SU-8 has been widely used in a variety of applications for creating structures in micro-scale as well as sub-micron scales for more than 15 years. One of the most common structures made of SU-8 is tall (up to millimeters) high-aspect-ratio (up to 100:1) 3D microstructure, which is far better than that made of any other photoresists. There has been a great deal of efforts in developing innovativ...

By exploiting the thermoplastic and photosensitive nature of SU-8 photoresists, different types of hierarchical pillar arrays with variable aspect ratios are fabricated through capillary force lithography (CFL), followed by photopatterning. The thermoplastic nature of SU-8 enables the imprinting of micropillar arrays with variable aspect ratios by CFL using a single poly(dimethylsiloxane) mold,...

Two advanced processes have been developed for fabricating ultra thick and ultra high aspect ratio (HAR) microstructures. One is the SU-8 based deep x-ray lithography (SU-8 based DXRL) process which uses the normal deep x-ray beam to expose the negative SU-8 resist. Another one is wave length shifter(WLS) based Ultra deep x-ray lithography (WLS-UDXRL) process which uses special ultra deep x-ray...

A representative fabrication processing of SU-8 photoresist, Ultraviolet (UV) lithography is usually composed of spin coat, soft bake, UV exposure, post exposure bake (PEB), development and optional hard bake, etc. The exposed region of SU-8 is crosslinked during the PEB process and its physical properties highly depend on UV exposure and PEB condition. This work was initiated to investigate if...

Adhesive strength between microsized SU-8 components and Si substrate is evaluated to clarify effects of heat curing. Micro-sized cylindrical shape is employed as a micro-sized adhesive test specimen to properly apply the load onto the specimen and to simply convert applied load to stress. Micro-sized cylindrical specimens of epoxy type photoresist, SU8, were fabricated on a silicon wafer using...

We consider the unification of gauge, Higgs as well as the matter fields in a 6D N= 2 supersymmetric SU(8) gauge theory. The gauge symmetry SU(8) is broken down to SU(4)× SU(2)L × SU(2)R × U(1) in 4D through T 2/Z6 orbifold compactification, and the theory is reduced to 4D N = 1 supersymmetric Pati-Salam model. The electroweak Higgs fields as well as the third family of fermions are unified in ...

The requirements for better control, linearity, and uniformity of critical dimension (CD) on photomasks in fabrication of 180 and 150 nm generation devices result in increasing demand for thinner, more etching durable, and more sensitive ebeam resists. Novolac based resists with chemical amplification have been a choice for their sensitivity and stability during etching . However, difficult CD ...

A non-Brownian suspension of micron scale rods exhibits reversible shear-driven formation of disordered aggregates resulting in dramatic viscosity enhancement at low shear rates. Aggregate formation is imaged using a combined rheometer and fluorescence microscope. The size and structure of these aggregates are found to be a function of shear rate and concentration, with larger aggregates presen...

Under an assumption that an S4 flavor symmetry is embedded into SU(3), a lepton mass matrix model is investigated. A Frogatt-Nielsen type model is assumed, and the flavor structures of the masses and mixing are caused by VEVs of SU(2)L-singlet scalars φu and φd which are nonets (8+1) of the SU(3) flavor symmetry, and which are broken into 2+3+3 and 1 of S4. If we require the invariance under th...

We consider the unification of gauge, Higgs as well as the matter fields in a 6D N= 2 supersymmetric SU(8) gauge theory. The gauge symmetry SU(8) is broken down to SU(4)× SU(2)L × SU(2)R × U(1) in 4D through T 2/Z6 orbifold compactification, and the theory is reduced to 4D N = 1 supersymmetric Pati-Salam model. The electroweak Higgs fields as well as the third family of fermions are unified in ...