Stripping of photoresist on silicon wafer by CO2 supercritical fluid

Efficient stripping of photoresist on metallized wafers by a pause flow of supercritical fluid

“…In a previous study on the SCF stripping of PR on aluminum substrates, there was only an approximate recovery of 70% obtained despite collection for 45 min [19]. This low recovery may result from improper SCF conditions, which were formerly designed to strip another type of PR on silicon oxide substrate.…”

“…In a previous study, we used factorial experimental designs to optimize the stripping of commercial PR on silicon oxide and aluminum layers, and to determine the basic effects of processing variables on the ratio of recovery [19]. Progression of the lab-scale representation of SCF removal to commercial apparatus requires a full understanding of fluid flow and mass transport within an extractor.…”

Preparation of polypropylene (PP) composite foams with high impact strengths by supercritical carbon dioxide and their feasible evaluation for electronic packages

“…Furthermore, the surface tension of supercritical fluids is nearly zero just like the gas and therefore they can easily permeate into the multicellular materials. Due to the excellent physical performances, supercritical fluids have been readily utilized for purification and separation of power generation [2], fibre dyeing [3], preparation of micro-and nanoparticles [4], treatments of waste waters [5], polymerization media of monomers [6], organic compounds [7], cleaning of wafer surfaces [8], and drying [9]. Carbon dioxide (CO 2 ) is a good supercritical fluid for various applications because of its low toxicity, eco-compatibility, non-inflammability, high equilibrium concentration, its low critical point (critical temperature: 31.7 C; critical pressure: 1069.8 psi), and high diffusivity for polymers [10].…”

Plasma-assisted supercritical carbon dioxide removal process for photoresist stripping applications

“…This wet process thus needs to overcome the lower yield caused by the wettability of the cleaning solution in the trench at such length scales. Several methods of photoresist cleaning have been reported in the literature, including traditional wet process (Heyns et al, 1999), ozone/DI water (Abe et al, 2003;Clark and Christenson, 2005), oxygen plasma (Metselaar et al, 1994), UV/O 3 (Choi et al, 2003) and supercritical carbon dioxide (SCCO 2 ) cleaning (Chen et al, 2006;Hoggen et al, 2004;King and Williams, 2003;Rubin et al, 1999). Among them, the SCCO 2 process is the most likely solution which can meet the abovementioned requirements, as well as environmental considerations.…”

“…Various applications of SCF in IC manufacturing, www.elsevier.com/locate/jcice including wafer cleaning, film deposition, photoresist stripping, drying, and particulate removal have since been introduced (King and Williams, 2003). In a recent paper by Chen et al (2006), factorial experimental design was used to optimize the photoresist stripping process by factors of temperature, pressure of CO 2 , static, and dynamic operation time. However, the mechanism for the removal of hard-baked photoresist remains incomplete.…”