Open AccessFabrication method for annular/shielded copper interconnects
Author(s) -
Adamshick Stephen,
Burke John,
Liehr Michael
Publication year - 2017
Publication title -
micro and nano letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.25
H-Index - 31
ISSN - 1750-0443
DOI - 10.1049/mnl.2016.0462
Subject(s) - copper interconnect , shielded cable , tantalum nitride , copper , materials science , diffusion barrier , trench , interconnection , optoelectronics , fabrication , microelectronics , nanotechnology , electrical engineering , metallurgy , tantalum , computer science , engineering , medicine , pathology , computer network , alternative medicine , layer (electronics)
This study outlines a method for fabricating annular/shielded on chip copper interconnects. Traditional damascene copper wires only require one diffusion barrier to prevent copper migration into dielectrics for trench style interconnects. However, for annular or shielded interconnects, an additional diffusion/oxidation barrier is required to protect the integrity of the copper especially on the trench sidewalls. Two methods are explored in this study to create the second barrier that includes materials such as tantalum nitride and silicon nitride (SiN). The experimental results are analysed using scanning electron microscopy (SEM) and high frequency electrical measurements to characterise the effectiveness of each respective technique. The results demonstrate the feasibility of creating annular/shielded copper interconnects using standard damascene processing techniques to maintain lower costs of process development. Furthermore, the results conclude the SiN based barrier effectively prevents oxidation of copper as verified with both SEM and electrical data. The development of this knowledge will aid in advancing back end interconnect technology to help solve the data bottleneck issue currently challenging the semiconductor industry.