Highly resistive structures for integrated circuits and method of

Abstract

This invention is a process for making resistor structures having high stability and reliability characteristics. Process parameters are easily modifiable to adjust the resistivity of the structures. A layer of titanium nitride, which may contain certain impurities such as carbon, is deposited via chemical vapor deposition by pyrolization of an organometallic precursor compound of the formula Ti(NR.sub.2).sub.4 either alone or in the presence of either a nitrogen source (e.g. ammonia or nitrogen gas) or an activated species (which may include a halogen, NH.sub.3, or hydrogen radicals, or combinations thereof). The TiN film is then oxidized to create a structure that demonstrates highly stable, highly reliable resistive characteristics, with bulk resistivity values in giga ohm range. In a preferred embodiment of the invention, a predominantly amorphous titanium carbonitride film is deposited on an insulative substrate in a chemical vapor deposition chamber. A layer of titanium is then deposited on top of the titanium carbonitride film. The titanium layer is then patterned with photoresist. The exposed titanium is then etched with a reagent that is selective for titanium over titanium carbonitride (HF, for example, has better than 10:1 selectivity) so that the etch essentially stops when the titanium carbonitride film is exposed. The exposed titanium carbonitride film is then oxidized to achieve the desired resistivity.