CMOS-Compatible Self-Aligned In0.53Ga0.47As MOSFETs With Gate Lengths Down to 30 nm

We demonstrate self-aligned fully-depleted 20-nm-thick In
_0.53
Ga
_0.47
As-channel MOSFETs using CMOS-compatible device structures and manufacturable process flows. These devices consist of self-aligned source/drain extensions and self-aligned raised source/drain with low sheet resistance of 360 and 115 Ω/sq, respectively. We demonstrate short-channel MOSFETs with gate lengths L
_G
down to 30 nm, low series resistance R
_EXT
= 375 Ω·μm, and high peak saturation transconductance G
_MSAT
= 1275 μS/μm at L
_G
= 50 nm and drain bias V
_DS
= 0.5 V. We obtain long-channel capacitive inversion thickness TINV = 2.3 nm and effective mobility μ
_EFF
= 650 cm
²
/Vs at sheet carrier density N
_S
= 5 × 10
¹²
cm
^-2
. Finally, using a calibrated quasi-ballistic FET model, we argue that for L
_G
≤ 20 nm, μ
_EFF
≈ 1000 cm
²
/Vs will lead to short-channel MOSFETs operating within 10% of the ballistic limit. Thus, our III-V processes and device structures are well-suited for future generations of high-performance CMOS applications at short gate lengths and tight gate pitches.