Laser chemical vapor deposition for microelectronics production

Abstract

Laser chemical vapor deposition (LCVD) is a new, but not widely applied process used to directly deposit metal in a pattern determined by a laser. The LCVD process is similar to that commonly used in focused ion beam (FIB) systems where the ion beam breaks the chemical bonds in an organometallic gas containing platinum resulting in platinum deposition. With LCVD, a laser is used to heat the surface and a superior organometallic gas is used to provide 100% pure metal depending on the substrate. The FIB process only provides 50% metal in its generated line traces and is extremely slow. The increased metal purity opens up the use of LCVD for a variety of microelectronic applications. This characteristic, combined with its increased speed, makes LCVD a viable candidate for a production process. The LCVD technique begins with the a vapor-phase carrier of the compound being deposited into a vacuum system containing the substrate. The substrate is then irradiated with laser light to initiate a pyrolytic chemical reaction, which leads to the deposition of the desired compound onto the substrate. In the present case of writing lines of gold on various substrates, the vapor phase carrier is dimethyl gold trifluoroacetylacetonate (DMGT). By directing the beam as desired, an electrical circuit is created. LCVD has great potential to substantially reduce the cost in high density electronic applications for aerospace and super computer systems.