Recitation  MOSFET VI Characteristics II

Recitation MOSFET VI Characteristics II - Description

012 Spring 2009 Recitation 10 MOSFET VI Characteristics Channel Length Modulation Back Gate E64256ect Yesterday we discussed two more aspects in MOSFET IV characteristics Channel length modulation Backgate e64256ect Here is the nMOS IV characteris ID: 23982 Download Pdf

85K - views

Recitation MOSFET VI Characteristics II

012 Spring 2009 Recitation 10 MOSFET VI Characteristics Channel Length Modulation Back Gate E64256ect Yesterday we discussed two more aspects in MOSFET IV characteristics Channel length modulation Backgate e64256ect Here is the nMOS IV characteris

Similar presentations


Download Pdf

Recitation MOSFET VI Characteristics II




Download Pdf - The PPT/PDF document "Recitation MOSFET VI Characteristics II" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.



Presentation on theme: "Recitation MOSFET VI Characteristics II"— Presentation transcript:


Page 1
Recitation 10 MOSFET VI Characteristics II 6.012 Spring 2009 Recitation 10: MOSFET VI Characteristics - Channel Length Modulation & Back Gate Effect Yesterday we discussed two more aspects in MOSFET IV characteristics. Channel length modulation Backgate effect Here is the n-MOS IV characteristic (ideal, no channel length modulation) What about the IV characteristic for a p-MOS?
Page 2
Recitation 10 MOSFET VI Characteristics II 6.012 Spring 2009 Channel Length Modulation NMOS What happens when DS GS ox GS DS )=0 DS ox GS DS PMOS When SD SG ox SG SD )=0


Page 3
Recitation 10 MOSFET VI Characteristics II 6.012 Spring 2009 As a result, To model it, we have: ox GS (1 + λV DS (or ox SG (1 + λV SD )) e.g. The ideal case is the ideal current source, now we have a current source with some internal resistance (will talk about this later). Note: pinch-off region does not impede current flow near drain (high lateral E-field near drain makes them go fast)
Page 4
Recitation 10 MOSFET VI Characteristics II 6.012 Spring 2009 Backgate Effect NMOS When BS =0, FB +2 qN ox FB gate body )) When BS 0, BS )= FB

+2 qN BS ox Backgate effect parameter: =2 qN ox BS )= TO BS PMOS When BS =0, FB qN (+2 ox FB gate body )) When SB 0, or BS SB )= FB qN (2 SB ox =2 qN ox SB )= (2 SB
Page 5
Recitation 10 MOSFET VI Characteristics II 6.012 Spring 2009 Exercise NMOS, channel doping =10 17 cm GS vary from 0 5V BS =0 5V. = 10 V when BS =0; = 2 V when BS 5 V. What is ? What is ox =2 qN to find , need to know ox ox BS )= BS 42 V 2V = 1V+ 84 V + 0 5V 84 V) = =0 67V ox =2 qN times 10 12 cm 10 19 10 17 cm 67 V =2 10 cm When GS =3V DS =0 1V BS = 0 V, what is the channel electron charge density at


Page 6
Recitation 10 MOSFET VI Characteristics II 6.012 Spring 2009 the drain? ox GS DS )=2 10 cm (3 1) V = When DS =0 1V GS =3V BS 5 V, what is the channel electron charge density at the drain? ox GS BS DS )=
Page 7
IT OpenCourseWare http://ocw.mit.edu 6.012 Microelectronic Devices and Circuits Spring 2009 For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms .