3D micro and nanostructuring of an epoxy based resist by electron beam lithography (original) (raw)

An advanced epoxy novolac resist for fast high‐resolution electron‐beam lithography

Aspects of the formulation of a highly sensitive cresol epoxy novolac-based chemically amplified negative resist ͑epoxy resist, EPR͒ and optimization of critical process parameters for high-resolution electron-beam lithography are reported. The bulk resist sensitivity ͑E 80 , dose for 80% thickness retention͒ is 0.9 C cm Ϫ2 at 40 kV. The effect of postapply bake and postexposure bake on resist sensitivity, contrast, and resolution are investigated and optimized for lithography up to the 0.1 m regime. The resist process is characterized by a good exposure dose latitude and relevant insensitivity to the variation of thermal processing conditions. Postexposure bake temperature variations in the 90-130°C range cause minimal change in sensitivity but remarkable change in contrast. Due to this behavior the resist process is not described satisfactorily by the reaction kinetic models commonly used to characterize chemically amplified resists of different chemistry.

Aqueous base developable epoxy resist for high sensitivity electron beam lithography

2000

Aqueous base developable, chemically amplified negative resists, based on epoxy chemistry are introduced and evaluated for high resolution, high speed e-beam lithography. These resists are formulated using partially hydrogenated poly(hydroxy styrene) and epoxy novolac polymers and they do not suffer from thermal instability of unexposed regions during processing. Degree of hydrogenation controls the aqueous base solubility and micro phase separation phenomena. Reduction of edge roughness compared to the pure epoxy systems is observed whereas the absence of swelling phenomena allows lithography up to 100 nm regime.

Electron beam lithography at 10keV using an epoxy based high resolution negative resist

Microelectronic Engineering, 2007

The behaviour of a new epoxy based resist (mr-EBL 6000.1 XP) as a negative resist for e-beam lithography is presented. We demonstrate that it is possible to define sub-100 nm patterns when irradiating thin (120 nm) layers of resist with a 10 keV electron beam. The dependence of resolution and remaining thickness on electron dose, electron energy and photo acid generator (PAG) content is determined. After the electron beam lithography process, the resist is used as a mask for reactive ion etching. It presents a good etch resistance, that allows transfer of patterns to the substrate with resolution below 100 nm.

Aqueous base development and acid diffusion length optimization in negative epoxy resist for electron beam lithography

44th International Conference on Electron Ion and Photon Beam Technology and Nanofabrication (EIPBN), 2000

A new aqueous base developable, chemically amplified negative resist based on epoxy chemistry is evaluated for high-resolution, high-speed e-beam lithography. This resist is formulated using partially hydrogenated poly͑hydroxy styrene͒ and epoxy novolac polymers. Degree of hydrogenation controls the aqueous base solubility and microphase separation phenomena. Reduction of edge roughness compared to the pure epoxy systems is observed whereas the absence of swelling phenomena allows lithography up to 100 nm regime and a sensitivity of 4-8 C/cm 2 at 50 keV. The diffusion coefficient has been evaluated both from high-resolution line and dot exposures and it is found to be 5ϫ10 Ϫ14 cm 2 /s for the optimal thermal processing conditions selected.

Development of inorganic resists for electron beam lithography: Novel materials and simulations

2004

CHAPTER 2. DEVELOPMENT OF SINGLE COMPONENT METAL-ORGANIC PRECURSORS FOR HIGH RESOLUTION ELECTRON BEAM LITHOGRAPHY 36 2.1. INTRODUCTION 36 2.2. METAL-ORGANIC PRECURSORS 39 2.3. MATERIALS AND METHODS 42 2.4. RESULTS AND DISCUSSION 45 2.4.1. Hydrolytic stability 45 2.4.2. Electron beam degradation 49 2.4.3. Electron beam response curve 54 vii 2.4.4. Enhancement of sensitivity using pre-exposure thermal baking 2.4.5. Precursor etch studies 2.4.6. Electron beam patterning: single layer imaging 2.4.7. Electron beam patterning: bilayer imaging 2.5. SUMMARY AND CONCLUSIONS CHAPTER 3. ELECTRON BEAM LITHOGRPAHY USING HIGH ATOMIC NUMBER METAL-ORGANIC PRECURSORS 3.1. INTRODUCTION 3.2. MATERIALS AND METHODS 3.3. RESULTS AND DISCUSSION 3.3.1. Dual and multicomponent precursor stability 3.3.2. Consequences of high atomic number species in an electron beam resist 3.3.2.1. Effects of high atomic number species in dual component systems 3.3.2.2. Effects of high atomic number species in multi-component systems 3.3.2.3. Effects of dual processing 3.3.3. Enhancement of etch characteristics through incorporation of high atomic number atoms 3.3.4. Electron beam patterning 3.4. SUMMARY AND CONCLUSIONS CHAPTER 4. DEVELOPMENT OF AN ALTERNATIVE INORGANIC ELECTRON BEAM RESIST: ENHANCING THE ELECTRON BEAM SENSITIVITYOF HYDROGEN SILSESQUIOXANE (HSQ) 4.1. INTRODUCTION 4.2. MATERIALS AND METHODS 4.3. RESULTS AND DISCUSSION 4.3.1. Processing delay effects 4.3.2. Enhancing the electron beam sensitivity of HSQ: dual processing approach 4.3.3. Enhancing the electron beam sensitivity of HSQ: sensitizer catalyzed imaging approach 4.3.3.1. Effect of Loading Sensitizers into HSQ Solutions on Storage Stability 4.3.3.2. Enhanced electron beam imaging with a photodecomposable base 4.3.3.3. Enhanced electron beam imaging with a photobase generator 4.4. SUMMARY AND CONCLUSIONS viii CHAPTER 5. CONSEQUENCES OF HIGH ATOMIC NUMBER SPECIES AND NANOPARTICLES IN AN ELECTRON BEAM RESIST: A MONTE CARLO STUDY 5.1. INTRODUCTION 5.2. MONTE CARLO SIMULATION PROCEDURE 5.3. VALIDATION OF SIMULATIONS 5.4. RESULTS AND DISCUSSION 5.4.1. Effects of high atomic number species 5.4.1.1. Effects of film densification 5.4.

Epoxide functionalized molecular resists for high resolution electron-beam lithography

Microelectronic Engineering, 2008

Chemically amplified resists would be a preferred option to non-amplified resists such as PMMA or ZEP for electron-beam lithography because of their much higher sensitivity and therefore faster write times, but are resolution limited compared to non-amplified resists due to photoacid diffusion. A chemically amplified molecular resist based on epoxide polymerization (4-Ep) has been developed that simultaneously has resolution of 35 nm half-pitch, sensitivity of 20 lC/cm 2 , and line edge roughness (3r) of 2.3 nm. The resist combines the performance advantages of both a molecular and polymeric resist. The extensive cross-linking effectively limits photoacid diffusion during resist processing, thus allowing for high resolution.

Computer simulation of resist profiles at electron beam nanolithography

Microelectronic Engineering, 2010

In this paper, resist behavior peculiarities in nanolithography is studied. Experimental data for the development rate dependence on the exposure dose is presented and used for numerical simulation of the developed profiles at electron beam nanolithography (EBL). These data concerns the most important nanolithography organic resist – polymethyl methacrylate (PMMA), chemically amplified resist CAMP6 and for the inorganic resist hydrogen silsesquioxane (HSQ). For a study of the nonlinear resist behavior during the development process, simulated resist profiles in the case of delay effect for penetration of the developer in the fresh resist material are discussed. The results are obtained using a universal approach for computer simulation of predicted profiles. It is concluded that such an effect will decrease the average rate of development and could be observed only in the side wall shape of the developed profile.