SUNY Polytechnic Institute Colleges of Nanoscale Science and Engineering Master's Theses
Studying the Segregation Induced Resist Component Contribution to EUV Stochastic FailuresExtreme Ultraviolet (EUV) technology is necessary for chip manufacturing technology for finer circuits into many components for building faster and more energy-efficient chips. The EUV process utilizes a plasma light source that emits 13.5 nanometers in wavelength to create higher resolution chip circuit designs to transfer an aerial image at smaller dimensions for advanced process nodes at lower exposure doses. Chemically amplified resists have been recently commercialized as it benefits higher resolution chip circuit designs. However, one of the issues concerning EUV technology is that it can suffer from different types of stochastic defects due to photon shot noise, random inhomogeneities, and non-random inhomogeneities. This study investigates the potential non-random stochastic effects that exist in the multicomponent resist. In the multicomponent resist, self-segregation occurs, creating an inhomogeneous distribution leading to failures in the resist. We approached this problem by looking at previous models of the phase diagram to understand the system and energetic favorability of segregation. Throughout our experiments we explore balancing the ratios of solvent, polymer, and PAG and hoping to define the line where we reach the 2-phase region indicating we have reached segregation. First, we observed phase segregated regions using AFM through a spin coating method and a drop coat method. Then we approached the issue by analyzing the bulk liquid. Although we were unable to find the exact parameters where we cross the 2-phase region, through several formulations we have narrowed down the region that segregation occurs.
Magnesium Oxide Tunneling Current and Ferromagnetic Film CharacterizationMagnetic Tunnel Junctions are a very promising technology with the potential to replace numerous forms of computer memory a well as a wide range of other applications. Three novel studies are done demonstrating various aspects of MTJ design and manufacturing showing their importance in understanding device performance. First, a Vibrating Sample Magnetometer (VSM) study comparing Co40Fe40B20 and Co20Fe60B20 films of varying thicknesses between 0.6 nm and 3.2 nm is reported. Greater iron content is shown to increase the overall magnetic moment of the samples. Second, a Current in Plane Tunneling (CIPT) study is done showing the dependence Magnetoresistance (MR) has on the thickness of the MTJ free layer and the crystallinity of the active region of devices. A full MTJ device stack is developed, with free layer thicknesses from 0.6-1.75 nm and 1.5-3.3 nm creating a wedge profile on each sample wafer. CIPT shows a significant increase to MR with anneal, verifying the presence of the  crystal structure in post anneal samples using TEM. Third, Ta/Co40Fe40B20/MgO/Co40Fe40B20/Ta thin film metal-insulator-metal capacitors were developed to measure the tunneling effect and how it changes as a result of MgO thickness and CoFeB crystallinity. Devices were designed with: varied MgO thickness from 0.5 nm to 2 nm thick, with pre and post anneal CoFeB. Current-Voltage data was collected and device resistance was found to have a linear dependence on MgO thickness in the post anneal CoFeB/MgO/CoFeB samples. The uniformity of the IV data indicates potential for use monitoring devices during MTJ manufacturing.