POLYMER HAVING AROMATIC RING AND UNDER-LAYER COMPOSITION OF RESIST INCLUDING THE SAME

摘要

PURPOSE: An aromatic ring-containing polymer is provided to ensure excellent thermal stability and etching resistance and to form a film as a protective film during a dry etching process. CONSTITUTION: An aromatic ring-containing polymer contains a repetitive unit of chemical formula 1. In chemical formula 1: R1 is a C5-20 monocyclic or polycyclic aromatic hydrocarbon; R2 and R3 are C4-14 monocyclic or polycyclic aromatic hydrocarbon; a is 1-3 of integer; and b is 0-2 of integer. The average molecular weight of the aromatic ring-containing polymer is 500-50,000. A resist underlayer composition contains the aromatic ring-containing polymer and an organic solvent.