S2011_221B_HW3

S2011_221B_HW3 - ECE 221B - Home Work 3 - 2011 2010 ECE...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
ECE 221B Spring 2010 Homework 2 Due: Thursday May 13, 2010 I. Polar HEMT a. 8.19 b. 8.20 2. Consider the Ga-face GaN/AlN/GaN HEMT structure shown in Figure 5-1 (2DEG not shown), with a donor delta-doping of N D cm -2 inserted d 1 /3 from the top GaN/AlN interface. All layers are fully strained to the GaN buffer. You may find the following information useful: E g (GaN) = 3.4 eV, E g (AlN) = 6.2 eV; Net polarization charge at AlN/GaN interface with AlN strained to GaN is 6.8x10 13 cm -2 ; E C at AlN/GaN interface = 1.8 eV; Assume the centroid of the 2DEG overlaps with the polarization charges at the 2DEG interface; Surface pinning on undoped GaN = 1 eV; ε r =10 for all materials. (a) Derive the expression of n s in terms of N D , the intrinsic material properties (band-offsets, polarization charges, etc) and the layer thicknesses (d 1 , d 2 ). Assume that the donors are fully depleted. (b) Calculate the charges and the band diagram of the structure in (a). The
Background image of page 1

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

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 2

S2011_221B_HW3 - ECE 221B - Home Work 3 - 2011 2010 ECE...

This preview shows document pages 1 - 2. Sign up to view the full document.

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