The Substrates, Surface Preparation Tools, and Storage Conditions That Define Carrier and Desiccator Selection
A carrier case or desiccator cabinet is specified by the substrate it holds. Diameter, material, cleanliness class, and susceptibility to atmospheric moisture all determine which carrier format and which storage environment is appropriate. A carrier specification that matches a silicon wafer may not protect a sapphire or single-crystal substrate through the same handling sequence if the substrate geometry, surface sensitivity, or cleanliness requirement differs.
Substrate Characteristics That Drive Carrier Selection
MSE Supplies Single Crystals including sapphire, SiC, and oxide substrates in round and square geometries require carrier cases sized to their specific diameter and cassette configurations compatible with their thickness and notch geometry. Conductive glass substrates such as ITO and FTO slides are square rather than round and require membrane boxes or gel sticky carriers that immobilize them without applying pressure to the conductive coating, which is sensitive to abrasion from contact with polypropylene cassette fingers.
Surface Preparation and Cleaning Around Transport Steps
Wafer scribing tools produce cleaved or scribed sections from full wafers before they are loaded into individual carriers for transport between process stations. Scribing debris and particulates released at the cleave site must be removed before the substrate enters a carrier; cleanroom wipes rated for low particle generation and low ionic contamination remove loose debris without introducing fiber contamination from standard wipe materials.
Dry Storage Between Active Process Steps
Between process sessions, substrates removed from active tooling accumulate surface contamination from atmospheric moisture and particulates. A vacuum desiccator provides a sealed, low-humidity enclosure for storing cleaned substrates, photomasks, and reactive materials sensitive to moisture adsorption during idle periods. Desiccator volume and shelving configuration are matched to the substrate size and quantity being stored, with larger bulk desiccator cabinets serving as central storage and smaller units positioned at individual workstations for immediate access.
Carrier and desiccator selection is a substrate compatibility decision. The substrate format drives the carrier geometry, the scribing step drives the cleaning requirement before loading, and the moisture sensitivity of the substrate drives the storage environment specification. Addressing all three keeps the substrate surface in the state the next process step expects to find it. For an overview of all laboratory instrumentation and materials available from MSE Supplies, the Materials Science products hub covers the full catalogue across research categories.
Frequently Asked Questions
How do I pick the right single wafer carrier size?
Match the case to your wafer diameter. Single wafer carrier cases come in 1, 2, 3, 4, 6, 8 and 12 inch sizes, so 150 mm, 200 mm and 300 mm wafers each have their own case. Most sizes come in packs of 10, such as the 4 inch carrier case and the 2 inch case. For 300 mm wafers, see the 12 inch carrier case.
When should I use a 25 wafer carrier box instead of single cases?
Single cases keep each wafer apart, which suits individual samples and wafers that move on their own. A 25 wafer carrier box holds a full batch of same-size wafers, which suits batch processing and bulk storage. The 2 inch 25 wafer carrier box and the 4 inch version are sold as sets of 5 boxes.
What are membrane boxes for, and which size do I need?
Membrane boxes hold small, delicate parts such as diced chips, substrates, crystals and optics on a flexible membrane that keeps them in place when the lid is closed. Choose a box that fits your largest part with room to spare. Sizes run from the 38x38x17 mm box in packs of 12 up to the 300x300x50 mm box for large or multiple parts.
Do you have membrane boxes for static sensitive devices?
Yes. The static dissipative (ESD safe) membrane boxes, 38x38x17 mm in packs of 12, are made for parts that electrostatic discharge can damage, such as patterned device chips and sensors. Use them in place of standard membrane boxes when the parts carry circuits or other charge sensitive structures.
What is a vacuum release tray for?
Vacuum release trays are made for extremely fragile parts that could crack if gripped or pried off a sticky surface. The part rests on a membrane that holds it during handling, and applying vacuum under the tray releases it for pickup. The 2 inch and 4 inch vacuum release trays come in packs of 10.
How do I ask about an unlisted size or a larger quantity?
Send the wafer diameter or part dimensions and the quantity through the quote request page. To equip a cleanroom or fab with several sizes at once, use the bulk order request form and list each size and pack count.
