A capacitance ratio method used for L-eff extraction of an advanced metal-oxide-semiconductor device with halo implant

The effective channel length of a metal-oxide-semiconductor (MOS) transisto r is usually extracted using current-voltage (I-V) methods. In a current MO S transistor, local surface channel mobility degradation due to halo implan ts used for obtaining better short channel performance in deep-quarter micr on devices degrades the extraction accuracy of the value of effective chann el length (L-eff). This paper describes an experimental wafer split under v arying halo implant conditions implemented to determine the accuracy of the L-eff values extracted using various methods based on the advanced 0.15 mu m complementary metal-oxide-semiconductor (CMOS) technology. The integrated systems engineering technology computer-aided design (ISE TCAD) two-dimens ional (2D) simulation tool and a modified capacitance-voltage (C-V) method were adopted to help determine the metallurgical channel-length L-met for e ach transistor under various halo implant conditions. The relationships bet ween L-met and L-eff values extracted using various methods (including I-V and C-V methods) were also compared. In using the proposed modified C-V met hod [capacitance-ratio (C-R) method], more consistent and reasonable L-eff data can be obtained even when a heavy halo implant dose is used.