A method for manufacturing a semiconductor device and semiconductor device. The apparatus comprises a hollow grow tube having a front face, a back face, a first end, and a second end. In particular, the first biasing terminal is connected to at least one input stage in correspondence with bulk terminals of MOS transistors comprised in the input stage and it is suitable for supplying it with a first negative voltage. The IP block developer can send or otherwise provide the IP block to another IP user without disclosing the functional description of the secret portion of the IP block.