First Vertically Stacked, Compressively Strained, and Triangular Ge0.91Sn0.09pGAAFETs with High $\mathbf{I_{ON}}$ of $\mathbf{19.3}\mu \mathbf{A}\ \mathbf{at}\ \mathbf{V_{OV}}=\mathbf{V}_{\mathbf{DS}}=\mathbf{-0.5V},\ \mathbf{G}_{\mathbf{m}}$ of $\mathbf{50.2}\mu \mathbf{S}$ at $\mathbf{V_{DS}}=\mathbf{-0.5}\mathbf{V}$ and Low $\mathbf{SS_{lin}}$ of 84m V/dec by CVD Epitaxy and Orientation Dependent Etching

The natural etching stop on {111} facets yields the small dangling bond density and roughness, enabling low SS and high ION on {111} sidewalls of the GAA channels. In addition, the ~ 2% uniaxial compressive strain and [Sn]=9% in the channel can reduce the hole effective mass. As a result, 50% improvement of I
_ON
= 120μA/μm (perimeter), and 71% improvement of G
_m
=312μS/μm are achieved than our previous 3 stacked GeSn {001} nanosheets. Record high I
_ON
of 19.3μA per stack at V
_OV
=V
_DS
=-0.5V and record G
_m
of 50.2μS per stack at V
_DS
=-0.5V among all GeSn FinFETs and GAAFETs are achieved. The SS
_lin
as low as S4mV/dec is also obtained, 22% reduction than our previous work.