A Study on Property Improvements of Sputtered Copper Films Using Glass-Forming Film and Oxide

• Main Authors: Yia-Ling Chou, 周雅玲
• Other Authors: J. P. Chu
• Format: Others
• Language: en_US
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/04724297276028792391

碩士 === 國立臺灣海洋大學 === 材料工程研究所 === 95 === In this study, sputtered Cu film properties have been improved using a glass-forming (Zr45.7Cu32.2Al14.3Ni7.8) as the barrier layer and doping with small amounts of oxygen. For this Zr-based film alone (hereafter called the Zr layer), it shows nanocrystalline structure (as-deposited) transformed into a fully amorphous structure and then to crystalline structure upon annealing at high temperatures, consistent with a previous study. For the barrier studies in the Cu/Zr/Si, the maximum stable temperature where the film resistance is not changed are 540□C, 530□C, 520□C, 540□C and 550□C for barrier layers in thickness of 20 nm, 10 nm, 4 nm, 1 nm and 0.3 nm, respectively. However, the copper silicides are formed (as shown in XRD results) before the increases in resistance. In TEM results, the copper silicides are present for the barrier in thickness of 0.3 and 1 nm (called Cu/Zr(0.3 nm)/Si and Cu/Zr(1 nm)/Si ) after annealing of Cu/barrier/Si and the results are consistent with XRD results. For the Cu/Zr(20 nm)/Si structure, the maximum stable temperatures in resistance improve 10□C after pre-annealing of barrier for 1 min at different temperatures. Thus, pre-annealing of barrier before sputter–depositing top Cu has no significant effect on the thermal stability of Cu/barrier/Si. With the XRD and FIB results showing the presence of copper silicides, the increases in resistance in Cu/barrier/Si are not observed. In the adhesion improvement study, the adhesion of Cu film on barrierless Si was enhanced significantly by introducing minor amounts of O2 into Cu films.