Chemical Treatment of Low-k Dielectric Surfaces for Patterning of Thin Solid Films in Microelectronic Applications

• DOI: 10.1021/acsami.6b00495
• Publication Date: 2016-03-01T12:23:31Z
• Authors: Lei Guo; Xiangdong Qin; Francisco Zaera
• Keywords: Silanol; Octadecyltrichlorosilane; Microelectronics; Ellipsometry; Chemical Mechanical Planarization; Surface Modification

A protocol has been developed to selectively process low-k SiCOH dielectric substrates in order activate or deactivate them toward the deposition of thin solid films by chemical (CVD ALD) means. The original surfaces are hydrophobic, an indication that they alkyl- rather than silanol-terminated and that, consequently, fairly unreactive. However, chemical-mechanical polishing (CMP) sometimes done during microelectronics fabrication renders hydrophilic reactive. It was shown here silylation CMP-treated with any a number well-known agents such as HMDS, ODTS, OTS caps reactive silanol surface groups turns back being Further exposure passivated combination ozone UV radiation reinstates their hydrophilicity activity. Importantly, it also demonstrated all these changes could be induced without altering mechanical, optical, electrical properties samples: atomic force microscopy (AFM) images show no increase roughness, ellipsometry measurements yield same values for index refraction constant, infrared absorption spectroscopy attests preservation organic fragments present samples. selectivity resulting tested layer (ALD) HfO2 films, which grown only on UV/O3 treated substrates.