PR1-4000A Positive Resist PR1-4000A is a positive tone photoresist designed for 365 or 436 nm wavelength exposure, using tools such as wafer steppers, scanning projection aligners, proximity printers and contact printers. PR1-4000A excels in applications when superior adhesion is required. Use of adhesion promoters, such as HMDS is not recommended with PR1-4000A. These are the advantages of PR1-4000A over other resists: - superior resolution capability - fast photospeed - superior linewidth control due to suppression of reflective notching - substrate adhesion which is superior to that of any commercial positive resist - ease of removal after RIE process - shelf life exceeding 1 year at room temperature storage. The formulation and processing of PR1-4000A were designed with regard to occupational and environmental safety. The principal solvent in PR1-4000A is 1-methoxy-2-propanol and development of PR1-4000A is accomplished in a basic water solution. Properties ♦ Solids content (%): 36-38 ♦ Principal solvent: 1-methoxy-2-propanol ♦ Appearance: light yellow liquid ♦ Coating characteristic: very uniform, striation free ♦ Film thickness information: Coating spin speed, 40 s spin (rpm) Film thickness after 100°C oven bake for 15 min (nm) 800 7600-8400 2000 4680-5160 3000 3800-4200 4000 3268-3612 5000 2848-3152 ♦ Sensitivity (mJ/cm² for 1 μm thick film): 365 nm exposure wavelength: 70 436 nm exposure wavelength: 40 ♦ Guaranteed shelf life at 25°C storage (years): 2 Processing 1 Application of resist by spin coating at selected spin speed for 40 s. 2 Application of Edge Bead Remover EBR1 to bottom and edge of the coated wafer for 10 s, until 5 s before completion of spin cycle.