Title :
Graded-junction gate/n- overlapped LDD MOSFET structures for high hot-carrier reliability
Author :
Okumura, Yoshinori ; Kunikiyo, Tatsuya ; Ogoh, Ikuo ; Genjo, Hideki ; Inuishi, Masahide ; Nagatomo, Masao ; Matsukawa, Takayuki
Author_Institution :
Mitsubishi Electr. Corp., Hyogo, Japan
fDate :
12/1/1991 12:00:00 AM
Abstract :
A newly developed gate/n- overlapped LDD MOSFET was investigated. The MOSFET was fabricated by an oblique rotating ion implantation technique. A formula for the impurity ion profile was derived to analyze the lowering of substrate current and improvement of the degradation caused by the hot-carrier effect of the MOSFET. It was proved that the impurity ion profile near the drain edge is remarkably graded in the directions along channel and toward substrate even just after the implantation, so that the maximum lateral electric field is relaxed as compared with conventional LDD MOSFETs. Also, the maximum point of the lateral electric field at the drain edge is located apart from the main path of the channel current
Keywords :
carrier density; doping profiles; hot carriers; insulated gate field effect transistors; ion implantation; reliability; semiconductor device testing; LDD MOSFET; carrier concentration; channel current; graded junction gate n- overlapped structure; high hot-carrier reliability; hot carrier degradation; impurity ion profile; maximum lateral electric field; oblique rotating ion implantation; substrate current; Cause effect analysis; Degradation; FETs; Helium; Hot carrier effects; Hot carriers; Impurities; Ion implantation; MOSFET circuits; Stress;
Journal_Title :
Electron Devices, IEEE Transactions on
