistors	Test time can range from hours to weeks
	Temperatures above 100 degrees C required
	Vth and IDsat must be monitored continuously

Requirement Summary

Test	Current	Temperature	Measure through	Light Shield
EM (Al)	High	High	Probes	No
Metal Stress	High	High	Probes	No
Copper	High	High	Probes	Yes
Oxide Wear-out	Low	High	Probes	Yes
HCI	Low	Low	Substrate	No
NBTI	Low & High	High	Probes	No

All tests may make use of :

Thermal chucks are needed for accelerating failures. The H1000’s unique design is ideal.
All tests require good contact with long term stability.
Integrated systems of manipulators, probe holder and probes for high stability and contact integrity.
Individual probes are needed for small devices.
Wave manipulators with VersaTiles™ for easy configuration of multi-site contacts
Multi-site probe cards
Highly stabile, high-performance probe stations
Stations which support Wave manipulators with VersaTiles™ and Multi-site probe cards.