TWI664450B - Optical sensor and method for forming the same - Google Patents

Abstract

An embodiment of the present invention provides an optical sensor including a plurality of pixels in a substrate and a light collimation layer on the substrate. The light collimation layer includes a light-shielding layer, a light-transmitting post, and a first dummy light-transmitting post. The light shielding layer is located on the substrate. The light-transmitting column passes through the light-shielding layer and is correspondingly disposed on the pixel. The first dummy light-transmitting column passes through the light shielding layer and is located in a first peripheral region of the light collimation layer. The first dummy light-transmitting column surrounds the light-transmitting column in the upper view.

Description

Optical sensor and forming method thereof

The present invention relates to an optical element, and more particularly to an optical sensor.

The optical elements in the optical sensor may include a light collimator, a beam splitter, a focusing lens, and a linear sensor. Among them, the function of the light collimator is to collimate the light to reduce the energy loss caused by the light divergence. For example, a light collimator can be used in an optical sensor to increase the performance of a fingerprint recognition device.

The light collimator includes a light-transmitting post and a light-shielding layer surrounding the light-transmitting post to achieve the effect of collimating light. However, in the process of making the light collimator, the light-transmitting pillars located at the edge of the light-transmitting pillar array are easily collapsed due to their own cohesion or the stress of the light-shielding layer, which affects the collimation effect of the light collimator and further affects the optical sensor rate.

Although the existing optical sensors generally meet the requirements, they are not satisfactory in all aspects. In particular, the structural strength of the optical collimator for optical sensors needs to be further improved.

According to an embodiment, the present invention provides an optical sensor including: a pixel located in a substrate; and a light collimating layer located on a substrate. It includes: a light-shielding layer located above the substrate; a light-transmitting column passing through the light-shielding layer and correspondingly disposed on the pixel; a first dummy light-transmitting column passing through the light-shielding layer and located at a first peripheral region of the light collimation layer ; Wherein the first dummy light transmitting column surrounds the light transmitting column in the upper view.

According to another embodiment, the present invention provides a method for forming an optical sensor, including: forming pixels in a substrate; forming a light collimation layer on the substrate, wherein forming the light collimation layer includes: forming a light-transmitting pillar and A first dummy transparent pillar is disposed on the substrate, wherein the transparent pillar is correspondingly arranged on the pixel, and the first dummy transparent pillar is located in a first peripheral region of the light collimation layer; a light shielding layer is formed on the transparent pillar and the Between the first dummy light transmitting pillars; wherein the first dummy light transmitting pillars surround the light transmitting pillars in the top view.

In order to make the above-mentioned objects, features, and advantages of the present invention more comprehensible, several embodiments are described below in detail, in conjunction with the accompanying drawings, as follows.

100, 200, 300, 400, 500‧‧‧ optical sensors

102‧‧‧ substrate

104C‧‧‧Central Area

104P‧‧‧First surrounding area

106‧‧‧ pixels

108‧‧‧light transmission column

108D‧‧‧The first dummy light transmission column

110‧‧‧Light-shielding layer

112‧‧‧light collimation layer

208D‧‧‧The first dummy light transmission column

308D‧‧‧The first dummy light transmission column

408D1‧‧‧The first dummy light transmission column

408D2‧‧‧Second virtual transmission column

404P1‧‧‧The first surrounding area

404P2‧‧‧Second Peripheral Area

504P3‧‧‧ Third peripheral area

508D3‧‧‧th third dummy light transmission column

AA’‧‧‧ Segment

W, DW‧‧‧Width

P, DP‧‧‧ pitch

X, Y‧‧‧ directions

DW1, DW2‧‧‧Width

DP1, DP2 ‧‧‧ pitch

The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, in accordance with standard practice in the industry, various features are not drawn to scale and are for illustration purposes only. In fact, it is possible to arbitrarily enlarge or reduce the size of the element to clearly show the characteristics of the embodiment of the present invention.

1A, 2A, and 3A are schematic cross-sectional views illustrating different stages of forming an optical sensor according to some embodiments.

1B, 2B, and 3B are top views illustrating different stages of forming an optical sensor according to some embodiments.

FIG. 4 is a top view illustrating an optical sensor according to other embodiments.

FIG. 5 is a top view illustrating an optical sensor according to still other embodiments.

FIG. 6 is a top view illustrating an optical sensor according to still other embodiments.

FIG. 7 is a top view illustrating an optical sensor according to other embodiments.

Many different implementation methods or examples are disclosed below to implement the different features of the embodiments of the present invention. The following describes specific embodiments of the elements and their arrangements to illustrate the embodiments of the present invention. Of course, these embodiments are only for illustration, and the scope of the embodiments of the present invention should not be limited by this. For example, it is mentioned in the description that the first feature is formed on the second feature, which includes the embodiment in which the first feature and the second feature are in direct contact, and also includes the other between the first feature and the second feature. An embodiment of a feature, that is, the first feature and the second feature are not in direct contact. In addition, repeated reference numerals or signs may be used in different embodiments. These repetitions are only for simply and clearly describing the embodiments of the present invention, and do not represent a specific relationship between the different embodiments and / or structures discussed.

In addition, space-relative terms may be used, such as "below", "below", "lower", "above", "higher" and similar terms. These spaces are relatively relative Words are used to facilitate the description of the relationship between one or more elements or features and other elements or features in the illustration. These spatial relative terms include the different positions of the device in use or operation, and in the drawings. The described orientation. When the device is turned to different orientations (rotated 90 degrees or other orientations), the spatially relative adjectives used in it will also be interpreted according to the orientation after turning.

Here, the terms "about", "approximately", and "mostly" generally indicate within a given value or range within 20%, preferably within 10%, and more preferably within 5%, or 3 Within%, or within 2%, or within 1%, or within 0.5%. It should be noted that the quantity provided in the description is an approximate quantity, that is, the "about", "approximately", "approximately", "approximately", " "Maybe."

Although the steps in some of the embodiments described are performed in a particular order, these steps may also be performed in other logical orders. In different embodiments, some of the steps described may be replaced or omitted, and some other operations may be performed before, during, and / or after the steps described in the embodiments of the present invention. The optical sensor in the embodiment of the present invention may add other features. In different embodiments, some features may be replaced or omitted.

An embodiment of the present invention provides an optical sensor. In addition to correspondingly providing an array of light-transmitting columns above the pixel array in the collimation layer, a dummy light-transmitting column is provided on the periphery of the light-transmitting column. The dummy light transmission column can strengthen the structure of the light transmission column array, avoid deformation and collapse of the light transmission column at the edge of the light transmission column array, improve the uniformity of the light transmission column array, and improve the process yield.

1A, 2A, and 3A are schematic cross-sectional views illustrating different stages of forming the optical sensor 100 according to some embodiments. 1B, 2B, and 3B are top views illustrating different stages of forming the optical sensor 100 according to some embodiments. Figures 1A, 2A, and 3A are sectional views taken along line AA 'in Figures 1B, 2B, and 3B.

As shown in FIGS. 1A and 1B, a substrate 102 is provided. The substrate 102 may be a semiconductor substrate, such as a silicon substrate. In addition, the above semiconductor substrate may also be an element semiconductor, including germanium; a compound semiconductor, including nitride Gallium nitride (GaN), silicon carbide, gallium arsenide, gallium phosphide, indium phosphide, indium arsenide, and / or antimony Indium antimonide; alloy semiconductors, including silicon germanium alloy (SiGe), phosphorous arsenic gallium alloy (GaAsP), aluminum arsenic alloy (AlInAs), aluminum arsenic alloy (AlGaAs), indium gallium alloy (GaInAs), Indium gallium phosphate (GaInP), and / or indium gallium phosphorus arsenide (GaInAsP), or a combination of the foregoing materials. In some embodiments, the substrate 102 may also be a semiconductor on insulator substrate. The above-mentioned insulating semiconductor substrate may include a base plate, a buried oxide layer provided on the base plate, or a buried oxide layer. Semiconductor layer. In addition, the substrate 102 may be an N-type or a P-type conductive type.

In some embodiments, the substrate 102 may include various isolation components (not shown) for defining an active region and electrically isolating active region elements in / on the substrate 102. In some embodiments, the isolation component includes a shallow trench isolation (STI) component, a local oxidation of silicon (LOCOS) component, other suitable isolation components, or a combination thereof. In some embodiments, forming the isolation component may include, for example, forming an insulating layer on the substrate 102, selectively etching the insulating layer and the substrate 102 to form a trench in the substrate 102, and growing a nitrogen-rich (eg, nitrogen oxide) in the trench. Silicon) liners, filling the trench with an insulating material (such as silicon dioxide, silicon nitride, or silicon oxynitride) in a deposition process, annealing the insulating material in the trench, and, for example, chemical mechanical polishing ( The chemical mechanical polishing (CMP) process performs a planarization process on the substrate 102 to remove excess insulating material, so that the insulating material in the trench is equal to the top surface of the substrate 102.

In some embodiments, the substrate 102 may include various P-type doped regions and / or N-type doped regions (not shown) formed by, for example, ion implantation and / or diffusion processes. In some embodiments, the doped region may form a transistor, a photodiode, or the like. However, the above-mentioned components are merely examples, and the present invention is not limited thereto.

In some embodiments, the substrate 102 may include various conductive components (for example, wires or vias) (not shown). For example, the conductive member may be formed of aluminum (Al), copper (Cu), tungsten (W), other appropriate conductive materials, the alloy described above, or a combination thereof.

As shown in FIGS. 1A and 1B, in some embodiments, the optical sensor 100 is divided into a central region 104C and a first peripheral region 104P. As shown in the top view in FIG. 1B, the first peripheral region 104P surrounds the central region 104C.

As shown in FIGS. 1A and 1B, in some embodiments, the substrate 102 may include a pixel 106. The pixel 106 may include a light sensor and a read out circuit. The light sensor may include a photodiode, a charged coupling device (CCD) sensor, a complementary metal-oxide-semiconductor (CMOS) image sensor, an active sensor, Passive sensors, other suitable sensors, or a combination thereof. The readout circuit may include a transfer transistor, a reset transistor, a source-follower transistor, a select transistor, one or more other suitable transistors. Crystal, or a combination of the above. The pixel 106 can convert the received light signal into an electronic signal by a light sensor, and read the electronic signal through a readout circuit. One pixel 106 may correspond to at least one light sensor, such as at least one photodiode. As shown in Figure 1B, pixels 106 are arranged in an array in the upper view and are located at In the central region 104C of the substrate 102. It is worth noting that the number and arrangement of the pixel 106 array shown in FIG. 1B is only an example, and the embodiment of the present invention is not limited thereto. The pixel 106 may be an array of any number of rows or columns or other Arrangement.

Next, as shown in FIGS. 2A and 2B, a transparent pillar 108 and a first dummy transparent pillar 108D are formed on the substrate 102. In some embodiments, a light-transmitting layer may be formed on the substrate 102 blanketly. In some embodiments, the light-transmitting layer may include a light-transmitting material having a light transmittance of greater than 80% for light having a wavelength of 200 nm to 1200 nm. The light-transmitting material may include a light-curing material, a heat-curing material, or a combination thereof. In some embodiments, the light-transmitting material may include, for example, poly (methyl methacrylate (PMMA), perfluorocyclobutyl (PFCB) polymer, polyimide, epoxy resin, others A suitable material, or a combination of the above. In some embodiments, spin coating, chemical vapor deposition, physical vapor deposition (such as evaporation or sputtering), electroplating, atomic layer deposition, other appropriate The method, or a combination thereof, deposits a light-transmitting material on the substrate 102.

Next, the transparent material of the substrate 102 is selectively removed. In some embodiments, a patterning process and an etching process are used to selectively remove the light-transmitting material to correspondingly form a light-transmitting pillar 108 above the pixel 106, and simultaneously form a first surrounding the light-transmitting pillar 108 in the first peripheral region 104P. The dummy light transmission column 108D. In some embodiments, the patterning process may include photoresist coating (such as spin coating), soft baking, mask alignment, exposure pattern, post-exposure baking, photoresist Development, washing, and drying (eg, hard baking), other suitable techniques, or a combination thereof. The etching process may include a dry etching process (e.g., Such as reactive ion etch (RIE), plasma etching, ion milling, wet etching process, or a combination thereof.

Next, as shown in FIGS. 3A and 3B, a light-shielding layer 110 is formed between the light-transmitting post 108 above the substrate 102 and the first dummy light-transmitting post 108D. In some embodiments, the light-shielding layer 110 may include a light-shielding material that has an absorbance greater than 80% for light having a wavelength of 200 nm to 1200 nm. The light-shielding material may include a light-curing material, a heat-curing material, or a combination thereof. In some embodiments, the light-shielding material includes a non-transparent photoresist, an ink, a molding compound, a solder mask, other suitable materials, or a combination thereof. In some embodiments, a light-shielding material may be disposed between the light-transmitting post 108 and the first dummy light-transmitting post 108D above the substrate 102, and a curing process such as a photo-curing process, a heat-curing process, or a combination thereof may be performed for curing. A light-shielding material forms a light-shielding layer 110.

As shown in FIGS. 3A and 3B, the light collimating layer 112 of the optical sensor 100 includes, for example, a light transmitting pillar 108, a first dummy light transmitting pillar 108D, and a light shielding layer 110. In some embodiments, the optical collimation layer 112 may include other optical elements such as color filters, glass, meniscus lenses, and the like (not shown). The incident light passes through the optical element above the light collimation layer 112 and passes through the light collimation layer 112 to illuminate the pixels 106. The aspect ratio of each of the transparent pillar 108 and the first dummy transparent pillar 108D is between 5: 1 and 20: 1. If the light-transmitting pillar 108 and the first dummy light-transmitting pillar 108D are too high, it is easy to deform and collapse. If the light transmission column 108 is too wide, it is easy to receive unnecessary incident light and it is difficult to achieve a collimation effect. If the first dummy transparent pillar 108D is too wide, a loading effect is likely to occur, and the yield is reduced.

In some embodiments, as shown in FIG. It is correspondingly arranged on the pixel 106, and the arrangement of the light transmitting columns 108 in the upper view is also an array. The light-transmitting column 108 may completely or partially cover the corresponding pixel 106. In this way, the light transmission column 108 can protect the pixels 106 and reduce or prevent the pixels 106 from being damaged and / or contaminated in subsequent processes. In some embodiments, as shown in FIG. 3B, the transparent pillar 108 is circular in shape in the top view. In this way, compared with other patterns of the same diameter, the light-transmitting column 108 covers a larger area, which can further increase the amount of light received by the lower pixel 106 and further protect the corresponding pixel 106.

In some embodiments, as shown in FIG. 3A, the lower portion of the first dummy transparent pillar 108D does not correspond to any pixel 106. Since the light-transmitting pillars 108 are arranged in an array in the top view, the light-transmitting pillars 108 at the edge of the array may be deformed and collapsed due to cohesion between the molecules of the light-transmitting material or subsequent processing. By providing a first dummy light transmission column 108D on the edge of the light transmission column 108 array as a stress buffer to provide physical support, the structure of the light transmission column 108 array can be strengthened to prevent deformation and collapse of the light transmission column 108 on the edge of the array and maintain the light transmission column. The uniformity of 108 improves the yield.

In some embodiments, as shown in FIG. 3B, the shape of the first dummy light-transmitting column 108D in the upper view is oval. However, the present invention is not limited to this. In other embodiments, the first dummy light-transmitting column 108D may be a circle, an ellipse, or a rectangle of any size, depending on design and process requirements.

In some embodiments, as shown in FIG. 3B, the width W of the transparent pillar 108 is smaller than the width DW of the first dummy transparent pillar 108D. In this way, the array structure of the light transmission pillars 108 can be further strengthened by the wider first dummy light transmission pillars 108D. However, the present invention is not limited to this. In other embodiments, the width W of the light transmission pillar 108 may be greater than or equal to the width DW of the first dummy light transmission pillar 108D, and the light transmission pillar 108 may still be strengthened at this time. Array structure to prevent deformation of the transparent pillar 108 at the edge of the array Collapse, maintaining the uniformity of the light-transmitting column 108, thereby improving the yield.

In some embodiments, as shown in FIG. 3B, the pitch P of the transparent pillars 108 is equal to the pitch DP of the first dummy transparent pillars 108D. In this way, it is possible to prevent the first dummy light transmitting pillars 108D from being too close to each other to collapse and deform. However, the present invention is not limited to this. In other embodiments, if the process capability permits, the pitch DP of the first dummy translucent pillar 108D may be smaller than the pitch P of the translucent pillar 108. The array structure of the light transmission pillars 108 is further strengthened by the denser first dummy light transmission pillars 108D. Alternatively, in other embodiments, in order to prevent the first dummy transparent light columns 108D from being too close to each other and collapsing and deforming, the pitch DP of the first dummy light transparent columns 108D may be greater than the pitch P of the light transparent columns 108.

In some embodiments, if the area ratio of the light-transmitting pillar 108 and the first dummy light-transmitting pillar 108D is too large, the peripheral elements of the light collimation layer 112 may be affected. If the area ratio of the light-transmitting column 108 and the first dummy light-transmitting column 108D is too small, the area of the fingerprint that can be sensed is too small to effectively sense the fingerprint.

In the above embodiment, the transparent pillar 108 and the first dummy transparent pillar 108D may be formed at the same time by the same process, and the materials of the two are the same. In this way, process time and costs can be saved. However, the present invention is not limited to this. In other embodiments, the materials of the transparent pillar 108 and the first dummy transparent pillar 108D may be different. For example, a light-transmitting pillar 108 may be formed above the pixel 106 and a light-shielding layer 110 is formed therebetween. Then, a patterning process is used to form an opening surrounding the light-transmitting pillar 108 in the light-shielding layer 110 of the first peripheral region 104P, and fill in The light-transmitting material different from the light-transmitting post 108 forms a first dummy light-transmitting post 108D at the opening. Then, a planarization process is performed on the light-transmitting post 108, the first dummy light-transmitting post 108D, and the light-shielding layer 110 by, for example, a chemical mechanical polishing process to remove excess light-transmitting material. With different first dummy transmission The material of the pillar 108D can further strengthen the array structure of the transparent pillars 108, avoid deformation and collapse of the transparent pillars 108 at the edge of the array, and maintain the uniformity of the transparent pillars 108, thereby improving the yield.

As described above, arranging dummy light transmission columns not corresponding to pixels below the light transmission column array of the light collimation layer of the optical sensor can strengthen the light transmission column array structure, avoid deformation and collapse of the light transmission column at the edge of the array, and maintain The uniformity of the light transmission column improves the yield.

FIG. 4 is a top view of the optical sensor 200 according to other embodiments. The processes or components that are the same as or similar to those of the foregoing embodiments will use the same component symbols, and the detailed content will not be described again. The difference from the previous embodiment is that, as shown in FIG. 4, the optical sensor 200 includes a plurality of first dummy light-transmitting columns 208D surrounding the light-transmitting column 108 in the first peripheral region 104P.

In some embodiments, the first dummy transparent pillars 208D in different layers are made of the same material and formed at the same time as the transparent pillars 108. In other embodiments, different layers of the first dummy transparent pillar 208D are made of different materials. After the light-shielding layer 110 is formed by the patterning process, multiple first dummy transmissions of different materials are formed by using multiple patterning processes. Column 208D.

In the embodiment shown in FIG. 4, by forming a plurality of dummy light-transmitting columns, the array structure of the light-transmitting columns can be strengthened, avoiding deformation and collapse of the light-transmitting columns at the edge of the array, and maintaining the uniformity of the light-transmitting columns, thereby improving the quality. rate.

It is worth noting that the number of layers of the dummy light-transmitting columns in FIG. 4 is only an example, and the present invention is not limited thereto. In the embodiment of the present invention, three or more dummy light-transmitting pillar layers may also be included, depending on the manufacturing process and design requirements.

FIG. 5 is a top view of the optical sensor 300 according to other embodiments. Processes or components that are the same as or similar to the previous embodiments will be used Identical component symbols will not be described in detail. The difference from the embodiment shown in FIG. 4 is that, as shown in FIG. 5, the optical sensor 300 includes a plurality of first dummy light-transmitting columns 308D that surround the light-transmitting column 108 in the first peripheral region 104P and are staggered with each other. The “staggered arrangement” here means that the first dummy light-transmitting columns 308D of two adjacent layers are not aligned in the X direction and the Y direction.

In the embodiment shown in FIG. 5, the staggered arrangement of the dummy light-transmitting columns formed by multiple layers can further strengthen the light-transmitting column array structure, avoid deformation and collapse of the light-transmitting columns at the edge of the array, and maintain the uniformity of the light-transmitting columns. Improve yield.

FIG. 6 is a top view of the optical sensor 400 according to other embodiments. The processes or components that are the same as or similar to those of the foregoing embodiments will use the same component symbols, and the detailed content will not be described again. The difference from the previous embodiment is that, as shown in FIG. 6, the optical sensor 400 includes a first dummy light-transmitting column 408D1 surrounding the light-transmitting column 108 in the first peripheral area 404P1, and includes a second peripheral area 404P2 A second dummy transparent pillar 408D2 surrounds the first dummy transparent pillar 408D1. In some embodiments, at least one of the shape, size, pitch, and arrangement of the dummy light-transmitting pillars in different peripheral regions is different. For example, the shape, size, and arrangement of the first dummy transparent pillars 408D1 and the second dummy transparent pillars 408D2 in the first peripheral region 404P1 and the second peripheral region 404P2 are different.

In some embodiments, as shown in FIG. 6, the shape of the first dummy light-transmitting post 408D1 in the top view is circular, and the shape of the second dummy light-transmitting post 408D2 in the top view is oval. However, the present invention is not limited to this. In other embodiments, the first dummy transparent pillar 408D1 and the second dummy transparent pillar 408D2 may be circular, oval, or any size in the top view. rectangle. In some implementations In the example, the shapes of the first dummy transparent pillar 408D1 and the second dummy transparent pillar 408D2 in the top view may be the same. In other embodiments, the first dummy transparent pillar 408D1 and the second dummy transparent pillar 408D1 may have the same shape in the top view. The light beam 408D2 can be different, depending on the design and process requirements.

In some embodiments, as shown in FIG. 6, the width DW1 of the first dummy transparent pillar 408D1 is smaller than the width DW2 of the second dummy transparent pillar 408D2. In this way, the array structure of the light-transmitting pillars 108 can be further strengthened by the wider second dummy light-transmitting pillars 408D2. However, the present invention is not limited to this. In other embodiments, the width DW1 of the first dummy transparent pillar 408D1 may be greater than or equal to the width DW2 of the second dummy transparent pillar 408D2. The light pillar 108 array structure avoids deformation and collapse of the light transmission pillar 108 at the edge of the array, maintains the uniformity of the light transmission pillar 108, and further improves the yield.

In some embodiments, as shown in FIG. 6, the pitch DP1 of the first dummy translucent post 408D1 is equal to the pitch DP2 of the second dummy translucent post 408D2. In this way, it is possible to prevent the second dummy light-transmitting pillars 408D2 from being too close to each other to collapse and deform. However, the present invention is not limited to this. In other embodiments, if the process capability permits, the pitch DP2 of the second dummy light transmission column 408D2 may be smaller than the pitch DP1 of the first dummy light transmission column 108D. As a result, the array structure of the light transmission pillars 108 can be further strengthened by the denser second dummy light transmission pillars 408D2. Alternatively, in order to prevent the second dummy transparent light columns 408D2 from being too close to each other and collapsing and deforming, the pitch DP2 of the second dummy light transparent columns 408D2 may be greater than the pitch DP1 of the first dummy light transparent columns 108D.

In some embodiments, the transparent pillar 108, the first dummy transparent pillar 408D1, and the second dummy transparent pillar 408D2 can be formed at the same time by the same process, and the three materials are the same. In this way, process time and costs can be saved. However, the present invention is not limited to this. In other embodiments, the transparent pillar 108 and the first virtual The materials of the light-transmitting post 408D1 and the second dummy light-transmitting post 408D2 may be different from each other. For example, a light-transmitting pillar 108 may be formed above the pixel 106 and a light-shielding layer 110 is formed therebetween. Then, a patterning process is used to form an opening surrounding the light-transmitting pillar 108 in the light-shielding layer 110 of the first peripheral region 404P1 and fill in The light-transmitting material different from the light-transmitting pillar 108 forms a first dummy light-transmitting pillar 408D1 at the opening. Then, a planarization process is performed on the transparent pillar 108, the first dummy transparent pillar 408D1, and the light-shielding layer 110 by a chemical mechanical polishing process to remove the excess transparent material. Next, a patterning process is used to form an opening surrounding the first dummy transparent pillar 408D1 in the light shielding layer 110 of the second peripheral region 404P2, and fill in a light-transmitting material different from the first dummy transparent pillar 408D1 so that A second dummy light-transmitting post 408D2 is formed at the opening. Then, a planarization process is performed on the transparent pillar 108, the first dummy transparent pillar 408D1, the second dummy transparent pillar 408D2, and the light-shielding layer 110 by using a chemical mechanical polishing process to remove the excess transparent material.

By using different materials for the first dummy transmission pillar 408D1 and the second dummy transmission pillar 408D2, the array structure of the transmission pillar 108 can be strengthened, the deformation and collapse of the transmission pillar 108 at the edge of the array can be avoided, and the uniformity of the transmission pillar 108 can be maintained Degrees, which in turn improves yield.

In some embodiments, the first dummy transparent pillars 408D1 and the second dummy transparent pillars 408D2 may be arranged in a single layer, or may be arranged in multiple layers. In some embodiments, the total number of the first dummy transparent pillars 408D1 and the second dummy transparent pillars 408D2 is between 3 and 5 layers. The first dummy transparent pillars 408D1 and the second dummy transparent pillars 408D2 can be aligned or staggered, depending on the manufacturing process and design requirements.

By forming the same or different shapes, widths, pitches, materials, and arrangement of the first dummy transparent pillar and the second dummy transparent around the array of transparent pillars Columns can further strengthen the structure of the light-transmitting column array, avoid deformation and collapse of the light-transmitting column at the edge of the array, maintain the uniformity of the light-transmitting column, and then improve the yield.

It should be noted that the number of peripheral regions in FIG. 6 is only an example, and the present invention is not limited thereto. For example, as shown in FIG. 7, in another embodiment of the present invention, the optical sensor 500 may include a first peripheral region 404P1, a second peripheral region 404P2, and a third peripheral region 504P3. A dummy transmission pillar 408D1, a second dummy transmission pillar 408D2, and a third dummy transmission pillar 508D3, wherein the first dummy transmission pillar 408D1, the second dummy transmission pillar 408D2, and a third dummy transmission pillar The light-transmitting column 508D3 can be different shapes (for example, circular, oval, or rectangular) or the same shape, depending on the manufacturing process and design requirements.

By forming three or more dummy light-transmitting column layers with the same or different shapes, widths, pitches, materials, layers, and arrangements around the light-transmitting column array, the structure of the light-transmitting column array can be strengthened and the array edge can be avoided. The light beam deforms and collapses, maintaining the uniformity of the light beam, thereby improving the yield.

In summary, an embodiment of the present invention provides an optical sensor. In the light-shielding layer of the light collimation layer, in addition to forming a corresponding array of transparent columns above the pixels, a dummy transparent column is formed to surround the array of transparent columns. . Adjust the geometry, size, arrangement, and material of the dummy light transmission column according to the process requirements. In this way, depending on the process and design requirements, the light transmission column array structure can be strengthened to avoid deformation and collapse of the light transmission column at the edge of the array, maintain the uniformity of the light transmission columns, and improve the yield.

It should be noted that, although the advantages and effects of some embodiments of the present invention have been described above, not all embodiments need to achieve all the advantages and effects.

The foregoing outlines the characteristics of many embodiments, so any Those with ordinary knowledge in the technical field can better understand the aspects of the embodiments of the present invention. Any person with ordinary knowledge in the technical field may design or modify other processes and structures based on the embodiments of the present invention without difficulty to achieve the same purpose and / or obtain the same advantages as the embodiments of the present invention. Any person with ordinary knowledge in the technical field should also understand that different changes, substitutions and modifications can be made without departing from the spirit and scope of the embodiments of the present invention. Such equivalent creations do not exceed the spirit and scope of the embodiments of the present invention.

Claims (19)

An optical sensor includes: a plurality of pixels located in a substrate; a collimating layer on the substrate, including: a light-shielding layer located on the substrate; a plurality of light-transmitting columns; Passing through the light-shielding layer and correspondingly disposed on the pixels; and a plurality of first dummy light-transmitting columns passing through the light-shielding layer and located in a first peripheral area of the light collimation layer; in a top view The first dummy translucent pillars surround the translucent pillars. The optical sensor according to item 1 of the scope of patent application, wherein the first dummy transparent columns do not correspond to any of the pixels. The optical sensor according to item 1 of the scope of patent application, wherein the shapes of the translucent posts in the top view are circular. The optical sensor according to item 1 of the scope of patent application, wherein the shapes of the first dummy light-transmitting columns in the top view are circular, oval, or rectangular. The optical sensor according to item 1 of the scope of the patent application, wherein the widths of the first dummy transparent columns are equal to the widths of the transparent columns. The optical sensor according to item 1 of the scope of the patent application, wherein the widths of the first dummy light transmission columns are not equal to the widths of the light transmission columns. The optical sensor according to item 1 of the scope of patent application, wherein the transparent columns are arranged in an array in the top view. The optical sensor according to item 1 of the patent application scope, wherein the arrangement of the first dummy light-transmitting columns in the upper view is a multilayer arrangement. The optical sensor according to item 8 of the scope of patent application, wherein the first dummy light-transmitting columns are staggered with each other in the top view. The optical sensor according to item 1 of the scope of the patent application, wherein the aspect ratios of the first dummy light transmission columns and the light transmission columns are between 5: 1 and 20: 1. According to the optical sensor described in item 1 of the patent application scope, the light collimation layer further includes: a plurality of second dummy light-transmitting columns, which pass through the light shielding layer and are located in a second peripheral region of the light collimation layer. In which, the second peripheral region surrounds the first peripheral region; and in the upper view, the second dummy transparent pillars surround the first dummy transparent pillars. The optical sensor according to item 11 of the scope of patent application, wherein the widths of the second dummy transparent light columns are not equal to the width of the first dummy transparent light columns. The optical sensor according to item 11 of the scope of patent application, wherein the widths of the second dummy light-transmitting columns are equal to the width of the first dummy light-transmitting columns. The optical sensor according to item 11 of the scope of patent application, wherein the shapes of the second dummy light-transmitting columns in the top view are circular, oval, or rectangular. A method for forming an optical sensor includes: forming a plurality of pixels in a substrate; forming a light collimation layer on the substrate, wherein the forming of the light collimation layer includes forming a plurality of light-transmitting columns and a plurality of First dummy light-transmitting columns are disposed on the substrate, wherein the light-transmitting columns are correspondingly arranged on the pixels, and the first dummy light-transmitting columns are located on a first periphery of the light collimation layer; Area; and forming a light-shielding layer between the light-transmitting columns and the first dummy light-transmitting columns; wherein in a top view, the first dummy light-transmitting columns surround the light-transmitting columns. The method for forming an optical sensor according to item 15 of the scope of the patent application, wherein the first dummy transparent columns do not correspond to any of the pixels. The method for forming an optical sensor according to item 15 of the scope of the patent application, wherein the first dummy light-transmitting columns are arranged in a multi-layer arrangement in the upper view. The method for forming an optical sensor according to item 17 of the scope of the patent application, wherein the first dummy transparent columns are staggered with each other in the upper view. According to the method for forming an optical sensor according to item 15 of the scope of the patent application, the light collimation layer further includes: a plurality of second dummy light-transmitting pillars, which pass through the light shielding layer and are located in a first portion of the light collimation layer Two peripheral regions, wherein the second peripheral region surrounds the first peripheral region; and in the upper view, the second dummy translucent columns surround the first dummy translucent columns.