| 학회 | 한국재료학회 |
| 학술대회 | 2014년 봄 (05/15 ~ 05/16, 창원컨벤션센터) |
| 권호 | 20권 1호 |
| 발표분야 | A. 전자/반도체 재료(Electronic and Semiconductor Materials) |
| 제목 | Investigation of Co and CoSi2 formed by two step annealing with Ti capping layer |
| 초록 | Silicide materials are used for contact materials and interconnects to reduce parasitic resistance. Among metal silicides, cobalt silicide has relatively low resistivity, high thermal stability. However, cobalt silicide reaction on side wall causes short circuit failures. To solve this problem, two step annealing process consists of cobalt-self aligned silicide process. Another problem is the degradation of contact resistance and thermal stability due to rough interface between CoSi2 and Si. The capping layer has been researched to overcome this phenomenon. In this paper, we investigated the effects of a Ti capping layer on the formation of a CoSi2 film using a two-step annealing process to prevent bridging phenomenon and increase thermal stability. The Co films were deposited on Si substrates using dicobalthexcarbonyltertbutylacetylene (C12H10O6(Co)2, CCTBA) with H2 reactant gas under optimized process window by a metal-organic chemical vapor deposition (MOCVD). Then the Ti capping layer was deposited on the Co film by in-situ electron beam evaporation. The two-step annealing process was carried out to form the CoSi2 phase. After the first annealing process for forming the Co2Si or CoSi phases, a selective etching was applied to remove remaining unreacted Co and the Ti capping layer using solution NH4OH + H2O2. The cobalt films and cobalt silicides were characterized using AES, FPP, XRD, TEM, SEM. The temperature of formation CoSi and CoSi2 phases with Ti capping layer were lower than that of CoSi and CoSi2 phase without Ti capping layer because Ti capping layer captured impurity in the interface and film, and protects the silicide from oxygen contamination during Co silicidation. The Ti capping layer also affected the formation of smooth and uniform CoSi2 films during the silicide reaction because the Ti capping layer interrupt the formation of CoSi2 {111} facets at the interface between the CoSi2 and Si substrate during silicidation. |
| 저자 | 김현정, 박진규, 전희영, 장우출, 송효석, 전형탁 |
| 소속 | 한양대 |
| 키워드 | cobalt; cobalt silicide; Ti capping layer; MOCVD |
