Fabrication of metal patterns on PET by conformal contact method

초록

From last times, fabrication of metal patterning is achieved by photolithography using photoresist, and etching or deposition[1]. And Nano-imprint lithography(NIL), metal transfer printing, soft lithography, micro-contact printing are used as simple tools such as molds, stamps, press, heating[2]. Recently, thin metal transfer on flexible film, like polyethylene terephthalate(PET), is interest things in many people. It can be applied to display panel or electronics, then short process step and complexity is most important to apply industry in reasonable process cost and speed. A lot of papers are discuss about method of metal transfer, for example heating or roller-pressing that has much loading force[3], but it cause excessive stress to patterns. For more easy transfer, anti-adhesive layer is formatted under metal, Cu, Ag, Au or Al. In general, Self assembled monolayer(SAM), toluene, CF4 are applicated in anti-adhesive layer[1, 2, 3]. Among the rest, Au is used in many experiment to pattern transfer because it has low surface energy[2, 3, 4, 5]. In this work, we describe the method that Ag patterns can be transfer to PET film through conformal contact. We are applicated only conformal contact to transfer Ag metal without other excessive force. And we use METAX solution to anti-sticking layer, primally. Fig. 1 shows the fabrication procedures of the sample. The polydimethylsiloxane(PDMS) is used in molds to transfer Ag metal and that fabricated on 10, 50, 100, 150 um line width patterned substrate were deposited by spin coating to anti-adhesive layer. Condition of spin coating is 10sec at 500rpm in first step, 30sec at 2000rpm in second step. Line patterns using AZ1518 and AZ9260 photoresist were fabricated by MJB4 aligner(SUSS), and anti-adhesive layer using METAX fz-610(Kanto Kasei). METAX has 40% fluorine, and it makes extreme hydrophobic layer. Anti-adhesive layer made by spin-coating, easily. Low surface energy of METAX is shown in Fig. 2 and Fig. 3. Fig. 2(a)