PSL Spheres, laser particle counters, KLA-Tencor SP1, KLA-Tencor SP2

Applied Physics, Inc.


Applied Physics, Inc.

Call Us: 1-720-635-3931

Wafer Size Standards

Clean Room Foggers

Ultrapure Foggers

PSL Spheres, Silica Particles

Aerosol Product Information

PSL Spheres and Polystyrene Latex Beads

Polystyrene Latex spheres are produced as NIST Traceable polymer beads from 20 nanometers to 160 microns. Polystyrene Latex spheres are highly accurate, size standards used to calibrate size accuracy of laser particle counters. PSL spheres are suspended in a DI Water solution at a specific size in an atomizer or nebulizer, which is used to create a particle aerosol with a narrow size distribution for calibration of laser particle counters.

PSL Spheres, Polystyrene Latex beads - Request a Quote

Polystyrene Latex Beads

Applied Physics provides PSL Spheres and polystyrene latex beads are size standards used for aerosol instrument calibration. Companies, such as KLA-Tencor SP1, KLA-Tencor SP2, TopCon, ADE and Hitachi produce Wafer Inspection Systems, also referred to as SSIS or Scanning System Inspection Systems. PSL spheres and polystyrene latex beads are provided in sizes from 20nm to 5 microns to calibrate the size response curves of the respective wafer inspection systems and laser particle counters. PSL Spheres from 20nm to about 3 microns are typically used to calibrate the size response of laser particle counters. PSL spheres are also used to create PSL Wafer Standards and Particle Wafer Standards calibrate size response of KLA-Tencor SP1, KLA-Tencor SP2, etc. Polystyrene latex beads are also used in studies to generate particle size response curves for laser particle counters and such. PSL Spheres and polystyrene latex beads are spherical and man made to specific diameters, while Process Particles are non uniform in size and shape, and come in a variety of process particles, as discussed in the last section of this page.

Polystyrene latex beads can be ordered by calling Applied Physics at 720-635-3931.

Wafer Inspection Systems, referred to as Scanning Surface Inspection Systems, SSIS, most notably from KLA-Tencor and Hitachi, are calibrated using PSL Wafer Standards, which are Prime Silicon wafers deposited with PSL spheres. The SSIS is used to inspect the cleanliness of 300mm, 200mm, 150mm wafer surface; either bare silicon or a film deposited, wafer surface. The SSIS can identify the X/Y location of the PSL spheres and particles and describe the size of each defect as well as the overall count on the wafer surface. KLA-Tencor wafer inspection systems, such as Tencor 6200, 6420 and the KLA-Tencor SP1, KLA-Tencor SP2 and KLA-Tencor SP3, are used through out the semiconductor industry for this application. Topcon has the 3000, 5000 and 7000 series Wafer Inspection Systems. Estek, ADE, Aeronca and Hitachi also provide a variety of wafer inspection systems. Nearly every SSIS produced today is now able to detect at 30nm or better particle size sensitivity. PSL Spheres are used to represent the particles on the wafer surface. Applied Physics offers PSL Sphere sizes from 20 nm to 160 microns for size calibration, HEPA Filter tests, etc. PSL Spheres can be ordered by calling Applied Physics at 720-635-3931.

PSL Spheres are used with PSL Wafer Deposition Systems to produce PSL Wafer Standards, also referred to as Particle Wafer Standards. In either case, after the PSL Wafer Standard is produced, it is then placed on a wafer inspection system and scanned by a single laser SSIS or dual laser SSIS. The actual PSL size response is compared to the SSIS size response. If the two peaks do not match, the SSIS must be calibrated.

Pre-mixed, high concentration PSL Spheres are for 2300XP1 systems, 2300 NPT-1 systems, 2300NPT-2 and M2300G3 wafer deposition systems.

Un-mixed PSL Spheres, generally in 1% concentration.
The pre-mixed PSL Spheres come in a 50ml bottle, mono-disperse in size (1 size distribution), and are provided from about 47nm to 950nm in size. This PSL solution is poured directly into the nebulizer or atomizer vessel. Pre-mixed is a convenient way of purchasing the polystyrene latex beads, since all the dilution has been accomplished in a very uniform manner, no muss, no fuss, permitting the user to not deal with mixing the polystyrene latex beads using beakers, DI water and ultrasonic trays.

The un-mixed PSL material is provided in a 15ml bottle, mono-disperse in size (1 size distribution), and usually in a 1% concentration. These PSL Spheres are provided in a broad range of sizes, but for our purposes, from 20nm to 4um in size. The PSL material must be mixed to the proper dilution or it will be to concentrated or too weak to provide effective results when trying to deposit by one of the above PSL Wafer Deposition Systems.

Process Particles > Process Particles are provided as Si, SiO2, Al2O3, TiO2, Si3N4, Ti, W, Cu, Ta particles in a DiH2O solution. The particles are of a specific refractive index, different than polystyrene latex beads. Particles are non-uniform in size and shape, provide a different refractive index than PSL Spheres. Particles can be used to generate a true size response curve for a specific type of particle; or can be used to deposit on a wafer surface to challenge the cleaning efficiency of a WET Bench. The particles are offered in the types described above, and are provided in a DI water solution, 100ml. The particles are poly-disperse in size (many size peaks in the same bottle). One can order specific size ranges of particles from 40nm to 200nm, 200nm to 500nm and 500nm to 1um in size.