Solid state image pickup device and method for manufacturing solid state image pickup device

A solid state image pickup device comprising:

• a plurality of pixels, each including
• a conversion unit to generate signal carriers and
• at least one pixel transistor to read signals based on the generated signal carriers;
• a first active region provided with a first conversion unit;
• a second active region provided with a second conversion unit;
• and
• a third active region adjoining the first and the second active regions with a field region therebetween and being provided with the pixel transistor,
• wherein a first conductivity type first semiconductor region serving as a potential barrier against the signal carriers is disposed at a predetermined depth in the third active region,
• second conductivity type impurity ions are disposed at a position shallower than a position of the first semiconductor region and in a channel portion of the pixel transistor disposed in the third active region,
• the first conductivity type is opposite of the second conductivity type, and
• the channel portion of the pixel transistor is disposed between a source region and a drain region of the pixel transistor.

A method for manufacturing a solid state image pickup device including:

• a semiconductor substrate,
• a photoelectric conversion unit configured to generate a signal carrier, and
• at least one pixel transistor configured to read a signal based on a signal carrier generated by the a photoelectric conversion unit,
• the method comprising:
• implanting a first conductivity type impurity ions into the semiconductor substrate in order to form a semiconductor region serving as a potential barrier against the signal carrier;
• and
• implanting a second conductivity type impurity ions into a region serving as a channel portion of the pixel transistor, with a lower energy than an implantation energy of the implanting of the first conductivity type impurity ions,
• wherein the first conductivity type is opposite of the second conductivity type,
• wherein the channel portion of the pixel transistor is provided between a source region and a drain region of the pixel transistor, and
• wherein an insulating material is formed between the photoelectric conversion unit and the pixel transistor.

A method for manufacturing a solid state image pickup device including:

• a semiconductor substrate,
• a photoelectric conversion unit configured to generate a signal carrier, and
• at least one pixel transistor configured to read a signal based on a signal carrier generated by the a photoelectric conversion unit and provided in an active region of the semiconductor substrate,
• the method comprising:
• implanting a first conductivity type impurity ions into the active region, where the pixel transistor is to be or has been provided;
• and
• implanting a second conductivity type impurity ions into a region serving as a channel portion of the pixel transistor, with a lower energy than an implantation energy of the implanting of the first conductivity type impurity ions,
• wherein the first conductivity type is opposite of the second conductivity type,
• wherein the channel portion of the pixel transistor is provided between a source region and a drain region of the pixel transistor, and
• wherein an insulating material is formed between the photoelectric conversion unit and the pixel transistor.