Solid-state imaging device, fabrication method thereof, imaging apparatus, and fabrication method of anti-reflection structure

A fabrication method of a solid-state imaging device, the method comprising the steps of:

• forming an interlayer insulating film on a semiconductor substrate, in which a photoelectric conversion portion that converts an incident light to signal charges and a charge transfer portion that reads out and transfers the signal charges from the photoelectric conversion portion are formed, and forming a planarization insulating film thereon;
• forming a resin film having micro-particles dispersed therein on the planarization insulating film;
• forming a protrusion dummy pattern on the resin film by etching the resin film using the micro-particles in the resin film as a mask while gradually etching the micro-particles;
• and
• forming a protrusion pattern on the surface of the planarization insulating film by etching back the surface of the planarization insulating film together with the resin film having the protrusion dummy pattern formed thereon, and transferring a surface shape of the protrusion dummy pattern formed on a surface of the resin film to the surface of the planarization insulating film.

A fabrication method of a solid-state imaging device, the method comprising the steps of:

• forming an interlayer insulating film on a semiconductor substrate, in which a photoelectric conversion portion that converts an incident light to signal charges and a charge transfer portion that reads out and transfers the signal charges from the photoelectric conversion portion are formed, and forming a planarization insulating film thereon;
• arranging micro-particles on a surface of the planarization insulating film;
• and
• forming a protrusion pattern on the surface of the planarization insulating film by performing anisotropic etching in which an etching rate for the planarization insulating film is higher than an etching rate for the micro-particles.

A solid-state imaging device comprising:

• a photoelectric conversion portion that is disposed in a semiconductor region so as to obtain signal charges by performing photoelectric conversion on an incident light;
• and
• a plurality of layers of light transmissive films formed on the photoelectric conversion portion,
• wherein an anti-reflection structure is formed on a surface of the semiconductor region or a surface of a first light transmissive film on at least one layer of the plurality of layers of the light transmissive films;
• the anti-reflection structure is constructed from spindle-shaped protrusions which have light transmissive properties and a sinusoidal curved surface and are arranged on the surface of the first light transmissive film or the surface of the semiconductor region;
• and
• the protrusions have a height which is equal to or greater than 50 nm and equal to or less than 100 nm for an arrangement pitch of 40 nm, equal to or greater than 200 nm and equal to or less than 400 nm for an arrangement pitch of 100 nm, and equal to or greater than 50 nm and equal to or less than 400 nm for an arrangement pitch of 200 nm.

A fabrication method of a solid-state imaging device, the method comprising the step of:

• forming an anti-reflection structure on a surface of a first light transmissive film on at least one layer of a plurality of layers of light transmissive films when the plurality of layers of the light transmissive films are formed on a photoelectric conversion portion that is disposed in a semiconductor region so as to obtain signal charges by performing photoelectric conversion on an incident light
• wherein the anti-reflection structure forming step includes the steps of
• forming a UV-curable film on the surface of the first light transmissive film,
• transferring a shape of spindle-shaped protrusions having a sinusoidal curved surface to a surface of the UV-curable film by pressing a UV-transmitting nanoimprint mold, in which spindle-shaped depressions having a sinusoidal curved surface are arranged on an entire surface, against the UV-curable film,
• curing the UV-curable film by irradiation with ultraviolet rays in a state where the nanoimprint mold is pressed,
• separating the nanoimprint mold from the UV-curable film, and
• transferring a shape of spindle-shaped protrusions having a sinusoidal curved surface formed on the UV-curable film to the surface of the first light transmissive film by etching back the UV-curable film and an upper portion of the first light transmissive film, and
• the protrusions are formed to have a height which is equal to or greater than 50 nm and equal to or less than 100 nm for an arrangement pitch of 40 nm, equal to or greater than 200 nm and equal to or less than 400 nm for an arrangement pitch of 100 nm, and equal to or greater than 50 nm and equal to or less than 400 nm for an arrangement pitch of 200 nm.

A fabrication method of a solid-state imaging device, the method comprising the step of:

• forming an anti-reflection structure on a surface of a first light transmissive film on at least one layer of a plurality of layers of light transmissive films when the plurality of layers of the light transmissive films are formed on a photoelectric conversion portion that is disposed in a semiconductor region so as to obtain signal charges by performing photoelectric conversion on an incident light,
• wherein the anti-reflection structure forming step includes the steps of
• forming the first light transmissive film from a UV-curable or heat-curable coating film,
• transferring a shape of spindle-shaped protrusions having a sinusoidal curved surface to a surface of the first light transmissive film by pressing a UV-transmitting nanoimprint mold, in which spindle-shaped depressions having a sinusoidal curved surface are arranged on an entire surface, against the first light transmissive film,
• curing the first light transmissive film by irradiation with ultraviolet rays in a state where the nanoimprint mold is pressed, and
• separating the nanoimprint mold from the first light transmissive film, and
• the protrusions are formed to have a height which is equal to or greater than 50 nm and equal to or less than 100 nm for an arrangement pitch of 40 nm, equal to or greater than 200 nm and equal to or less than 400 nm for an arrangement pitch of 100 nm, and equal to or greater than 50 nm and equal to or less than 400 nm for an arrangement pitch of 200 nm.

An imaging apparatus comprising:

• a light-condensing optical unit that condenses an incident light;
• an imaging unit having a solid-state imaging device which receives the light condensed by the light-condensing optical unit and performs photoelectric conversion on the light;
• and
• a signal processing portion that processes signals having been subjected to the photoelectric conversion,
• wherein the solid-state imaging device includes
• a photoelectric conversion portion that is disposed in a semiconductor region so as to obtain signal charges by performing photoelectric conversion on an incident light, and
• a plurality of layers of light transmissive films formed on the photoelectric conversion portion;
• an anti-reflection structure is formed on a surface of the semiconductor region or a surface of a first light transmissive film on at least one layer of the plurality of layers of the light transmissive films;
• the anti-reflection structure is constructed from spindle-shaped protrusions which have light transmissive properties and a sinusoidal curved surface and are arranged on the surface of the first light transmissive film or the surface of the semiconductor region;
• and
• the spindle-shaped protrusions have a height which is equal to or greater than 50 nm and equal to or less than 100 nm for an arrangement pitch of 40 nm, equal to or greater than 200 nm and equal to or less than 400 nm for an arrangement pitch of 100 nm, and equal to or greater than 50 nm and equal to or less than 400 nm for an arrangement pitch of 200 nm.