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

Smoke Studies, Visualize Airflow, Clean Rooms

PSL Spheres and Polystyrene Latex Beads

Polystyrene Latex spheres are NIST Traceable, polystyrene latex beads from 20 nanometers to 160 microns; which are highly accurate, size standards with a narrow particle size distribution, suspended in a DI Water solution with a trace surfactant to minimize agglomeration. Polystyrene latex beads are used to create a particle aerosol to challenge the size accuracy of laser particle counters or to produce PSL Wafer standards.

PSL Spheres, Polystyrene Latex beads - Request a Quote

Polystyrene Latex Beads

Applied Physics provides PSL Spheres, polystyrene latex beads, as particle size standards for laser particle counter, size calibration. Wafer Inspection tools, such as KLA-Tencor Surfscan tools and the older Tencor Surfscan tools also require size calibration, which is accomplished by depositing polystyrene latex particles on prime silicon wafer, as PSL Wafer Standards. Tools such as the Tencor 6200, Tencor 6220, 6400 and 6420 are the Surfscan tools are generally calibrated from 100 nanometer to an upper size range of perhaps 3-5 microns; while the newere KLA-Tencor Surfscan tools, SP1, SP2, SP3, SP5, SPx are calibrated from 32 nanometers to perhaps 5 microns. Hitachi also has wafer inspection tools that are calibrate in the same manner, using polystyrene latex spheres deposited as PSL Wafer standards. Polystyrene latex beads are provided in sizes from 20nm to 10 microns to calibrate the size response curves of the respective wafer inspection tools; while PSL spheres from 20nm to about 5 microns are typically used to calibrate the size response of laser particle counters.

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

Although laser particle counters are less sophisticated than a wafer inspection tool, measuring size accuracy of particles in an airstream is most often based on a PSL, Polystyene Latex, particle size calibration. size accuracy of Wafer Inspection Systems, referred to as Scanning Surface Inspection Systems or SSIS, most notably from KLA-Tencor and Hitachi, are calibrated using PSL Wafer Standards, which are Prime Silicon wafers deposited with PSL spheres at specific sizes and narrow size distribution. The wafer inspection tools are used to inspect the cleanliness of 300mm, 200mm, 150mm wafer surfaces; bare silicon or film deposited, wafer surface. The SSIS can identify the X/Y location of the PSL spheres and particles, describe the size of each defect as well as summarize an overall particle 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 are provided as Silica nano-particles with a 10% concentration in a DiH2O solution. Silica particles have a similar refractive index to polystyrene latex beads, making silica nanoparticles quite useful for size calibration when calibrating the size accuracy of wafer inspection tools using a high powered laser. Silica particles generate a true silica size response curve for wafer inspection tools, as opposed to using polystyrene latex spheres to represent size for particles encountered in the production of device chips. Silica particles can be used to deposit on a wafer surface to challenge the cleaning efficiency of a WET Bench. Silica particles are provided in a 15ml bottle with 10% concentration, as opposed to PSL spheres, which are 1% concentration or less. Silica particles are monodisperse in size (one size peak) with sizes available from 40nm to 2um in diameter.