Fabrication and Simulation of MoSiO Embedded Material for Embedded Attenuated Phase-Shifting Mask
|關鍵字:||嵌附層;折射率;吸收係數;電子能譜化學分析儀與傅利葉轉換紅外光譜儀;傳統鉻膜圖罩搭配偏軸二孔發光;embedded layer;refractive index;absorptivity;ESCA and FT-IR;COG assisted with OAI dipole|
正規嵌附層MoSiO薄膜在濺鍍成膜時，改變通入氧氣流量，可得符合嵌附層之需求。此薄膜於微影波長193 nm之折射率為1.813，吸收係數為0.35，符合相移角度180度之薄膜厚度計算值為118.69 nm；另成膜方式為MoSi薄膜加以氧電漿改質，通入氧氣時間不同，光學性質亦不同，符合嵌附層之微影波長193 nm折射率為1.637，吸收係數為0.527，符合相移角度180度之薄膜厚度計算值為151.49 nm。
模擬結果顯示，以傳統鉻膜圖罩搭配偏軸二孔發光於248 nm微影時，可成功製作0.115 μm密集線隙，且對於焦深與製程寬容度具較佳之改善效果。|
Embedded Attenuated Phase-Shifting mask (EAPSM) is one of the important resolution enhancement techniques. The main point of this thesis is to study MoSiO which is material for EAPSM in 193 nm lithography, the effects of various ways of film growth on its optical and chemical properties. By changing the O2 flow rates in sputtering conditions, qualified MoSiO embedded layer could be obtained. Under 193 nm, refractive index of this film is 1.813, and absorptivity is 0.35, calculated thickness of this film which has a degree of phase shift 180 is 118.69 nm; in other different way of film preparation, MoSi film was treated with O2 plasma, the flow of oxygen also changed the property. For the qualified MoSiO film for 193 nm lithography, refractive index is 1.637, and absorptivity is 0.527, calculated thickness of this film which has a degree of phase shift 180 is 151.49 nm. The scattering light was generated from the surface of embedded layer which was not like a mirror, resulted in the facts that the measured reflectance and transmittance were smaller than its real reflectance and transmittance. The modified the R-T Method was used to determine n and k, and the values closed to the n and k measured by n＆k analyzer, so the value of modified method has been proved. Using ESCA and FT-IR to analyze MoSiO film, the increasing contents of SiO2 and MoO3 will increase n and decrease k. Therefore, the chemical compositions and optical properties are well correlated, however, their detailed correlations can not be verified. The result of simulation showed that traditional COG assisted with OAI dipole could fabricate 115 nm dense line in 248 nm, the DOF and process window were also improved.