TW201511242A - Image sensor - Google Patents

Abstract

A image sensor is disclosed in this invention, including a micro lens set, a color filter set and a semiconductor substrate. The micro lens includes a first lens unit and a second lens unit. The color filter set includes a first color filtering unit and a second color filtering unit, Wherein the first lens unit and the second lens unit are disposed upon the first color filtering unit and the second color filtering unit respectively, and the curvatures of the first lens unit and the second lens unit are designated in accordance with the first color filtering unit and the second color filtering unit. The semiconductor substrate includes a first photosensitive unit and a second photosensitive unit corresponding to the first color filtering unit and the second color filtering unit respectively.

Description

Image sensing device

Embodiments of the present invention relate to image sensing devices, and more particularly to an optical device for assisting in correcting filtering.

With the rapid development of communication systems, many electronic devices are equipped with photographing or photography functions, especially portable electronic devices (such as smart phones or notebook computers), but users of this type of products Under the extremely thin and light requirements, the volume of the camera module is getting smaller and smaller, and the number of pixels is getting higher and higher, so the manufacturing difficulty is getting higher and higher. Moreover, in the case where the number of small pixels is increased, it is more difficult to improve the image quality. Therefore, how to improve the above problems has become a very important issue in this field.

One of the objects of the present invention is to provide an image sensing device, and more particularly to an optical device for assisting in correcting filtering to solve the above problems.

According to a first embodiment of the present invention, there is provided an image sensing apparatus comprising a microlens group, a color filter set, and a semiconductor substrate. The microlens group includes a first lens unit and a second lens unit. The color filter set includes a first color filter unit and a second color filter unit. The first lens unit and the second lens unit are respectively disposed on the first color filter unit and the second color filter unit, and the curvature systems of the first lens unit and the second lens unit are respectively It is set according to the first color filter unit and the second color filter unit. The semiconductor substrate includes a first photosensitive unit and a second photosensitive unit, Corresponding to the first color filter unit and the second color filter unit, respectively.

In summary, the image sensing device of the present invention can improve the deviation caused by the difference in the absorption position of light of different colors in the photosensitive layer, and at the same time make the arrangement between the pixel units more compact, thereby improving the The effect of the camera module and the reduction of its area.

102, 108, 114, 202, 208, 214‧‧ ‧ microlenses

104, 110, 116, 204, 210, 216‧‧ filter units

106, 112, 118, 206, 212, 218‧‧ ‧ photosensitive layer

10, 20‧‧‧Microlens group

12, 22‧‧‧ color filter group

13, 23‧‧‧ Winding layer

14, 24‧‧‧ Semiconductor substrate

130, 230‧‧‧ metal layer

132, 232‧‧‧ dielectric layer

200‧‧‧Image sensing device

302, 304, 306‧‧‧Microlens semi-finished products

Figure 1 is a schematic diagram of a conventional camera module.

2 is a schematic view of an embodiment of an image sensing device of the present invention.

FIG. 3 is a schematic view showing a process of using a gray scale mask for the image sensing device of the present invention.

Certain terms are used throughout the description and following claims to refer to particular elements. It should be understood by those of ordinary skill in the art that manufacturers may refer to the same elements by different nouns. The scope of this specification and the subsequent patent application do not use the difference of the names as the means for distinguishing the elements, but the difference in function of the elements as the criterion for distinguishing. The term "including" as used throughout the specification and subsequent claims is an open term and should be interpreted as "including but not limited to".

Please refer to FIG. 1 , which is a schematic diagram of a conventional image sensing device. The image sensing device includes a microlens group 10, a color filter group 12, a winding layer 13 and a semiconductor substrate 14 to form a sensing array. The microlens group 10 includes microlenses 102, 108, and 114. The color filter set 12 includes filter units 104, 110, and 116. The winding layer 13 includes a metal layer 130 and a dielectric layer 132. The semiconductor substrate 14 includes photosensitive cells 106, 112, 118, as well as other circuit elements not shown and the like. The sensing array includes a plurality of pixels corresponding to different colors, such as blue pixels, green pixels, and red pixels. In this example, the blue pixel includes a micro lens 102, a filter unit (eg, a blue filter) 104, and a photosensitive unit 106; the green pixel includes a microlens 108, A filter unit (for example, a green filter) 110 and a photosensitive unit 112; the red pixel includes a microlens 114, a filter unit (for example, a red filter) 116, and a photosensitive unit 118. It is known from experiments that the position of the absorption region in the photosensitive unit 106 of the blue pixel is the shallowest, and the position of the absorption region in the photosensitive unit 112 of the green pixel is relatively intermediate, and the photosensitive unit 118 of the red pixel The absorption zone in the middle is the deepest. Since the prior art does not have different specifications for the microlenses of different color pixels, the conventional method cannot accurately focus the light of different colors to the depth of the corresponding absorption region, thus affecting Sensitive effect. In addition, in the past, it was limited by the process, and there must be a distance between the lenses, which could not be closely arranged, so that the volume in the camera module was affected.

Please refer to FIG. 2 , which is a schematic diagram of an embodiment of the image sensing device 200 of the present invention. The image sensing device 200 includes a microlens group 20, a color filter group 22, a winding layer 23, and a semiconductor substrate 24 to form a sensing array. The microlens group 20 includes microlenses 202, 208, and 214. The color filter set 22 includes filter units 204, 210, and 216. The winding layer 23 includes a metal layer 230 and a dielectric layer 232. The semiconductor substrate 24 includes photosensitive cells 206, 212, 218, as well as other circuit components not shown and the like. In this embodiment, the sensing array includes a plurality of pixels that can sense light of different colors, such as blue pixels, green pixels, and red pixels. The blue pixel includes a lens unit (for example, a micro lens 202), a filter unit (for example, a blue filter) 204, and a photosensitive unit 206; the green pixel includes a lens unit (for example, a microlens 208). a filter unit (such as a green filter) 210 and a photosensitive unit 212; and the red pixel includes a lens unit (such as a microlens 214), a filter unit (such as a red filter) 216, and a photosensitive unit 218. As can be seen from FIG. 2, the position of the absorption region in the photosensitive layer 206 of the blue pixel is the shallowest (for example, 0.32 um), and the position of the absorption region in the photosensitive layer 212 of the green pixel is relatively the middle. (for example, 0.79 um), and the position of the absorption region in the photosensitive layer 218 of the red pixel is the deepest (for example, 3.0 um). However, unlike the conventional structure of FIG. 1 , in this embodiment, the corresponding microlens is designed according to the depth of the absorption region position of the different color pixels in the photosensitive layer, specifically In other words, in order to focus the light of the blue pixel on the blue light absorbing region shown in the figure, the focus position of the light of the blue pixel can be adjusted by controlling the curvature of the microlens 202 of the blue pixel. Up to the blue light absorbing region in Fig. 2; a similar method is also used to control the green pixel and the red pixel, and therefore, based on the different positions of the absorbing regions, the final result is the curvature of the microlens 202 > micro The curvature of the lens 208 > the curvature of the microlens 214.

For example, a gray scale mask process can be used to control the area ratio of the microlens. Please refer to FIG. 3, which is a schematic diagram of a gray scale mask process for the image sensing device of the present invention. FIG. 3 illustrates a microlens semi-finished product 302 corresponding to a blue pixel, a microlens semi-finished product 304 corresponding to a green pixel, and a microlens semi-finished product 306 corresponding to a red pixel. Compared with the conventional process, the gray scale mask process has a higher resolution, so the degree of control of the specifications of the microlens is high, and the arrangement distance between the lenses can also be reduced. Therefore, by adopting the gray scale mask process, the lens units (for example, the microlenses 202, 208, 214) corresponding to different colors shown in FIG. 2 can be made continuous without gaps.

Note that the above-described embodiments are described with respect to blue pixels, green pixels, and red pixels, however, this is not a limitation of the present invention. In addition, the gray scale mask process described above is used for illustrative purposes only, and is not a limitation of the present invention, and any other method that achieves the same effect is within the scope of the present invention.

In summary, the image sensing device of the present invention can improve the deviation caused by the difference in the absorption position of light of different colors in the photosensitive layer, and at the same time make the arrangement between the pixel units more compact, thereby improving the The effect of the camera module and the reduction of its area.

The above are only the preferred embodiments of the present invention, and all changes and modifications made to the scope of the present invention should be within the scope of the present invention.

200‧‧‧Image sensing device

202, 208, 214‧‧‧ microlens

204, 210, 216‧‧‧ filter unit

206, 212, 218‧‧‧Photosensitive layer

20‧‧‧Microlens group

22‧‧‧Color Filter Set

23‧‧‧Winding layer

24‧‧‧Semiconductor substrate

230‧‧‧metal layer

232‧‧‧Dielectric layer

Claims (8)

An image sensing device includes: a microlens group including: a first lens unit; and a second lens unit; a color filter set including: a first color filter unit; and a first a second color filter unit; wherein the first lens unit and the second lens unit are respectively disposed on the first color filter unit and the second color filter unit, and the first lens unit and the second The respective curvatures of the lens units are set according to the first color filter unit and the second color filter unit; a semiconductor substrate includes a first photosensitive unit and a second photosensitive unit, respectively corresponding to the first color filter a light unit and the second color filter unit. The image sensing device of claim 1, wherein the first color filter unit and the second color filter unit respectively correspond to different colors. The image sensing device of claim 1, wherein the first color filter unit and one of the second color filter units are a red filter unit. The image sensing device of claim 1, wherein the first color filter unit and one of the second color filter units are a green filter unit. The image sensing device of claim 1, wherein the first color filter unit and one of the second color filter units are a blue filter unit. The image sensing device of claim 1, further comprising: a third lens unit; wherein the first lens unit, the second lens unit and the third lens unit are respectively disposed on a red filter unit And a green filter unit and a blue filter unit, wherein the curvature of the first lens unit is smaller than the curvature of the second lens unit, and the curvature of the second lens unit is smaller than the curvature of the third lens unit. The image sensing device of claim 1, wherein the first lens unit and the second lens unit are continuous without gaps. The image sensing device of claim 1, wherein the first lens unit and the second lens unit are implemented by a gray scale mask process.