lec06_-_cmos_fabrication_process - Copy

lec06_-_cmos_fabrication_process - Copy -...

Info icon This preview shows pages 1–9. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Microelectronics (Part 2) Chapter 5: CMOS Fabrication Technology
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Course Outcomes CO2: to identify the sequences of fabrication process in constructing the physical layout of CMOS circuit 2
Image of page 2
Review: Fabrication Process 3 Epitaxy, Deposition, Ion-Implantation and Diffusion Epitaxy : growing a single-crystal film on the silicon surface by injecting the silicon wafer surface to elevated temperature and a source of dopant material MOSFET gates Deposition : evaporating dopant material onto silicon surface followed by a thermal cycle, which is used to drive the impurities from the silicon into the bulk Interconnections *Sputtering SiO 2 Ion implantation : subjecting the silicon substrate to highly energized donor or acceptors atoms. When these atoms strike on the silicon surface, they travel below the surface of the silicon, forming regions with varying doping concentrations The patterned SiO2 serves as an implantation mask Source and Drain regions
Image of page 3

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Review: Fabrication Process 4 Epitaxy, Deposition, Ion-Implantation and Diffusion Diffusion : at an elevated temperature will occur between any silicon that has differing densities of impurities, with impurities tending to diffuse from areas of high concentration to areas of low concentration Well * Oxidation : forming silicon dioxide (SiO 2 )
Image of page 4
CMOS Basics CMOS Inverter Cross-section
Image of page 5

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Review: Lithography/Photolithography Photolithography is the standard process to transfer a pattern on to a certain material 1. Photoresist application The surface to be patterned is spin-coated with a light-sensitive material (photoresist) 2. Printing (exposure) The mask pattern is developed on the photoresist, with UV light exposure Depending on the type of photoresist (negative or positive), the exposed or unexposed parts become resistant to certain types of solvents 3. Development The soluble photoresist is chemically removed (etching process) The developed photoresist acts as a mask for patterning of underlying layers and then is removed
Image of page 6
Review: Fabrication of p-n Junction Process Description Cross-section Starting material: p-type wafer Mask 1: Pattern n+ region with photoresist Process: Ion-Implantation p-Si n + photoresist n-dopant implant (e.g. As + )
Image of page 7

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Review: Fabrication of p-n Junction Process Description Cross-section Mask 2: Pattern openings for Metal contacts Process: Oxidation + photolithography p-Si n + SiO 2 SiO 2 SiO 2
Image of page 8
Image of page 9
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern