Study of diffusion barrier and adhesion of electroless-deposited copper film on silanized silicon

• Main Authors: Ping-Heng Wu, 吳炳亨
• Other Authors: Chih-Ming Chen
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/3ks82c

碩士 === 國立中興大學 === 化學工程學系所 === 107 === As the performance requirements of electronic devices increase, it causes the wire density increases. Thus, the thickness of diffusion barrier reduces in response to an increase of wire density. However, when the thickness of diffusion barrier decreases to nanometer size, the diffusion barrier prepared by the traditional sputter process is unable to maintain its integrity. Therefore, finding a new replacement material is an urgent task in high wire density generation. It is worth noting that few papers research about the mechanism of diffusion barrier of organosilane compound. Furthermore, the orientation of organosilane compound grafted on Si surface is also a significant issue for the adhesion of Cu layer prepared by the electroless plating process. In this study, the all-wet copper metallization technique was carried out through silanization engineering using organosilane and PVP-nPd catalyst. According to the sheet resistance, XRD and SEM results, traditional diffusion barrier such as Cr and Ta/TaN fail at an annealing temperature of 500 and 600 oC, respectively, and the PVP-nPd/ETAS diffusion barrier fails at an annealing temperature of 700 oC. Therefore, PVP-nPd/ETAS diffusion barrier shows the best diffusion barrier capability. For TGA analysis, the thermal degradation of PVP starts at 400 oC and ends at 700 oC. Therefore, the diffusion barrier capability can separate into two parts to discuss. The ring steric obstacle of pyrrolidone on PVP contributes to the diffusion barrier capability below 400 oC. The ETAS/PVP-nPd diffusion barrier still shows good diffusion barrier capability above 400 oC. For the adhesion of electroless deposition of Cu, the Cu layer deposited on EP55 co-silanized silicon shows the highest adhesion. According to ARXPS analysis, there are more –NH2 groups expose on Si surface and form coordination covalent bond with Cu atoms. That’s the reason why the adhesion of Cu deposited on EP55 co-silanized Si is higher than that of Cu deposited on ETAS silanized Si.