Greg Breyta

Experimental implementation of an adiabatic quantum optimization algorithm.

We report the realization of a nuclear magnetic resonance computer with three quantum bits that simulates an adiabatic quantum optimization algorithm. Adiabatic quantum algorithms offer new insight into how quantum resources can be used to solve hard problems. This experiment uses a particularly well-suited three quantum bit molecule and was made possible by introducing a technique that encodes general instances of the given optimization problem into an easily applicable Hamiltonian. Our results indicate an optimal run time of the adiabatic algorithm that agrees well with the prediction of a simple decoherence model.

Investigation of pattern wiggling for spin-on organic hardmask materials

Semiconductor manufacturing technology is currently undergoing a transformation from immersion photolithography to double patterning or EUV technology. The resultant resist dimensional size and height shrinks will require improved pattern transfer techniques and materials. Underlayer (UL) processes which include chemical vapor deposition (CVD) and spin-on application play a very important role in various chip manufacturing integration schemes. A pattern wiggling problem during substrate etch has arisen as a critical issue when pattern dimensions shrink. CVD processes have shown better pattern transfer performance than spin-on processes but at higher cost and process complexity along with difficulty in obtaining planarization and good gap fill. Thus spin-on process development has received increased attention recently as an attractive alternative to CVD processing. In this work we focus on elucidating the mechanism of UL wiggling and have synthesized materials that address several hypothesized mechanisms of failure: hydrogen content, modulus, film density, charge control unit type and thermal resistance. UL materials with high thermal resistance additionally provide the ability to expand the applicability of spin-on approaches. Material properties and wiggle failure test results will be discussed.

Spin-on organic hardmask for topo-patterned substrate

Carbon rich hard mask underlayer (UL) material deposition has become inevitable process in all advanced lithography applications. UL processes which include chemical vapor deposition (CVD) and spin-on UL play a very important role for pattern transfer from patterned thin photoresist to the substrate. UL materials must satisfy several requirements, which have become more demanding with device shrinkage and increasing device complexity (FinFET, 3D integration). The most important properties of next generation UL materials are superior wiggle resistance, etch controllability, thermal resistance, planarization, and gap filling performance. In particular, planarization and gap fill properties of UL material for application on topo-patterned substrate are receiving much attention recently. CVD processes generally give better wiggle performance and thermal resistance, but poorer planarization and gap filling performance than spin-on UL processes. In addition, Cost of Ownership (CoO) of CVD process is higher than that of a spin-on UL process. Therefore spin-on organic hard mask (OHM) process has been investigated as an attractive alternative to CVD processing. In this paper, we focus on an investigation of key properties of spin-on UL materials for achieving good planarity and gap filling performance on topo-patterned substrate. Various material properties such as solution viscosity, glass transition temperature (Tg), and film shrinkage ratio were evaluated and correlations between these properties and planarization were discussed.

Hexafluoroalcohol (HFA) containing molecular resist materials for high-resolution lithographic applications

Molecular glass resists have gained attention for the past decade as a potential platform for high resolution lithography. Several molecular resist materials based on the calix[4]resorcinarene system have been developed. Though this molecular system is very versatile, there are several challenges with the synthesis and processing of these materials. The difficulty to synthesize a monodipserse unit, the poor solubility in casting solvents and incompatibility with conventional developer are some noted challenges. We have addressed these issues by designing a new calix[4]resorcinarene resist material with hexafluro alcohol (HFA) units. The resist platform has been evaluated with e-beam and EUV lithography.

Development of KrF hybrid resist for a dual-isolation application

As an option to traditional positive or negative photoresist, hybrid resist has been developed to provide an alternative way to create small trench features, at the range of 20-60 nm, by generating with a single expose, with both positive and negative responses to TMAH developer in one resist layer. [1] Here we report the design and development of a series of frequency-doubling KrF hybrid resists for an Extremely Thin Silicon on Insulator (ETSOI) dual-isolation application for 20 nm node and beyond. The resist formulations were optimized in terms of photo-acid generators (PAGs), PAG loading level and polymers. The resulting KrF hybrid resists are compatible with conventional KrF lithography processes, including conventional illumination, binary masks and 0.26 N TMAH developer, to afford a spacewidth of 20-60 nm. The space CD can be controlled by means of formulation and process options, but is insensitive to expose dose and mask CD. On integrated wafers, the hybrid resists have demonstrated good lithography performance, including through-pitch CD uniformity, focus/expose process window, profile, LER and RIE behavior. This hybrid resist process has been used to fabricate initial development structures for high performance dual-isolation ETSOI devices.