| abstract |
The present invention relates to compositions and a method for electroless formation of alkaline-metal-free coatings on the basis of cobalt and composition of cobalt with tungsten and phosphorus, which have high resistance to oxidation and stability of electrical characteristics, when the Co—Cu system layer is used in IC chips. The composition of the electroless solution contains more than one reducing agents, one of which can catalyze the initial electroless deposition layer of cobalt on copper (called initiator), while the other maintains deposition of cobalt on the aforementioned initial layer as the process is continued. Small amount (100-5000 ppm) of elements from the initiator also builds into the electroless film, which is expected to further improve the barrier properties of the resultant film compared to the deposition bath without initiator. Such coating may find application in semiconductor manufacturing where properties of deposited films and controllability of the composition and physical and chemical characteristics of the deposited films may be critically important. |