We evaluated three spin-on carbon hardmasks from Irresistible Materials [12]. The spin-on carbon compositions were dissolved in a suitable solvent such as chloroform or anisole with a concentration in the range 5–50g/l. In this report, film thickness measurements were made for IM-HM11-01 and IM-HM11-02 films, whilst IM-HM11-03 was used for etching; further investigations to compare the performance of the different compositions across tasks are underway. Films of the SoC were prepared by spin coating on hydrogen-terminated silicon substrates with a speed varying between 800 and 2000 RPM for 60s. After spin coating the film was baked for 2min at temperatures of up to 330°C. In order to enable further processing, the SoC should be rendered insoluble in typical solvents for resist and spin-on-hardmask to enable further processing. The elution behavior of films of IM-HM11-01 and IM-HM11-02 for thicknesses between 30 and 325nm was tested as a function of the baking temperature. Fig. 1 shows the normalized film thickness of two formulations of the SoC (IM-HM11-01 and IM-HM11-02), before and after dipping in monochlorobenzene (MCB):IPA 1:1 solution. Prior to baking the thickness of IM-HM11-01 was ∼320nm, and the thickness of IM-HM11-02 was ∼250nm. For temperatures above 190°C the IM-HM11-02 film was rendered insoluble, whilst a temperature of 260°C was required to achieve the same for IM-HM11-01. Film thickness did not affect the elution results.
