The Simulation Studies of Fabrication for 45 nm Contact Hole by Using Attenuated-Rim-Outrigger Phase Shifting Mask and Increasing Depth of Focus for 28 nm Line by Using Scattering Bar
|關鍵字:||減光-緣邊-外架型相移圖罩;45奈米接觸孔;28奈米線;散條;焦深;Attenuated-Rim-Outrigger Phase Shifting Mask;45 nm Contact Hole;28 nm Line;Scattering Bar;Depth of Focus|
|摘要:||本論文使用美國KLA-Tencor之光學微影模擬軟體ProLith v. 9.0，主要探討以減光-緣邊-外架型相移圖罩製備45奈米接觸孔與以散條提升28奈米線焦深。重要發現如下：
The lithographic simulation software of Prolith v. 9.0 from USA KLA-Tencor was used in this thesis. The main studies are fabrication for 45 nm contact hole by using attenuated-rim-outrigger phase shifting mask and increasing depth of focus (DOF) for 28 nm line by using scattering bar. Some important findings are reported as following: 1. The fabrication studies for 2-dimension 45 nm contact hole, using firstly reported attenuated-rim-outrigger phase shifting mask by this thesis, and combined with annular off-axis illumination, DOF was found to be the best, mask error enhancement factor can also be maintained nearly in 1. The shortcoming of this combination was very high exposure dose, easy to cause excessively strong sidelobe intensity, and therefore developed. 2. The fabrication for 1-dimension 28 nm line, the positive bias method combined with rim attenuated scattering bar (R-ASB) and center attenuated scattering bar (C-ASB), DOF increasing effect was found the be the best, forbidden pitches can be improved. The two methods which are positive bias and the adding of side attenuated scattering bar (S-ASB) have shown to have approximate effect to the DOF increase. By observation of aerial image from space, C-ASB can be added only when the interference waves formed by edge effect began to separate. If the interference waves have not yet separated, the adding of C-ASB will affect the aerial images of main lines instead, and DOF will be decreased. 3. The fabrication of isolated lines will not be hampered by the general formula of half pitch resolution (R=K1λ/sinβ). When NA was set as 1.35, 22 nm and 16 nm isolated lines can be fabricated by positive bias. If the Dupont second generation immersion liquid (refractive index n=1.64) is used, transmittance of main lines of attenuated phase shift mask raised, and NA enlarged to 1.50, 12 nm and 8 nm isolated lines can be fabricated.