Spun layers

Polymeric surface treatments are applied in similar fashion, namely spin-coating from a low-concentration solution of the polymer in organic solvent, e.g. 0.1% (w/w) polymer in toluene. Spin conditions can vary widely but, as reported by 3M [30a], 500 rpm for 20 s then 2000 rpm for 40 s provides 100 A thick dry polymer films on smooth dielectrics with good surface quality and contact-angle uniformity. Spun layers are typically air-dried for several hours, or dried at an elevated temperature of 110-130 °C for 30 min in an oven or 5 min on a hot plate. These materials are typically not rinsed after they are baked, because the homopolymer version would redissolve, removing almost all of the polymer. In a recent report from Fris-bie s group, in collaboration with 3M, device oxides were intentionally roughened... 

The stress-induced crystallization influences the ability to sustain the stress of deformation occurring in the spin line. Optical micrographs of fluffs allow the assumption of different deformation or stress behavior of core and skin layers of spun fibers, as shown in Figure 13.1. The reason for this kind of yam break can... 

Subsequently, other RIE PCM materials were used. They were selected either for their RIE characteristics or the feasibility of the deposition process. A list of these systems is shown in Table I. During this period, Hatzakis (79) developed a two-layer wet etch PCM system for e-beam exposure. Basically, a PMMA copolymer is spun on PMMA, or vice... 

Figure 14. Resist images of the two-layer copolymer wet-etch PCM system. A 0.4-jjLm thick copolymer layer was spun on 1.4 pm of PMMA. (Reproduced with permission from Ref. 19.)...

TABLE V. Processing Steps for the Two-Layer Spun on RIE PCM System... 

Rothman (52) investigated the planarization of polyimide films over features tens of micrometers in size and separation. Bassous and Pepper (55) studied planarization of PMMA and AZ1350J over features pertinent to Si wafer processing. A mechanical stylus was used to determine the topography of the wafer and the corresponding surface variation of the resist thickness as shown in Figure 29 where a 1.7 - pm thick AZ1350J layer was spun on steps of different space and width combinations. 

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