While real‐time and in‐situ process sensors have been effectively applied to fault detection, process control through course correction has been mainly focused on in‐line metrologies to drive run‐to‐run feedback and feedforward control. We have developed in‐situ metrologies based on mass spectrometry, acoustic sensing, and FTIR techniques which enable real‐time thickness metrology and control in CVD processes at a level of about 1&percent; accuracy. These developments open the door to real‐time sensors as the basis for both fault management and course correction, i.e., for real‐time advanced process control. We have also employed in‐situ metrology to develop robust control schemes for CVD precursor delivery from solid sources, and we are exploring a new spatially programmable reactor design paradigm for which real‐time, in‐situ sensing, metrology, and control of across‐wafer uniformity is fundamental. © 2003 American Institute of Physics