Solid-state imaging device, method for manufacturing the same and interline transfer CCD image sensor

A method for manufacturing a solid-state imaging device comprising a plurality of pixel cells arranged in a matrix form on a semiconductor substrate;

• wherein each of the plurality of pixel cells comprises:
• a photodiode;
• at least one MOS transistor that is provided for reading out the signal charge stored in the photodiode;
• an element isolation portion that isolates the photodiode and the MOS transistor from each other;
• and a deep-portion isolation implantation layer that is formed under the element isolation portion, and
• wherein the semiconductor substrate comprises:
• a n-type substrate;
• a first p-type well that is formed so as to enclose the photodiode, the element isolation portion and side faces and a bottom face of the deep-portion isolation implantation layer;
• and a second p-type well that is formed between the n-type substrate and the first p-type well and has an impurity density higher than an impurity density of the first p-type well,
• the method comprising the steps of:
• grooving the semiconductor substrate so as to form a groove for the formation of the element isolation portion;
• implanting an impurity from a bottom of the groove so as to form the deep-portion isolation implantation layer;
• forming the element isolation portion in the groove after the impurity implantation step;
• and
• forming the photodiode and the at least one MOS transistor after the element isolation portion formation step.

A method for manufacturing a solid-state imaging device comprising a plurality of pixel cells arranged in a matrix form on a semiconductor substrate;

• wherein each of the plurality of pixel cells comprises:
• a photodiode;
• at least one MOS transistor that is provided for reading out the signal charge stored in the photodiode;
• an element isolation portion that isolates the photodiode and the MOS transistor from each other;
• and a deep-portion isolation implantation layer that is formed under the element isolation portion,
• wherein the semiconductor substrate comprises:
• a n-type substrate;
• a first p-type well that is formed so as to enclose the photodiode, the element isolation portion and side faces and a bottom face of the deep-portion isolation implantation layer;
• and a second p-type well that is formed between the n-type substrate and the first p-type well and has an impurity density of the first p-type well, and
• wherein the photodiode comprises:
• a surface shield layer that is formed at a surface of the semiconductor substrate;
• and a storage photodiode layer that is formed under the surface shield layer, with an impurity of the deep-portion isolation implantation layer being larger than an impurity density higher than an impurity density of the storage photodiode layer,
• the method comprising the steps of:
• grooving the semiconductor substrate so as to form a groove for the formation of the element isolation portion;
• implanting an impurity from a bottom of the groove so as to form the deep-portion isolation implantation layer;
• forming the element isolation portion in the groove after the impurity implantation step;
• and
• forming the photodiode and the at least one MOS transistor after the element isolation portion formation step.

A method for manufacturing a solid-state imaging device comprising a plurality of pixel cells arranged in a matrix form on a semiconductor substrate;

• wherein each of the plurality of pixel cells comprises:
• a photodiode;
• at least one MOS transistor that is provided for reading out the signal charge stored in the photodiode;
• an element isolation portion that isolates the photodiode and another photodiode included in a pixel cell adjacent the pixel cell including the photodiode from each other;
• and a deep-portion isolation implantation layer that is formed under the element isolation portion, and
• wherein the semiconductor substrate comprises:
• a n-type substrate;
• a first p-type well that is formed so as to enclose the photodiode, the element isolation portion and side faces and a bottom face of the deep-portion isolation implantation layer;
• and a second p-type well that is formed between the n-type substrate and the first p-type well and has an impurity density higher than an impurity density of the first p-type well,
• the method comprising the steps of:
• grooving the semiconductor substrate so as to form a groove for the formation of the element isolation portion;
• implanting an impurity form a bottom of the groove so as to form the deep-portion isolation implantation layer;
• forming the element isolation portion in the groove after the impurity implantation step;
• and
• forming the photodiode and the at least one MOS transistor after the element isolation portion formation step.

A method for manufacturing an interline transfer CCD image sensor comprising a plurality of pixel cells arranged in a matrix form on a semiconductor substrate;

• wherein each of the plurality of pixel cells comprises:
• a photodiode that converts incident light into a signal charge and stores the signal charge;
• a transfer gate that is provided for reading out the signal charge stored in the photodiode;
• an element isolation portion that isolates the photodiode and the transfer gate from each other;
• vertical transfer CCDs that are arranged at predetermined intervals and along a vertical direction so as to be adjacent to the representative pixel cells that are arranged along a column direction, the vertical transfer CCDs being provided for transferring the signal charge read out from the photodiode by the transfer gate along the vertical direction;
• and a deep-portion isolation implantation layer that is formed under the element isolation portion, and
• wherein the semiconductor substrate comprises:
• a n-type substrate;
• a first p-type well that is formed so as to enclose the photodiode, the element isolation portion and side faces and a bottom face of the deep-portion isolation implantation layer;
• and a second p-type well that is formed between the n-type substrate and the first p-type well and has an impurity density higher than an impurity density of the first p-type well,
• the method comprising the steps of:
• grooving the semiconductor substrate so as to form a groove for the formation of the element isolation portion;
• implanting an impurity from a bottom of the groove so as to form the deep-portion isolation implantation layer;
• forming the element isolation portion in the groove after the impurity implantation step;
• and
• forming the photodiode and the at least on MOS transistor after the element isolation portion formation step.