Friday, April 12, 2013
TSMC Proposes Way to Reduce RTS Noise
TSMC patent application US20130082312 "Transistors, Methods of Manufacturing Thereof, and Image Sensor Circuits with Reduced RTS Noise" by Feng-Chi Hung, Jhy-Jyi Sze, and Shou-Gwo Wuu proposes an approach to reduce RTS noise in SF transistors. The proposal is to add Vth adjust implants 146 on the edges of STI 138 to push the inversion channel toward the middle of MOSFET gate 154:
This structure looks like that used by some radiation harden designs. Are there any results on the RTS performance measurement on the raidation hardened MOS transistors from this community ? Normaly they look only on the leakage current ...
ReplyDelete-yang ni
Hi Yang. P
Deleteeople working on particle detectors reported radiation effects on RTS noise of source followers in 90 nm and 130 nm CMOS. They saw an increase of RTS noise and attributed it to an increase of positive charges in the STI trench next to the channel. The current would flow more at the side of the channel where there is a higher density of charge traps causing RTS. I can not find back the paper now but the presenter was Valerio Re of the univ. of Bergamo.
Then countermeasures are then indeed similar to TSMC's, or the use of enclosed gate transistors.
Thanks Guy for this information !
Delete-yang ni
http://www.ee.nthu.edu.tw/shhsu/journal%20papers/Impact%20of%20STI%20of%20flicker%20noise.pdf
ReplyDelete-yang ni
Thanks Yang, interesting article.
ReplyDeleteI found back the paper meanwhile where I wrote about:
V. Re et al, "Review of radiation effects leading to noise performance degradation in 100-nm scale microelectronic technologies", 2008 IEEE Nuclear Science Symposium Conference Record, N49-1, page 3086-3090
They show 1/f noise spectra before and after 10 Mrad total dose, in 130 nm and 90 nm technologies.