IMAGE SENSOR AND METHOD FOR MANUFACTURING THE SAME

• Main Author: KUMAI KOICHI
• Format: Patent
• Language: English; Japanese
• Published: 17.05.2018
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

PROBLEM TO BE SOLVED: To provide: an image sensor which enables the rise in the light sensitivity of each pixel; and a method for manufacturing such an image sensor.SOLUTION: The image sensor comprises a photoelectric conversion element 3 and a micro lens 1 which are stacked on a silicon wafer 4 in this order. In the image sensor, respective pixels of green, blue and red colors are formed. The depth of focus of the micro lens 1 over the blue pixel is located at a position 200-500 nm-deep in the photoelectric conversion element 3 from a surface of the photoelectric conversion element on the side of the micro lens 1 toward a film thickness direction of the photoelectric conversion element 3. The depth of focus of the micro lens 1 over the green pixel is located at a position 600-900 nm-deep in the photoelectric conversion element 3 from the surface of the photoelectric conversion element 3 on the side of the micro lens 1 toward the film thickness direction of the photoelectric conversion element 3. The depth of focus of the micro lens 1 over the red pixel is located at a position 2000-2500 nm-deep in the photoelectric conversion element 3 from the surface of the photoelectric conversion element 3 on the side of the micro lens 1 toward the film thickness direction.SELECTED DRAWING: Figure 1 【課題】各画素の受光感度を向上させ得るイメージセンサおよびその製造方法を提供する。【解決手段】このイメージセンサは、シリコンウエハ４上に、光電変換素子３およびマイクロレンズ１がこの順に積層され、グリーン、ブルーおよびレッドの各画素が形成される。ブルー画素上のマイクロレンズ１の焦点深さは、光電変換素子３におけるマイクロレンズ１側の表面から光電変換素子３の膜厚方向に向かって２００〜５００ｎｍ内側の位置にある。グリーン画素上のマイクロレンズ１の焦点深さは、光電変換素子３におけるマイクロレンズ１側の光電変換素子３の表面から光電変換素子３の膜厚方向に向かって６００〜９００ｎｍ内側の位置にある。レッド画素上のマイクロレンズ１の焦点深さは、光電変換素子３におけるマイクロレンズ１側の光電変換素子３の表面から膜厚方向に向かって２０００〜２５００ｎｍ内側の位置にある。【選択図】図１