{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

VLSI_Class_Exam_I_2007

# VLSI_Class_Exam_I_2007 - EEL 5322 VLSI Circuits and...

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

EEL 5322 VLSI Circuits and Technology Exam I, 2007 Open Note, Open Book, 60 Minutes, 100 points PROBLEM 1: (50 Points) NAME: . Oxidation, Statistics UFID: . A 0.2 μ m (200 nm) Si Nitride layer is patterned over the Silicon substrate and used as an etch mask to build a 550nm deep, 5000nm wide trench. A 50 nm layer of dry Oxide was grown on the surface of the trench. Assume the standard oxidation equations and rate constants work for the structure shown below. Silicon substrate (500um thick) Silicon (350nm thick) Si Nitride (200nm thick) Silicon (350nm thick) Si Nitride (200nm thick) LTO 50 nm Trench For Silicon Oxidation <111>, 1 1 E kT B C e = and 2 2 E kT B C e A = Dry O 2: C 1 = 7.72 x10 2 um 2 /hr E 1 =1.23 eV C 2 = 3.71 x10 6 um 2 /hr E 2 =2.00 eV H 2 O (640 torr): C 1 = 3.86x10 2 um 2 /hr E 1 =0.78eV C 2 = 0.97x10 8 um 2 /hr E 2 =2.05eV a) Find how long it takes to grow an additional 0.5 μm (500 m) of wet oxide on top of the 50 m of dry oxide, (550 m of oxide total thickness on the silicon at the center of the trench) at 1000 o C? Hint, check the in class oxidation handout for 1000 o C oxidation rate constants. (20 pts)

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

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

{[ snackBarMessage ]}