Patent ID: 7993952

Claim:
A method of making a charge transfer device which comprises a P-type region, an N-type well formed in the P-type region, and transfer electrodes provided over the N-type well while placing an insulating film in between, each of the transfer electrodes including a storage electrode and a barrier electrode, the storage electrode being provided as a P-type polysilicon that is formed on the insulating film, comprising: examining a potential difference between a potential of the N-type well under the storage electrode being provided as an N-type polysilicon and a potential of the N-type well under the storage electrode being provided as a P-type polysilicon on condition that the N-type well has a first impurity concentration and the same potential is applied to the N-type polysilicon and the P-type polysilicon; and setting an impurity concentration of the N-type well to a second impurity concentration so that a potential of the N-type well having the second impurity concentration under the storage electrode being provided as the P-type polysilicon is substantially equal to the potential of the N-type well having the first concentration under the storage electrode being provided as the N-type polysilicon.