TI, National Semiconductor (now owned by TI), Hitachi, are the 3 off the top of my head that i think of. you can also look at a data sheet and find the correct part number for military, or other very high reliability and extended temp and voltage range devices (as opposed to standard "consumer" grade devices). they are more expensive, but if you are looking at a very high reliability requirement, it's worth the extra money. if you use electrolytic capacitors in the circuit, they will probably fail long before even a consumer grade cmos chip will. you can, however look up electrolytic caps on Newark and Digi-key's websites, and search using lifetime as a search filter.