The Impact of TEM Analysis Temperature on Photoresist Profiles Using Cryo-FIB and Cryo-TEM

Abstract Photoresist (PR) profiles tend to have deformation and shrinkage with typical transmission electron microscopy (TEM) analysis method using a focused ion beam scanning electron microscope (FIB-SEM) and TEM. The elevated temperatures during sample preparation and TEM analysis are believed to contribute to these issues. This study evaluates the effectiveness of cryogenic workflow in mitigating PR profile shrinkage by employing cryo-focused ion beam (Cryo-FIB) and cryo-transmission electron microscopy (Cryo-TEM). Comparative experiments were conducted at room temperature and cryogenic conditions, demonstrating that full cryogenic workflow reduces the shrinkage of PR, bottom anti-reflective coating (BARC), and line critical dimension (CD). Our findings indicate that both the sample preparation and analysis temperatures influence PR profiles. This study highlights how the full cryogenic workflow significantly minimizes shrinkage, providing more accurate PR profile measurements.