What is Curve Tracing?

Curve Tracing is a specialized electronic test method that analyzes I-V characteristics of semiconductor devices. Failure analysis engineers and component test labs utilize this technique. RTI’s curve trace test systems can detect electrically damaged or counterfeit devices, and measures many DC parameters in a datasheet.

RTI’s Test Systems

RTI’s curve trace systems are modular. They allow configurations to match test applications and provide flexibility to incorporate other instruments to expand the curve trace system’s applications and uses.

RTI provides curve trace test systems with powered and unpowered test capabilities, and curve trace relevant peripherals and accessories.

Curve Trace Uses

Curve Tracing serves a variety of engineering applications for testing and verification of a wide range of devices. Popular applications are failure analysis, reliability and latch-up testing, and counterfeit IC detection. RTI provides top of the line curve trace systems to fulfill these test needs.

Failure Analysis labs use curve tracing as a non-destructive test to assess if electrical continuity of a semiconductor device meets the criteria listed on the device’s datasheet or as compared to another device. Some companies use F/A labs to support OCM, OEM and Fabless customers with additional high-end testing capabilities. The MultiTrace or MegaTrace can fulfill these additional tests:

Incoming nondestructive electrical test is used to confirm failure complaint, collect electrical evidence and verify continuity of the test signals. The MultiTrace can stimulate the device failure so that it can be analyzed.

Opens, shorts leakage testing (OSL) evaluates current leakage and alerts the user of pins disconnected or shortened to another pin. The MultiTrace can measure current leakages down to 1nA.

Post decap electrical inspection removes the plastic package to expose the die. Curve tracing before and after this test and comparing the data gives the user confidence the failure did not change as a result of the decap test.

Optical fault localization isolates the area where the electrical defect exists. The device needs to be powered for the procedure to yield useful images. The MultiTrace is a great tool for biasing the device with DC testing. MultiTrace can stimulate the same test conditions used to find and characterize the failure.

Reliability testing ensures the device is robust and can withstand electrical stresses displayed in the datasheets. Some of these tests are:

ESD testing subjects the pins of the device to electrical ESD pulses then tests for possible failures. RTI built the MultiTrace curve trace system to offer great sensitivity and more test conditions compared to the ESD testing equipment. This allows great back up to the ESD test and more range of applications and uses. ESD testing also generates a need for basic failure analysis due to failed devices. MultiTrace combines these required tools and more to present a full package for various tests.

Latch-Up testing is still required to qualify IC designs prior to delivery to a customer. The MultiTrace is fully compatible with current Latch-Up specifications and is proficient in characterization and qualification tests.

Counterfeits have been a rising problem in the modern market. Most companies that handle IC devices are affected. OCMs handle the fallout from devices customers think is the company’s product but are not. OEMs screen parts to eliminate from their stock so it doesn’t compromise the reliability of their products. IC distributors ensure parts they sell are quality supplies.

The MultiTrace is flexible for IC characterization and offers the best balance between precision and flexibility. The curve trace system features configurable multi-channel switch matrixes that allow for a wide range of test varieties and conditions. With multiple source measure units (SMU), the curve trace can provide multiple bias voltage or current to devices for powered testing. Measurements obtained are high precision and allow for screening devices to a tighter tolerance, accuracy, and repeatability. Since the MultiTrace is designed for this task, the MTForms Software is optimized for configuring to these various test conditions and analyses of the data produced.

Curve Trace Methods

RTI’s curve trace models can be used in conjunction with our software suite, which includes MTForms. MTForms design is to simplify set up and operation of the curve trace system. The software contains four general test methods: unpowered curve tracing, powered curve tracing, supply current measurement and latch-up testing.

Unpowered curve trace is a fundamental test method used on any semiconductor IC device for finding damaged pins, shortened pins, current leakage, and more. This method is flexible in selecting grounded pins, pins to test, and what parameters to use.

Powered curve trace powers up the device and traces the pins with respect to active supplies. Simultaneously, the system collects IV data and supply current and allows you to display the data on a single graph.

RTI’s MTForms Software supports 2 standard methods:

The first is the single point method which can be run on a continuous loop allowing the user to change logic levels on input pins to see changes in the supply current. This method is typically used for emission microscopy and searching for IDDQ core faults.

The second method is ramp VDD mode that investigates relative supply currents, domain to domain protection circuits, and stimulation of supply current leakage.

A software option in RTI’s MTForms is used to qualify parts as resistant to CMOS Latch Up by reliability engineers. FA engineers may use this method to characterize control samples when a failure device is suspected. Emission images can be captured to learn what structures of the device are susceptible.