Deep X-ray lithography (DXRL), a fabrication method for the production of microstructures with a high aspect ratio, plays an important role in the subsequent electroplanting process. However, secondary radiation is generated during X-ray exposure and damages the resist adhesion to the metal layer. To solve adhesion problems, we modified the conventional DXRL process, changing the sequence of polymer adhesion in DXRL process. With optimized X-ray exposure and development conditions based on a calculated and modified X-ray power spectrum, we fabricated various polymer microstructures and achieved a maximum aspect ratio of 40.