Model 800E

A mask aligner is a photolithography tool that brings a patterned mask into alignment with a coated substrate and then exposes the resist with ultraviolet light. Mask aligners are used to transfer layer patterns in laboratories, pilot lines, and production environments where contact or proximity exposure is appropriate. Frontside and backside mask aligners support alignment to features on the top surface or to marks viewed through the substrate for double-sided processing.

The OAI Model 800E uses Advanced Beam Optics for exposure uniformity. The OAI Model 800E supports vacuum contact, hard contact, soft contact, and proximity exposure modes. The standard frontside configuration uses dual 1MP resolution GIGE CCD cameras. The standard backside configuration adds 2 additional cameras for a total of 4 cameras. The backside configuration also includes digital zoom and motorized backside optics focus. The OAI Model 800E supports substrates up to 8 inch square and masks up to 9 inch by 9 inch.^[6][4]

Mask aligners sit in the lithography portion of microfabrication after substrate preparation and photoresist coating, and before development and the pattern transfer step. The exposure performed on a mask aligner defines the resist image that will later guide etching, lift-off, plating, implantation, or deposition patterning. Backside-capable mask aligners are used when later process steps require registration between features on opposite faces of a substrate.

Mask aligners are used for patterning resist on substrates during device fabrication, packaging, sensor processing, and microsystem development. Frontside alignment supports ordinary layer to layer registration on the device surface. Backside alignment supports processes such as through-substrate features, cavity formation, membrane structures, and other flows that need alignment between opposite sides of a wafer or panel.