Use of photosensitive metal-organic precursors to deposit metal-oxides for thin-film capacitor applications.

摘要

Within the last 10 years, consumers have witnessed dramatic advances in the number, size and capability of portable electronic devices. Today a majority of the area on printed wiring boards is occupied by surface mounted discrete passive components and the effect passive components have on the cost, size, weight, and reliability of portable electronic devices is substantial. In order for the trends of size reduction, increased performance and lower cost to continue to continue, surface mount components will need to be replaced by integral passive devices which can be incorporated directly into the printed wiring board (PWB) substrate. One particularly interesting challenge is to identify materials and processes that are compatible with organic PWB substrates that can be used to fabricate such integral passives. In this area the production of capacitive structures is particularly difficult since the traditional dielectrics used for such purposes require high temperature processing.; The work presented in this doctoral thesis is centered on a novel method for direct patterning of metal oxides from metal-organic precursors. The proposed method uses ultraviolet light to create patterned metal oxide films at ambient temperatures, with no need of separate deposition and patterning steps. As a result, this method eliminates the need for costly patterning techniques that require the use of vacuum equipment. This is a low temperature process that satisfies the temperature requirements for packaging applications, and eliminates the need for costly vacuum processing.; Precursor compounds and the resulting oxide materials were evaluated in terms of their ability to satisfy a long list of material performance requirements. Investigation of the precursor decomposition mechanisms occurring during photochemical and thermal processing was carried out via Fourier transform infrared (FTIR) spectroscopy using a custom-made peak deconvolution program. A variety of analytical techniques were used to characterize the deposited oxide films and correlate the resulting film properties with the chosen processing method. Based on these experimental results, alternative precursor compounds were formulated and evaluated. These studies were able to delineate key precursor structure-property relationships and identify an alternative precursor compound with improve properties.