The invention provides an
image sensor adopting deep groove isolation and a manufacturing method thereof. The method at least comprises the following steps that a substrate is provided; an isolation structure of an isolation pixel unit is formed on the substrate; an epitaxial
monocrystalline silicon layer covering the isolation structure is formed in a selective
epitaxy mode; partial devices of the
image sensor are formed in the epitaxial
monocrystalline silicon layer. The deep groove isolation structure is formed before an
image sensor device is formed, the isolation structure has better
surface shape and fewer defects, in addition, the restoration can be carried out through the
epitaxy high-temperature process, and the influence of defects is further eliminated, so that the interface of the isolation structure is more excellent, and the deep groove isolation structure is formed before the device is made, so the selectivity of process means and environment is wider, the damage to the device does not need to be considered, the epitaxial
monocrystalline silicon layer is used for forming the device grows after the isolation
structure formation, the condition that no stress is conducted into a
silicon device is ensured through a high-temperature manufacture procedure, and the performance of the image sensor device is ensured.