Polymer resist materials for excimer ablation lithography

Suzuki, Kenkichi; Matsuda, Masaaki; Hayashi, Nobuaki

doi:10.1016/s0169-4332(98)00108-1

Cited by 17 publications

(12 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similar effects have been described for other polymers 24 ). At these relatively low fluences, the polymer could not be totally removed from the substrate. − …”

Section: 21 Designed Polymers Based On Commercial Polymersmentioning

confidence: 99%

Chemical and Spectroscopic Aspects of Polymer Ablation: Special Features and Novel Directions

2003

View full text Add to dashboard Cite

“…Similar effects have been described for other polymers 24 ). At these relatively low fluences, the polymer could not be totally removed from the substrate. − …”

Section: 21 Designed Polymers Based On Commercial Polymersmentioning

confidence: 99%

Chemical and Spectroscopic Aspects of Polymer Ablation: Special Features and Novel Directions

2003

View full text Add to dashboard Cite

“…The triazene polymers with -N=N-N< as structural unit revealed the most desirable properties, e.g., formation of high-quality films, stability to storing, and one-step synthesis. The requirements for the application of laser ablation as an alternative technique to classical photolithography are: sensitivity (etch rate/pulse at 100 mJ cm 2 !100 nm [335]); stability to "wet" acid etching; production of high-quality films by spin coating; and resolution of the ablation structures of 1 m. The TC polymers, novel polymers based on cinnamylidene malonic acid ester groups (CM polymers), and polyimide (PI) were tested for the previously described requirements.…”

Section: Introductionmentioning

confidence: 99%

Laser Application of Polymers

Lippert

2004

Polymers and Light

148

View full text Add to dashboard Cite

Laser ablation of polymers has been studied with designed materials to evaluate the mechanism of ablation and the role of photochemically active groups on the ablation process, and to test possible applications of laser ablation and designed polymers. The incorporation of photochemically active groups lowers the threshold of ablation and allows high-quality structuring without contamination and modification of the remaining surface. The decomposition of the active chromophore takes place during the excitation pulse of the laser and gaseous products are ejected with supersonic velocity. Time-of-flight mass spectrometry reveals that a metastable species is among the products, suggesting that excited electronic states are involved in the ablation process. Experiments with a reference material, i.e., polyimide, for which a photothermal ablation mechanism has been suggested, exhibited pronounced differences. These results strongly suggest that, in case of designed polymers which contain photochemically active groups, a photochemical part in the ablation mechanism cannot be neglected. Various potential applications for laser ablation and the special photopolymers were evaluated and it became clear that the potential of laser ablation and specially designed material is in the field of microstructuring. Laser ablation can be used to fabricate three-dimensional elements, e.g., microoptical elements.Keywords Laser ablation · Ablation mechanism · Photopolymers · Polyimide · Spectroscopy This was not always true, of course. For many years, the laser was viewed as "an answer in search of a question". That is, it was seen as an elegant device, but one with no real useful application outside of fundamental scientific research. In the last two to three decades however, numerous laser applications have moved from the laboratory to the industrial workplace or the commercial market. Lasers are unique energy sources characterized by their spectral purity, spatial and temporal coherence, and high average peak intensity. Each of these characteristics has led to applications that take advantage of these qualities: -Spatial coherence: e.g., remote sensing, range finding and many holographic techniques. -Spectral purity: e.g., atmospheric monitoring based on high-resolution spectroscopies. -and of course the many other applications in communication and storage, e.g., CDs.All of these high-tech applications have come to define everyday life in the late twentieth century. One property of lasers, however, that of high intensity, did not immediately lead to "delicate" applications but rather to those requiring "brute force". That is, the laser was used in applications for removing material or heating. The first realistic applications involved cutting, drilling, and welding, and the laser was little more advanced than a saw, a drill, or a torch. In a humorous vein A.L. Schawlow proposed and demonstrated the first "laser eraser" in 1965 [4], using the different absorptivities of paper and ink to remove the ink without damaging the und...

show abstract

“…Laser micromachining has, of late, become a very popular tool for fabricating 3D structures in various materials including ceramics [9], glasses [10] and polymers [11][12][13]. In particular, excimer laser ablation of polymers has found many practical applications.…”

Section: Introductionmentioning

confidence: 99%

Patterning, electroplating and removal of SU-8 moulds by excimer laser micromachining

Ghantasala

Hayes

Harvey

et al. 2001

J. Micromech. Microeng.

View full text Add to dashboard Cite

The ablation characteristics of the SU-8 photoresist (spun on Si wafers) under 248 KrF excimer pulsed laser radiation have been studied. The variation of etch rate with fluence has been investigated in the range 0.05-3.01 J cm −2 . The threshold fluence for ablation of SU-8 is measured to be about 0.05 J cm −2 . The etch rate of SU-8 is found to be higher than that of polyimide (previously reported) under similar conditions. We have investigated the effects of different prebake temperatures (90, 110, 120 and 200 • C) on ablation characteristics, which are found to be similar for all temperatures. The effect of increasing the number of laser shots (from 10 to 10 000) has been examined at different fluences in order to understand the etch-rate variation near the 'end of film' stage of ablation. The results of our analysis using scanning electron microscopy, profilometry and optical microscopy reveal the very smooth morphology of the etched surfaces with no significant debris, no noticeable damage to underlying silicon and the gradual build-up of a carbonaceous film outside and around the etch pits. We find SU-8 very suitable for excimer ablation lithography and have demonstrated this by patterning a gear structure in an SU-8 resist layer with an aspect ratio of 4.5. For the first time, we have shown that the laser micromachining technique has the potential to cleanly remove SU-8 after electroplating a microstructure with copper.

show abstract

Polymer resist materials for excimer ablation lithography

Cited by 17 publications

References 10 publications

Chemical and Spectroscopic Aspects of Polymer Ablation: Special Features and Novel Directions

Chemical and Spectroscopic Aspects of Polymer Ablation: Special Features and Novel Directions

Laser Application of Polymers

Patterning, electroplating and removal of SU-8 moulds by excimer laser micromachining

Contact Info

Product

Resources

About