3.3.3 Vth Roll-Off, DIBL, and Subthreshold Slope Degradation

The DITS effect is taken into account through the parameter $\Theta_{DITS}$. The threshold voltage takes this effect into account through the parameter $\Delta V_{th,DIBL}$. In the equations shown below, $\Theta_{SW}$, $\Theta_{SS}$, $\Theta_{SCE}$, $\Theta_{DIBL}$ and $\Theta_{DITS}$ are model parameters in the code as $THETA\_SW$, $THETA\_SS$, $THETA\_SCE$, $THETA\_DIBL$ and $THETA\_DITS$, respectively.

$\psi_{st} = 0.4 + PHIN_i + \phi_B \qquad (3.245)$

$\Theta_{SW} = \dfrac{0.5}{cosh \Big( DVT1SS_i \cdot \dfrac{L_{eff}}{\lambda} \Big) - 1} \qquad (3.246)$

$C_{dsc} = \Theta_{SW} \cdot (CDSC[N] + CDSCD_a \cdot V_{dsx}) \qquad (3.247)$

$n = \begin{cases} \Theta_{SS} \cdot \Bigg( 1 + \dfrac{CIT_i + C_{dsc}}{(2 C_{si}) // C_{ox}} \Bigg) &\text{if } GEOMOD \ne 3 \\ \Theta_{SS} \cdot \Bigg( 1 + \dfrac{CIT_i + C_{dsc}}{C_{ox}} \Bigg) &\text{if } GEOMOD = 3 \end{cases} \qquad (3.248)$

$\Theta_{SCE} = - \dfrac{0.5}{cosh \Big( DVT1_i \cdot \dfrac{L_{eff}}{\lambda} \Big) - 1} \qquad (3.249)$

$\Delta V_{th,SCE} = \Theta_{SCE} \cdot DVT0_i \cdot (V_{bi} - \psi_{st}) \qquad (3.250)$

$\Theta_{DIBL} = - \dfrac{0.5}{cosh \Big( DSUB_i \cdot \dfrac{L_{eff}}{\lambda} \Big) - 1} \qquad (3.251)$

$\Theta_{DITS} = \dfrac{1.0}{ 1.0 + DVTP2 \cdot \Big[ cosh \Big( DSUB_i \cdot \dfrac{L_{eff}}{\lambda} \Big) - 2.0 \Big] }$

$(3.252)$

$\Delta V_{th,DIBL} = \Theta_{DIBL} \cdot ETA0_i \cdot V_{dsx} + \Theta_{DITS} \cdot DVTP0 \cdot {V_{dsx}}^{DVTP1} \qquad (3.253)$

$\Delta V_{th,RSCE} = K1RSCE_i \cdot \Bigg( \sqrt{1 + \dfrac{LPE0_i}{L_{eff}}} - 1 \Bigg) \cdot \sqrt{\psi_{st}} \qquad (3.254)$

$\Delta V_{th,all} = \Delta V_{th,SCE} + \Delta V_{th,DIBL} + \Delta V_{th,RSCE} + \Delta V_{th,temp} \qquad (3.255)$

$V_{gsfb} = V_{gs} - \Delta \phi - \Delta V_{th,all} - DVTSHIFT \qquad (3.256)$

BSIM-CMG provides an option to use $\Theta_{SW}$, $\Theta_{SS}$, $\Theta_{DIBL}$ and $\Theta_{DITS}$ as model parameters directly.