Case Studies

Thermal Conductivity Solutions Using SSTR-F

Laser Thermal offers high resolution thermal measurements using steady-state thermoreflectance technology (SSTR-F). See how advanced thermal metrology is enabling better quality control and solving common conductivity challenges with thin film, sub-surface buried substrates, and more.

Using SSTR to Spatially Isolate Defect Layers on Thin Films

SSTR can measure the thermal conductivity of thin films to isolate the conductivity effects of defect layers from high quality crystalline regimes.

Using SSTR to Spatially Isolate Defect Layers on Thin Films

Measuring Thermal Conductivity and Resistance for Dielectric Films as Thin as 1 Nanometer

SSTR can measure the thermal conductivity of films as thin as 1 nm, shown here for thin dielectric films (TiO2, Al2O3 and HfO2) on silicon substrates.

Measuring Thermal Conductivity and Resistance for Dielectric Films as Thin as 1 Nanometer

Measuring the Thermal Conductivity of Buried Sub-Surface Materials and Substrates

SSTR offers the penetration ability needed to measure thermal conductivities for structures buried too deep for traditional methods.

Measuring the Thermal Conductivity of Buried Sub-Surface Materials and Substrates

Measuring In-Plane Thermal Conductivity and Anisotropy of Thin AIN Films

We used SSTR to measure the in plane thermal conductivity of thin AlN films, successfully demonstrating that their in plane thermal conductivities are record setting, exceeding the heat dissipating ability of even diamond.

Measuring In-Plane Thermal Conductivity and Anisotropy of Thin AIN Films

Measuring Extreme Thermal Conductivity Ranges

SSTR enables the measurement of extreme thermal conductivity ranges that prove challenging for traditional metrology approaches, including materials ranging from diamon to PCBM.

Measuring Extreme Thermal Conductivity Ranges

Detecting Sub-Surface Defect Layers

SSTR can be used to detect defective substrate layers at depths impossible to resolve for traditional thermal metrology techniques.

Detecting Sub-Surface Defect Layers

Nanoscale to bulk

Thermal conductivity of nanoscale thin films

SSTR is ideal for your thin film thermal conductivity testing needs.
In addition to measurements of bulk wafers and substrates (source 1, source 2), SSTR has the unprecedented spatial resolution to measure the thermal conductivity of thin films.
For example, SSTR can measure the thermal conductivity of single nanometer thick ALD grown thin films or micron thick AlN films (source).

SSTR measurements on ALD grown ultrathin film amorphous gate dielectrics (compared to TDTR) (source).

SSTR measurements of AlN crystalline thin films.2 SSTR data (temperature rise vs. power) on right for AlN film and silicon wafer control.

Validated results

SSTR-F measures the thermal conductivity of Corning Pyroceram 9606 and Corning high purity fused silica (HPFS) 7980 to within 5% of their published values.
Additional validation was provided by measuring samples from the same piece of material using the Transient Plane Source technique.
Pyroceram is no longer available from NIST but was measured on similar material to the material that was validated as a Certified Reference Material.
Corning HPFS was procured from a distributor of HPFS 7980 wafers.

	Literature Value	TPS Measurement	SSTR-F Measurement
Pyroceram 9606	4.07 +/- .26	3.95	3.95 +/- 0.2
HPFS 7980	1.38	1.39	1.39 +/- 0.09

Unparalleled reliability

Thermal conductivity measurements: Accuracy +/- 10%, Repeatability +/- 0.5%, Reproducibility +/- 1%
Accurate thermal conductivity measurements of materials in agreement with literature values
With exceptional instrumentation reliability and repeatability, SSTR-F offers unprecedented measurement stability on a daily basis for any user, exemplified by the SSTR-F data shown below. Spread in randomly sampled spots are sample related, not measurement driven.

Source

20 SSTR-F measurements at same spot

20 SSTR-F measurements at random spots

Turnkey testing

Our patented fiber-optic design enables turnkey, automated testing of thermal conductivity.
High-throughput SSTR-F testing of multiple samples facilitates, for example, screening the thermal conductivity of different thin films processed under different conditions
Defects, stresses, compositional differences, and changes in density and microstructure that occur up during film growth result in changes in thermal conductivity, easily and rapidly identified vis SSTR-F

SSTR-F data on 4 different 200 nm dielectric films on silicon with thermal conductivity ranging from ~0.35 W/m/K up to 1.8 W/m/K. SSTR-F allows for easy, rapid and automated identification of different temperature rises based on the thermal conductivity of the different films.