Midterm Exam Solutions for EECS 105 - Microelectronic Devices and Circuits, Spring 2001, Exams of Microeconomics

Download Midterm Exam Solutions for EECS 105 - Microelectronic Devices and Circuits, Spring 2001 and more Exams Microeconomics in PDF only on Docsity! First Midterm Exam, February 23, 2001 (53 Minutes) Use the following parameters for MOS devices. Here are a few fundamental constants and room temperature values. Problem Possible Score I 20 II 30 III 20 IV 30 Total 100 EECS 105 – Microelectronic Devices and Circuits Spring 2001, Prof. A. R. Neureuther Dept. EECS, 510 Cory 642-4590 UC Berkeley Office Hours M11, (Tu2), W2, Th2, F11 Course Web Site http://www-inst.EECS.Berkeley.EDU/~ee105/ Print Your Name:_____Solutions (see the following pages) Sign Your Name:________________________ ( )[ ]( ) DSDSnDSTnGSOXpn p Dn VVVVVCL W I λµ +−−     = 12/ ( ) ( )DSnTnGSOXnn n Dn VVVCL W I λµ +−    = 1 2 1 2 ( )[ ]( ) SDSDpSDTpSGOXpp p Dp VVVVVCL W I λµ +−+     =− 12/ ( ) ( )SDpTpSGOXpp p pD VVVCL W I λµ ++     =− 1 2 1 2 cmFxo /1085.8 14−=ε 9.3, =oxrε 7.11, =sirε KJxK /1038.1 23−= NMOS PMOS ì nCox=50ì A/V 2 ì pCox=25ì A/V 2 VT0n=1.0V VT0p=-1.0V γn=0.6V1/2 γp=0.6V1/2 ën=(0.1/L)V -1 L in ì m ëp=(0.1/L)V -1 L in ì m φp=-0.42 φn=0.42 202 102xni =eVVth 026.0= cm2/V-s 350 400 500 µp cm2/V-s 750 1200 1400 µn units 1017 1016 1015 mobility Cxq 19106.1 −= Assume L = 2 µm I. (20 Points) Threshold Voltage An NMOS process produces a device with a threshold voltage VTn = 1V and φp = - 0.42. Complete the table below that describes the percentage change in the electrical properties listed that is produced by the change shown in the columns for the oxide thickness and doping. You must briefly explain your listed percentages with footnotes 1-6 as indicated. Electrical Parameter Oxide thickness tOX Substrate doping Na doubles doubles 2φp 1 0% 4 +4.3% COX 2 -50% 5 0% QB,MAX/ COX 3 +100% 6 +44% 1) No effect 2) COX is inverse with tOX 3) COX decreases causes inverse Q/ COX increase 4) (2) 26mV ln(2) = 36mV or 4.3% of 840 mv 5) No effect 6) Sqrt((2 * (1.043)) = 1.44 or 44% EE 105 Sp 2001 A. R. Neureuther Solutions First Midterm Exam, February 23, 2001 (53 Minutes) Version 2/25/01