Characterization of a positive-tone wet silylation process with the AZ 5214 photoresist

Abstract A liquid-phase (wet) silylation process has been developed using the commercial photoresist AZ 5214 ™ , and I-line lithography. The resist is dry developed with O 2 reactive ion etching (RIE); a subsequent CHF 3 /SF 6 RIE, transfers on oxide lines finer than the theoretical resolution limit of the lithographic step. Proton nuclear magnetic resonance (NMR) spectroscopy, Rutherford backscattering spectroscopy (RBS), and scanning electron microscopy (SEM) of submicron patterns are used to characterize the process. Their results are consistent with each other, provding Si densities ranging from 20 to 200 × 10 15 atoms/cm 2 , and Si depths of a few hundred nm. The silylation speed can be as high as 700 nm/min, and is reduced at increasing concentrations of the silylating agent, and at the finest patterns. We demonstrate here that NMR is an excellent method of qualitative and quantitative analysis of silylated films.