PSL Spheres, NIST SRM PSL Spheres and Process Particles

Wafer Inspection Applications

PSL Spheres & Processes Particles

Applied Physics provides PSL Spheres and Process Particles for your wafer inspection applications.  Companies, such as KLA-Tencor, TopCon, ADE, Hitachi use PSL spheres to calibrate the size response curves of the respective wafer inspection systems.  Many Semiconductor companies use Process Particles to generate particle size response curves for their wafer inspection tools, as well as process particles to challenge their WET Bench tools to see how efficient the WET Bench is at removing real particles under controlled conditions.  PSL Spheres 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.

PSL Spheres  Purchase PSL Spheres

Wafer Inspection Systems, also referred to as Scanning Surface Inspection Systems, (SSIS) are used to inspect the cleanliness of the wafer surface; either bare silicon or film deposited surface. The SSIS can identify the X/Y location of the particles and describe the size of each particle 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, SP2 and SPX, 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 40nm or better particle size sensitivity. PSL Spheres are used to represent the particles on the wafer surface. Applied Physics offers PSL sizes from about 40nm to 4um. The PSL Spheres can be ordered in three versions of use.

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 wafer is produced by one of these tools from VLSI, Brumley South, JSR, MSP, the wafer standard 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, low concentration for PSL deposition systems produced only by JSR, Brumley South and the old VLSI Standards PDS products.

Pre-mixed, high concentration PSL Spheres are for MSP 2300B, 2300C, 2300D, 2300XP1/XP2 and 2300 NPT-1 wafer 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 PSL Spheres, 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 PSL material 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  Purchase 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 PSL. 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.

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