Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4971050 | Microelectronic Engineering | 2017 | 5 Pages |
3D sequential integration, such as CoolCubeâ¢, allows to stack vertically layer of devices. Levels of interconnection, also called intermediate Back-End-Of-Line, are needed between successive layers of transistors to avoid routing congestion. Thus, thermal stability of the dielectrics must be studied in order to fulfil the CoolCube⢠requirement: at least to be stable up to 500 °C during 2 h. Consequently, the stability of several barrier layers and oxide based materials has been studied through optical characterizations (ellipsometry, Fourier Transform InfraRed spectroscopy and ellipsometric-porosimetry). SiCO (k = 4.5), in replacement of standard SiCNH (k = 5.6) material as barrier layer seems very promising. Regarding the inter-layer dielectric stability, the state-of-the-art porous SiOCH (k = 2.5) stays suitable for a thermal budget of 500 °C, 2 h.
Graphical abstractDownload high-res image (101KB)Download full-size image