SBIR-STTR Award

Simulation of thin film growth is an essential aspect of developing new materials engineered to specific properties and defining the processing sequence required to produce the film. Software available to simulate such growth requires high end computer performance, and the programs are designed for use by experts in thin film growth who are interested in studying the mechanisms of nucleation and growth. Identifying processing parameters and control parameters suited to producing films is not a focus of these computer programs. Thus, the first issue is reducing the computational burden in simulation. The second issue is ease of use and suitability of display of the simulation in a timely manner for the user. AvXm proposes to demonstrate that the NanoModeler system as a thin film simulation system is suitable for enhancing the design of engineered materials and for developing process sequences for manufacturing the films. Important aspects of the NanoModeler system are the visual display, simple user interface, substrate design capability, archiving capability of simulations, and reduction of computational complexity. The unique combination of methods we have created represents a new approach to simulation not available presently on desktop level computers.

Benefits:
Rapidly simulate a film and exercise the parameters associted with its formation. Ease of development of the processes necessary to manufacture the film. Improved efficiency in materials use are significant, particularly where environmentally hazardous materials are considered. Control of the materials use and their disposal through a firm understanding of the film formation process leads to better control of waste and related residuals from the process of making the film.

Five objectives are proposed for this research. (1) In Phase I, MBE and PLD were explicitly included as possible processes in the user interface. Addition of gas cluster ion beam (GCIB) process to the Nanomodeler is proposed to provide simulation possibilities for complex oxides such as thermodchromics and high temperature superconductors. (2) However, to move to the microscale, a coherent and physically well-grounded approach must be devised that allows a transition from atomic/molecular scales to nanometer scales to micron scales, because grain sizes of importance cover the range from nanometers to microns to millimeters. Microstructure prediction based on atomic models is not practical because of the number of atoms involved, requiring transition schemes that naturally phase-out atomic effects and introduce micro-effects and collective phenomena associated with long range defects and grain distributions. (3) Interactivity requirements of the software pose serious user problems when accessed via the Internet because of data transmission problems (bandwidth limitations). Interfacing to Infoscribe archiving software, and developing file access algorithms that allow full interactivity with Infoscribe file system and formats will be pursued. (4) Locating versions of Nanomodeler is user facilities is anticipated to allow feedback as to functionality, display, files, ease of use, bugs, archiving, process design concerns such as recipes, sensors, and inputs of control variables. (5) Removal of thin films will be considered in the context of the discrete methods applied in Nanomodeler.

Benefits:
Major benefits from this research are: time savings from simpler user interface; greater understanding and control over processes, yielding better and cheaper products; and savings resulting from 'virtual research' as compared with experimental 'real' research. Savings in resources achieved by application of the software carries into the time needed to produce new materials by shortening it considerably, a great advantage technically and economically.