I don't why we should refer to a tri-gate transistor as a "3D transistor". Truely three dimensional integrated circuits have multiple layers on the silicon substrate, so as the laying extends vertically as well. I know only one company that was doing this, Matrix Semiconductor, Inc, and they claim to be the pioneers of the 3-D integrated circuits. http://www.matrixsemi.com/. They are now acquired by SanDisk, Inc.