A study of SRAM NBTI by OTF measurement

Author

Aono, H. ; Murakami, E. ; Shiga, K. ; Fujita, F. ; Yamamoto, S. ; Ogasawara, M. ; Yamaguchi, Y. ; Yanagisawa, K. ; Kubota, K.

Author_Institution

Renesas Technol. Corp., Hitachinaka

fYear

2008

fDate

April 27 2008-May 1 2008

Firstpage

67

Lastpage

71

Abstract

A mechanism of DeltaVth variation of NBTI for SRAM load transistor is examined. The variation data is in good agreement with our proposed model. A large fluctuation of NBTI for small size pMOS is not observed in HCI measurement for nMOS, which may be due to the difference of recovery. Two types of equations to get DeltaVth from DeltaIdL by OTF measurement are compared and we have concluded which equation is appropriate by using pulse IV method. We have also proposed a new method to predict precise median value of NBTI for SRAM by OTF measurement with parallel TEG. This method is very important to design initial Vth region of SRAM.

Keywords

MOSFET; SRAM chips; NBTI; OTF; SRAM load recovery; fluctuation; negative bias temperature stability; pMOS transistor; Circuit testing; Equations; Fluctuations; MOS devices; MOSFETs; Niobium compounds; Pulse measurements; Random access memory; Stress; Titanium compounds; NBTI; OTF; SNM; SRAM;

fLanguage

English

Publisher

ieee

Conference_Titel

Reliability Physics Symposium, 2008. IRPS 2008. IEEE International

Conference_Location

Phoenix, AZ

Print_ISBN

978-1-4244-2049-0

Electronic_ISBN

978-1-4244-2050-6

Type

conf

DOI

10.1109/RELPHY.2008.4558865

Filename

4558865