Optical lithography : here is why /
This book is aimed at new and experienced engineers, technology managers, and senior technicians who want to enrich their understanding of the image formation physics of a lithographic system. Readers will gain knowledge of the basic equations and constants that drive optical lithography, learn the...
Clasificación: | Libro Electrónico |
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Autor principal: | |
Autor Corporativo: | |
Formato: | Electrónico eBook |
Idioma: | Inglés |
Publicado: |
Bellingham, Wash. :
SPIE,
2010.
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Colección: | SPIE monograph ;
PM190. |
Temas: | |
Acceso en línea: | Texto completo |
Tabla de Contenidos:
- Preface
- Chapter 1. Introducing optical lithography. 1.1. The role of lithography in integrated circuit fabrication
- 1.2. The goal of lithography
- 1.3. The metrics of lithography
- 1.4. The contents of this book.
- Chapter 2 Exposure systems. 2.1. Proximity printing
- 2.2. Projection printing and a comparison to proximity printing
- 2.3. Full-wafer field
- 2.4. Step and repeat
- 2.5. Step and scan
- 2.6. Reduction and 1X systems
- 2.7. 1X mask fabricated with a reduction system
- 2.8. Summary
- References.
- Chapter 3. Image formation. 3.1. The aerial image. 3.1.1. Effects of a spherical wavefront and deviations from it; 3.1.2. Spherical wavefront; 3.1.3. The effect of a finite numerical aperture on the spherical wavefront; 3.1.4. Deviation from a spherical wavefront; 3.1.5. Imaging from a mask pattern; 3.1.6. Spatial frequencies; 3.1.7. Imaging results
- 3.2. Reflected and refracted images. 3.2.1. Methods to evaluate the reflected and refracted image from a mask; 3.2.2. Impact of multiple reflections on DOF
- 3.3. The latent image
- 3.4. The resist image. 3.4.1. The A, B, C coefficients; 3.4.2. The lumped parameters; 3.4.3. [Beta] and [eta]
- 3.5. From aerial image to resist image
- 3.6. The transferred image. 3.6.1. Isotropic etching; 3.6.2. Anisotropic etching; 3.6.3. Lift off; 3.6.4. Ion implantation; 3.6.5. Electroplating
- References.
- Chapter 4. The metrics of lithography. 4.1. The resolution and DOF scaling equations
- 4.2. Determination of k1 and k3 based on microscopy
- 4.3. Determination of k1, k2, and k3 based on lithography. 4.3.1. E-D branches, trees, and regions; 4.3.2. E-D window, DOF, and exposure latitude; 4.3.3. Determination of k1, k2, and k3 using E-D windows
- 4.4. k1, k2, and k3 as normalized lateral and longitudinal units of dimension
- 4.5. The E-D tools. 4.5.1. Construction of E-D trees; 4.5.2. Importance of log scale in the exposure axis; 4.5.3. Elliptical E-D window; 4.5.4. EL-versus-DOF tradeoff; 4.5.5. Incorrect elliptical E-D window; 4.5.6. CD-centered versus full-CD-range E-D windows; 4.5.7. E-D window and CD control; 4.5.8. Application of E-D tools
- References.
- Chapter 5. Components in optical lithography. 5.1. Light source. 5.1.1. Mercury arc lamp; 5.1.2. Excimer laser
- 5.2. Illuminator. 5.2.1. Köhler illumination system; 5.2.2. Off-axis illumination
- 5.3. Masks. 5.3.1. Mask substrate and absorber; 5.3.2. Pellicles; 5.3.3. Critical parameters for masks; 5.3.4. Phase-shifting masks
- 5.4. Imaging lens. 5.4.1. Typical lens parameters; 5.4.2. Lens configurations; 5.4.3. Lens aberrations; 5.4.4. Lens fabrication
- 5.5. Lens maintenance
- 5.6. Photoresists. 5.6.1. Classifications; 5.6.2. Light interactions with a photoresist; 5.6.3. Profile of resist images
- 5.7. Antireflection coatings
- 5.8. Wafer
- 5.9. Wafer stage
- 5.10. Alignment system. 5.10.1. Off-axis alignment and through-the-lens alignment; 5.10.2. Field-by-field, global, and enhanced global alignment; 5.10.3. Bright-field and dark-field alignments
- References.
- Chapter 6. Processing and optimization. 6.1. Optimization of the exposure tool. 6.1.1. Optimization of NA; 6.1.2. Optimization of illumination; 6.1.3. Exposure and focus; 6.1.4. DOF budget; 6.1.5. Exposure tool throughput management
- 6.2. Resist processing. 6.2.1. Resist coating; 6.2.2. Resist baking; 6.2.3. Resist developing; 6.2.4. Aspect ratio of resist image; 6.2.5. Environmental contamination
- 6.3. k1 Reduction. 6.3.1. Phase-shifting masks; 6.3.2. Off-axis illumination; 6.3.3. Scattering bars; 6.3.4. Optical proximity correction
- 6.4. CD uniformity. 6.4.1. CDNU analysis; 6.4.2. CDU improvement
- References.
- Chapter 7. Immersion lithography. 7.1. Introduction
- 7.2. Resolution and DOF. 7.2.1. Wavelength reduction and spatial frequencies; 7.2.2. Resolution and DOF scaling equations; 7.2.3. Improving resolution and DOF with an immersion system
- 7.3. DOF in multilayered media. 7.3.1. Transmission and reflection in multilayered media; 7.3.2. Effects of wafer defocus movements; 7.3.3. Diffraction DOF; 7.3.4. Required DOF; 7.3.5. Available DOF; 7.3.6. Preferred refractive index in the coupling medium; 7.3.7. Tradeoff between resolution and DOFdiffrac
- 7.4. Polarization-dependent stray light. 7.4.1. Imaging at different polarizations; 7.4.2. Stray light
- 7.5. Immersion systems and components. 7.5.1. Configuration of an immersion system; 7.5.2. The immersion medium; 7.5.3. The immersion lens; 7.5.4. Bubbles in the immersion medium; 7.5.5. The mask; 7.5.6. Subwavelength 3D masks; 7.5.7. The photoresist
- 7.6. Impact on technology. 7.6.1. Simulation for an immersion system; 7.6.2. Polylayer; 7.6.3. Contact layer; 7.6.4. Metal layer; 7.6.5. Recommendation for the three technology nodes
- 7.7. Practicing immersion lithography. 7.7.1. Printing results; 7.7.2. Defect reduction; 7.7.3. Monitoring the immersion hood and special routing; 7.7.4. Other defect-reduction schemes; 7.7.5. Results
- 7.8. Extension of immersion lithography. 7.8.1. High-index materials; 7.8.2. Solid-immersion mask; 7.8.3. Polarized illumination; 7.8.4. Double exposures and pitch splitting; 7.8.5. Pack-unpack; 7.8.6. Overcoming the throughput penalty with double imaging
- 7.9. Conclusion on immersion lithography
- References.
- Chapter 8. Outlook and successors to optical lithography. 8.1. Outlook of optical lithography. 8.1.1. Optical lithography galaxy for logic gates; 8.1.2. Optical lithography galaxy for contact holes; 8.1.3. Optical lithography galaxy for equal lines and spaces
- 8.2. EUV lithography. 8.2.1. Introduction; 8.2.2. EUV sources; 8.2.3. EUV masks; 8.2.4. EUV projection optics; 8.2.5. Wall-power consumption; 8.2.6. EUV resist; 8.2.7. EUV OPC; 8.2.8. Summary of EUVL
- 8.3. Massively parallel E-beam maskless imaging. 8.3.1. Introduction to e-beam imaging; 8.3.2. MEB ML2 systems proposed; 8.3.3. Comparison of the different systems; 8.3.4. Data volume and the rate of DW systems; 8.3.5. Power consumption of MEB ML2; 8.3.6. Extendibility of MEB ML2 systems; 8.3.7. Comparison of 4X mask writing to 1X wafer writing; 8.3.8. Applications for MEB ML2; 8.3.9. Summary of MEB ML2
- 8.4. Outlook of lithography. 8.4.1. Double patterning; 8.4.2. EUV lithography; 8.4.3. MEB ML2; 8.4.4. Nanoimprint lithography
- 8.5. Conclusions
- References
- Index.