1 / 12

Tunneling Devices

Tunneling Devices. Motivation. Scaling : some proposed tunneling field effect transistor (TFET) designs do not suffer from short channel effects Power Dissipation: TFETs can beat the 60 mV/decade sub-threshold swing of MOSFETs Design Flexibility: Circuits can be made with fewer devices.

seda
Download Presentation

Tunneling Devices

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Tunneling Devices

  2. Motivation • Scaling: some proposed tunneling field effect transistor (TFET) designs do not suffer from short channel effects • Power Dissipation: TFETs can beat the 60 mV/decade sub-threshold swing of MOSFETs • Design Flexibility: Circuits can be made with fewer devices

  3. human brain in 2012? Obligatory Moore’s Law Reference http://www.intel.com/research/silicon/mooreslaw.htm

  4. What’s so great about a tunneling device? • Lower sub-threshold swing can allow for lower operating voltages to be used • Negative differential resistance (NDR) properties can be exploited to create simpler designs for bi-stable circuits, differential comparators, oscillators, etc. • Leads to chips that consume less power

  5. Tunneling • Tunneling is a quantum mechanical phenomenon with no analog in classical physics • Occurs when an electron passes through a potential barrier without having enough energy to do so

  6. (Esaki) Tunnel Diode (TD) EC EV EF • Simplest tunneling device • Heavily-doped pn junction • Leads to overlap of conduction and valence bands • Carriers are able to tunnel inter-band • Tunneling goes exponentially with tunneling distance • Requires junction to be abrupt

  7. Band-to-Band Tunneling in a Tunnel Diode (c) (e) I (b) (d) V EC (a) EV EF (a) (b) (c) (d) (e)

  8. I V Figures of Merit Peak current 100 kA/cm2 Peak-to-Valley Ratio (PVR)

  9. Bi-stable Configuration V I D1 X D2 X1 X2 V

  10. TD Differential Comparator VCC D3 D4 CK X M3 M4 D1 D2 VOUT VOUT VIN VIN RL RL M1 M2 I1 I2 ITAIL -VEE

  11. Direct vs. Indirect Tunneling Indirect Direct Indirect materials require phonons to tunnel, thus reducing the probability of a tunneling event

  12. Tunnel Current Expressions

More Related