Mobility enhancement by CESL strain in short-channel ultrathin SOI MOSFETs

Deep-amorphization and solid-phase epitaxial regrowth processes for hybrid orientation technologies in SOI MOSFETs with thin body

“…Therefore, it can be concluded that the DA/SPER processes do not significantly damage the interfaces of the SOI film. Remark that S 1 is close to the ideal limit (65 mV/decade) even in short devices confirming similar results reported in [14]. Indeed, the large value of C ox1 masks any reasonable variation in D it1 (6 10 12 cm À2 e V À1 ) due to the presence of defects.…”

Mechanics of silicon nitride thin-film stressors on a transistor-like geometry

“…Another widely adopted concept is based in the deposition of a stressed film, typically Silicon Nitride (SiN) (also referred to as capping etch stopping layers (CESL)), over the transistor structure. [13][14][15][16][17] In this case, the strain in the channel results from mechanical interactions which depend on the geometry of the system and characteristics of the films. In contrast to Si x Ge 1-x and Si x C 1-x , for which the elastic behavior is well understood, our knowledge is limited on how amorphous SiN thin films behave in terms of developing stresses and mechanical properties, 18 particularly when featured over nanoscopic geometries of an intricate nature.…”

Characterization of the electrical properties of advanced silicon-on-insulator (SOI) materials and transistors

“…Figure 2.6a shows a gain in hole mobility of 80% induced by the contact etch stop layer (CESL) in 100 nm long p-channel MOSFETs. 25 The mobility dependence on channel length indicates the localization of strain at the channel extremities, as confi rmed by mechanical simulations. 37 In a long MOSFET, there is no mobility gain because most of the channel remains unstressed.…”

“…As usual, low-temperature measurements are very helpful in providing details and identifying the physical mechanism: carrier scattering by remote Coulomb centers, located in the high-K stack. 25 Effective channel length and width are normally evaluated by comparing devices with variable geometry. Several issues have to be considered: Effective length can be slightly different at front and back channels.…”