This is a practical guide to Surface Science for researchers working in the Semiconductors Industry.
In this all-new guide you’ll learn all about:
Let’s dive right in.
In semiconductor manufacturing, many yield losses start at a surface. A wafer that still carries a thin organic film after cleaning gives poor resist adhesion. A package surface with adhesive residue gives weak bonds and delamination later.
These are the places where wetting decides yield in semiconductor work:
The Dropometer contact angle and surface energy kit measures contact angle, surface tension, surface free energy and sliding angle with one portable setup. Its method was validated against a KRUSS DSA100E in two peer reviewed papers. If you are new to the terms, start with wettability.
We use the following surface properties to understand the behavior of Semiconductors products and improve their quality.
Sample Image taken from Droplet Lab Tensiometer.
Young – Laplace Method
Polynomial Method
Ideally, when we place a drop on a solid surface, a unique angle exists between the liquid and the solid surface. We can calculate the value of this ideal contact angle (the so-called Young’s contact angle) using Young’s equation. In practice, due to surface geometry, roughness, heterogeneity, contamination, and deformation, the contact angle value on a surface is not necessarily a single consistent value but rather falls within a range. The upper and lower limits of this range are known as the advancing and receding contact angles, respectively. The values of advancing and receding contact angles for a solid surface are highly sensitive to many parameters, such as temperature, humidity, homogeneity, and minor contamination of the surface and liquid. For example, the advancing and receding contact angles of a surface can differ at different locations.
Practical surfaces and coatings naturally show contact angle hysteresis, indicating a range of equilibrium values. When we measure static contact angles, we get a single value within this range. Solely relying on static measurements poses problems, like poor repeatability and incomplete surface assessment regarding adhesion, cleanliness, roughness, and homogeneity.
In practical applications, we need to understand how easily a liquid spreads (advancing angle) and how easily it is removed (receding angle), such as in painting and cleaning. Measuring advancing and receding angles offers a holistic view of liquid-solid interaction, unlike static measurements, which yield an arbitrary value within the range.
This insight is crucial for real-world surfaces with variations, roughness, and dynamics, aiding industries like cosmetics, materials science, and biotechnology in designing effective surfaces and optimizing processes.
Learn how Contact Angle measurement is done on our Tensiometer
For a more complete understanding of Contact Angle measurement, read our Contact Angle measurement: The Definitive Guide
These reference measurements show how deionized water wets four standard substrates measured with the Droplet Lab Dropometer. Use them as visual and numerical benchmarks when you're checking your own sample preparation, treatments, and chemistry.
Full contact angle and surface energy datasets (including additional liquids and statistics) are available on our dataset hub.
The droplet images above are taken from the same benchmark series as our open dataset. For each substrate and probe liquid we report:
● Advancing and receding contact angles (and hysteresis)
● Derived surface energy (SFE) values based on multi-liquid measurements
● Measurement conditions, uncertainties, and sample preparation details
Comparing your own droplet shapes and angles against these references is a fast way to spot contamination, treatment drift, or unexpected changes in wettability.
This property measures the force that acts on the surface of a liquid, aiming to minimize its surface area.
Sample Image taken from Droplet Lab Tensiometer
Dynamic Surface Tension
Dynamic surface tension differs from static surface tension, which refers to the surface energy per unit area (or force acting per unit length along the edge of a liquid surface).
Static surface tension characterizes the equilibrium state of the liquid interface, while dynamic surface tension accounts for the kinetics of changes at the interface. These changes could involve the presence of surfactants, additives, or variations in temperature, pressure, and composition at the interface.
When to use Dynamic Surface Tension Measurement
Dynamic surface tension is essential for processes that involve rapid changes at the liquid-gas or liquid-liquid interface, such as droplet and bubble formation, coalescence (change in surface area), the behavior of foams, and the drying of paints (change in composition, e.g., evaporation of solvent). It is measured by analyzing the shape of a hanging droplet over time.
Dynamic surface tension applies to various industries, including cosmetics, coatings, pharmaceuticals, paint, food and beverage, and industrial processes, where understanding and controlling the behavior of liquid interfaces is essential for product quality and process efficiency.
Learn how Surface Tension measurement is done on our Tensiometer
For a more complete understanding of Surface Energy measurement, read our Surface Tension measurement: The Definitive Guide
Sample Image taken from Droplet Lab Tensiometer
Learn how Surface Energy measurement is done on our Tensiometer
For a more complete understanding of Surface Energy measurement, read our Surface Energy measurement: The Definitive Guide
For benchmark contact angle and surface energy values on glass, nylon, PMMA, and Teflon, see the Open Benchmark Data panel above or visit our Dataset Hub for full CSV downloads.
The sliding angle measures the angle at which a liquid film slides over a solid surface. It is commonly employed to assess the slip resistance of a surface.
Sample Image taken from Droplet Lab Tensiometer
Learn how Sliding Angle measurement is done on our Tensiometer
For a more complete understanding of Sliding Angle measurement, read our Sliding Angle Measurement: The Definitive Guide
Within the Semiconductors industry, several case studies exemplify the advantages of conducting surface property measurements.
Resist sticks well only to a surface that is clean and primed to the right wetting state. Water contact angle after the clean and the primer step gives a number you can trend for every lot, in place of a visual check.
Our wafer cleaning and photoresist adhesion page sets out the test plan. SEMI/ASTM D7490 describes working out surface free energy from contact angles of two probe liquids, often water and diiodomethane. The US R&D site of a global fused silica and quartz maker runs all three on one unit; see the fused silica and quartz case study.
Tapes and temporary bonding adhesives can leave a thin film after removal that weakens the next bond, mold or underfill step. A hydrophobic residue raises the water contact angle, so a spot map across the part shows where cleaning fell short.
ASTM F22 describes a visual water break test and ASTM F21 an atomizer test; both give a go or no go call. Contact angle adds a number at chosen spots and supplements those tests rather than replacing them. On rough surfaces, the Clemson graphene electrode case study shows why the fitting method matters, and ISO 25178 defines the texture parameters to report alongside.
In immersion lithography, water sits between the lens and the wafer while the stage moves. If the receding contact angle of the resist or topcoat is too low, water can stay behind on the wafer and leave defects.
Sliding angle on a tilting stage shows how easily water moves off a surface. The drop at the point of motion gives the advancing and receding angles. Compare topcoat candidates on the same stage and tilt rate. Our sliding angle measurement guide and the glossary entry on dynamic contact angles explain the method.
If you are interested in implementing these or any other applications, please contact us.
In an industry where precision reigns supreme, how can Semiconductors manufacturers ensure their products withstand scrutiny? The answer lies in standards and guidelines: the compass that guides them through the complex maze of quality and performance.
Standard practice for estimating a solid’s total surface free energy and separating it into dispersive and polar components by measuring sessile‑drop contact angles of two probe liquids (one polar, one non‑polar) of known surface tension on the surface. It is intended as a quantitative, comparative surface‑readiness metric for wetting/adhesion process control within an approximate applicable range of ~20-60 mN/m.
Use fixed‑time contact angles plus calculated γ components to confirm surface cleaning/treatment/priming is within a validated “pass band” before committing to downstream trials.
Trend γs,polar/γs,dispersive and spot‑to‑spot variability to diagnose under‑treatment, contamination, non‑uniform treatment, or material/lot shifts.
This method provides an image‑backed, quantitative surface‑readiness signal but does not by itself guarantee adhesion or print performance. Any pass/fail gates must be calibrated per material family + treatment recipe + ink/adhesive system by correlating D7490 outputs to your downstream KPI.
We hope this guide showed you how to apply surface science in the Semiconductors industry.
Now we’d like to turn it over to you:
Feel free to leave a comment below—we’d love to hear from you.
Start with water contact angle after each clean and prime step, since it shows residue and priming level quickly. Add surface free energy when adhesion fails or you change a primer or adhesive. Use surface tension for wet chemistries, and sliding angle for topcoats. Our contact angle and surface energy guides explain each method.
There is no single universal value. The right limit depends on the substrate, the clean chemistry and any primer. Even ASTM F22 does not define universal contact angle limits. Set your own limits from known good and known bad wafers, measure at a fixed time after the drop lands, and use several spots per wafer.
Measure contact angles of two or more probe liquids, usually one polar and one apolar, then calculate surface free energy from them. SEMI/ASTM D7490 describes this two liquid method for films and coatings. Our contact angle to surface energy calculator does the sums. Do not compare results across different models or probe liquid sets.
SEMI/ASTM D7490 covers surface free energy from contact angles. ASTM F21 and ASTM F22 describe visual atomizer and water break tests for hydrophobic films. ISO 25178 covers surface texture, not wetting. The Dropometer uses the sessile drop method, so run a correlation study before you report results under F21 or F22.
Yes. It measures contact angle and surface tension with no network connection, and drop images are captured and analysed on the phone. Internet access is needed once, to activate licences. The apps can run on a phone that your own IT team manages. Our secure site measurement page covers the setup.
The drop shape method was validated against a KRUSS DSA100E in two peer reviewed papers, one in Review of Scientific Instruments and one in Colloids and Surfaces A. Published contact angle accuracy is 0.35 degrees. Automatic edge and baseline detection gives the same reading from the same image. See our validation papers.
Yes. A Clemson group used it to track batch to batch variation in laser inscribed graphene electrodes. Splitting fabrication into batches with laser downtime cut contact angle variation. A University of Saskatchewan team used it as a reference check for their own setup in a carbon nitride film study. Browse more on our client citations page.
