Patent ID: 7410733

Claim:
A method of forming a EUV mask comprising: providing a substrate layer; forming a reflective multi-layer over said substrate layer; forming a buffer layer over said reflective multi-layer; forming a first EUV mask absorber over said buffer layer; forming a second EUV mask absorber over said first EUV mask absorber, wherein said second EUV mask absorber etches much more anisotropically as compared with said first EUV mask absorber, wherein said second EUV mask absorber etches relatively fast as compared with said first EUV mask absorber, and wherein said second EUV mask absorber layer is more than about two times as thick as said first EUV mask absorber layer; forming a trench through said second EUV mask absorber; deepening said trench through said first EUV mask absorber; deepening said trench through said buffer layer; and providing said reflective multi-layer with access to incident radiation directed through said trench, wherein opposing sidewalls of said deepened trench are substantially straight and parallel.