lecture28 - Lecture 28 Monday April 11 EE 332 Semiconductor...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon

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

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Lecture 28 Monday April 11 EE 332 Semiconductor Devices Problem Assignment Monday Æ Problems S3.4a Definitions φ f = separation of E i and E F φ s is total bend in the band at the oxide interface. φ s >0 Æ bend down, φ s = 0 Æ flat band. When φ s > φ f inversion exists. = = i A f s n N q kT ln 2 2 ) inv ( φ φ fs i f E E q − = φ For strong inversion Interface Charge Produces Band Bending. Define Flat Band Potential = V FB = Φ m- Φ s -Q i /C’ ox = Φ ms-Q i /C’ ox Interface Charge Sodium ions are common contaminants in SiO 2 and they are relatively mobile. 1. Let positive mobile Na + be Q m (problem solved) 2. Trapped charge in oxide = Q ot (problem solved) 3. Charge at interface states due to the termination of the Si crystal lattice be Q it 4. At Si-SiO 2 interface, let charges in SiO x be Q f Q it +Q f =10 10 /cm 2 on {100} surface and a factor of ten higher on {111} surface. Q ot and Q m are near zero for a good process. Let Q i =Q f +Q it =total interface charge In the Depletion Region () () [ ] w C...
View Full Document

{[ snackBarMessage ]}

Page1 / 4

lecture28 - Lecture 28 Monday April 11 EE 332 Semiconductor...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online