There are different features sizes in the Z direction and different feature sizes in the XY plane. When it comes to XY, the smallest features size is probably t

There are different features sizes in the Z direction and different feature sizes in the XY plane. When it comes to XY, the smallest features size is probably the gate length. When it comes to Z, the gate oxide width is probably the smallest at 1-2nm. We have something called atomic layer deposition which gives control over single atomic layer thicknesses.