Battery mounted integrated circuit device having diffusion layers that prevent cations serving to charge and discharge battery from diffusing into the integrated circuit region

A battery mounted integrated circuit device, comprising:

• (1) a semiconductor substrate;
• (2) a solid state battery mounted on said semiconductor substrate;
• (3) an integrated circuit mounted on said semiconductor substrate;
• (4) a first diffusion layer, containing an N-type impurity, formed between a region of said semiconductor substrate where said solid state battery is mounted and a region of said semiconductor substrate where said integrated circuit is mounted;
• and
• (5) a second diffusion layer, containing an N-type impurity, formed below said region of said semiconductor substrate where said solid state battery is mounted, and overlapping with said first diffusion layer, wherein:
• said solid state battery comprises a positive electrode, a negative electrode, and a solid electrolyte disposed between said positive electrode and said negative electrode,
• the concentration of said N-type impurity in said first diffusion layer is higher than the concentration of said N-type impurity in said second diffusion layer,
• at least when said solid state battery is being charged and discharged, said first diffusion layer and said second diffusion layer have a positive potential not less than the potential of the positive electrode with respect to the negative electrode,
• said solid state battery is carried on the second diffusion layer, and
• said first diffusion layer surrounds said region where said solid state battery is mounted.