阅读说明：本技术 一种光学镀膜半导体晶圆嫁接方法及光学镀膜半导体 (Optical coated semiconductor wafer grafting method and optical coated semiconductor ) 是由 葛文志 翁钦盛 王刚 陈银培 丁宇能 周洋 陈博 于 2021-07-26 设计创作，主要内容包括：本发明提供一种光学镀膜半导体晶圆嫁接方法及光学镀膜半导体,该方法通过将光刻胶涂布在半导体晶圆基板表面并在半导体晶圆基板的表面划分为透光区和遮光区,让然后采用光刻工艺在所述透光区刻画图案再进行光学薄膜的沉积,将高折射率或低折射率材料的光学薄膜膜层交错堆叠在所述透光区表面,使得所述透光区和所述遮光区交界处膜层厚度梯度变化,最后去除所述光刻胶即可。该方法获得的光学镀膜半导体在竖直方向上,IRC层的远离基板的边缘与涂胶背胶面的边缘不重叠,在保证其正常的电性能的前提下附加光学性能,附加的光学性能使产品精度大大提高,具有很高的推广价值。(The invention provides an optical coated semiconductor wafer grafting method and an optical coated semiconductor, wherein photoresist is coated on the surface of a semiconductor wafer substrate and is divided into a light transmitting area and a light shielding area on the surface of the semiconductor wafer substrate, then a photoetching process is adopted to draw patterns on the light transmitting area, then deposition of an optical film is carried out, optical film layers made of materials with high refractive index or low refractive index are stacked on the surface of the light transmitting area in a staggered mode, the thickness gradient of the film layer at the junction of the light transmitting area and the light shielding area is changed, and finally the photoresist is removed. The optical coated semiconductor obtained by the method has the advantages that in the vertical direction, the edge of the IRC layer far away from the substrate is not overlapped with the edge of the gluing back glue surface, the optical performance is added on the premise of ensuring the normal electrical performance of the optical coated semiconductor, the product precision is greatly improved due to the additional optical performance, and the popularization value is very high.)

1. An optical coating semiconductor wafer grafting method is characterized in that: comprises the steps of (a) preparing a mixture of a plurality of raw materials,

(1) coating photoresist on the surface of a semiconductor wafer substrate;

(2) dividing the surface of the semiconductor wafer substrate into a light-transmitting area and a light-shielding area;

(3) protecting the shading area by using photoresist, and etching a pattern on the light-transmitting area by adopting a photoetching process;

(4) depositing an optical film after the photoetching process is finished, and alternately stacking optical film layers made of materials with high refractive index or low refractive index on the surface of the light transmitting area, wherein the thickness gradient of the film layer at the junction of the light transmitting area and the shading area is changed;

(5) and removing the photoresist.

2. The method for grafting an optically coated semiconductor wafer according to claim 1, wherein: the film thickness gradient of the 1.5-3.5um range area of the junction of the light-transmitting area and the light-shading area changes.

3. The method for grafting an optically coated semiconductor wafer according to claim 1, wherein: in the step (4), the first optical film layer stacked on the surface of the light-transmitting area is a low-refractive-index film layer, and the second optical film layer is a high-refractive-index film layer.

4. The method for grafting an optically coated semiconductor wafer according to claim 1, wherein: in the step (4), the first optical film layer stacked on the surface of the light-transmitting area is a high refractive index film layer, and the second optical film layer is a low refractive index film layer.

5. The method for grafting an optically coated semiconductor wafer according to claim 3 or 4, wherein: the refractive index of the low refractive index film layer is 1.4-1.55, and the refractive index of the high refractive index film layer is 2-4.5.

6. The method for grafting an optically coated semiconductor wafer according to claim 1, wherein: in the step (4), the total number of stacked layers is 2-60.

7. The method for grafting an optically coated semiconductor wafer according to claim 1, wherein: in the step (3), the pattern is square.

8. The method for grafting an optically coated semiconductor wafer according to claim 1, wherein: in the step (4), the outermost surface of the optical film is silicon dioxide.

9. Optically coated semiconductor obtainable by the process according to any of claims 1 to 8, characterized in that: in the vertical direction, the edge of the IRC layer far away from the substrate is not overlapped with the edge of the gluing back glue surface.

Technical Field

The invention relates to the field of semiconductor wafer chips, in particular to an optical film-coated semiconductor wafer grafting method and an optical film-coated semiconductor.

Background

Most electronic products on the market currently use semiconductor chips made of single crystal silicon, and the main manufacturing method is to etch and wire on a semiconductor wafer sheet to form a semiconductor wafer device capable of realizing a certain function. As a new industry, a biometric device is rapidly developing, and a chip used in the biometric device is a semiconductor chip, and the semiconductor chip realizes biometric identification by using its own electrical property.

Disclosure of Invention

In order to solve the technical problems, the invention designs an optical film-coated semiconductor wafer grafting method and an optical film-coated semiconductor. The development is based on the background that the optical film is combined with the semiconductor wafer by utilizing the photoetching process, the optical film is deposited on the original semiconductor wafer, and the optical performance is added on the premise of ensuring the normal electrical performance of the optical film, so that the aim of improving the product precision is fulfilled.

The invention adopts the following technical scheme: a method for grafting an optical coating semiconductor wafer comprises (1) coating photoresist on the surface of a semiconductor wafer substrate; (2) dividing the surface of the semiconductor wafer substrate into a light-transmitting area and a light-shielding area; (3) protecting the shading area by using photoresist, and etching a pattern on the light-transmitting area by adopting a photoetching process; (4) depositing an optical film after the photoetching process is finished, and alternately stacking optical film layers made of materials with high refractive index or low refractive index on the surface of the light transmitting area, wherein the light transmitting area and the shading area; the thickness gradient of the film layer at the junction is changed; (5) and removing the photoresist.

Preferably, the interface between the light-transmitting area and the light-shading area is in a range of 1.5-3.5um, and the thickness of the film layer is in gradient change.

Preferably, in the step (4), the first optical film layer stacked on the surface of the light-transmitting area is a low refractive index film layer, and the second optical film layer is a high refractive index film layer.

Preferably, in the step (4), the first optical film layer stacked on the surface of the light-transmitting area is a high refractive index film layer, and the second optical film layer is a low refractive index film layer.

Preferably, the refractive index of the low refractive index film layer is 1.4-1.55, and the refractive index of the high refractive index film layer is 2-4.5.

Preferably, in step (4), the total number of layers of the stack is 2 to 60.

Preferably, in step (3), the pattern is square.

Preferably, in the step (4), the outermost surface of the optical film is silica.

As another aspect of the present invention, there is provided an optically coated semiconductor characterized in that: in the vertical direction, the edge of the IRC layer far away from the substrate is not overlapped with the edge of the gluing back glue surface.

The invention has the beneficial effects that:

the optical film is deposited on the semiconductor wafer element, the optical performance is added on the premise of ensuring the normal electrical performance of the semiconductor wafer element, and the product precision is greatly improved due to the additional optical performance;

compared with the traditional coating mode production process, the invention also has the following advantages:

1. number advantage: the production process of the traditional coating mode can only be used for one piece at a time, the mode of the invention can increase the yield, and the coating equipment is different and has different quantity according to the size, for example, 12 pieces of 12 inch products can be coated at one time;

2. the thickness uniformity advantage is as follows: the prior coating method is not uniform enough, the range is 80nm, the uniformity is not good, and the change of the spectral waveform influences the transmittance of the product. By adopting the method of the invention, the film layer can be more uniform, and the range of the range can be controlled within 5 nm.

3. The efficiency advantage is as follows: the coating characteristic can not be changed at will due to the ink characteristic, and the coating curve of the invention can be changed in time according to the customer requirement, so that the time arrangement efficiency is higher.

Drawings

FIG. 1 is a schematic view of a film layer structure of a processed product of the process of the present invention;

FIG. 2 is a schematic illustration of mass production of the product processed by the process of the present invention;

FIG. 3 is a microscopic scan of the optical film layer of the processed product of the process of the present invention;

FIG. 4 is a test reliability chart of sample number 2 of the processed product of the process of the present invention and a film thickness measurement chart above its IRC;

FIG. 5 is a data drop detection plot of an optical film layer of a processed product of the process of the present invention;

Detailed Description

The technical scheme of the invention is further described in detail by the following specific embodiments in combination with the attached drawings:

the operation device of the present invention: photoetching machine, film coating machine, exposure machine and developing machine.

The finished product detection method comprises the following steps: the high-temperature storage detection experiment needs to be stored for 1000 hours at 125 ℃, and observation is carried out every 500 hours; the low-temperature storage detection experiment needs to be stored for 500 hours at the temperature of minus 40 ℃, and observation is carried out every 250 hours; the constant temperature and humidity detection experiment needs to be stored for 1000 hours at 85 ℃/85% RH and observed every 500 hours; the temperature impact detection experiment needs to carry out cyclic impact at the temperature of-40-85 ℃, one cycle is carried out every 30min, 1000 cycles need to be completed, and observation is carried out every 500 cycles; the PCT detection experiment needs to be kept still for 18h at the temperature of 121 ℃, the humidity of 100 percent RH and the pressure of 2 Mpa.

Example 1

As shown in the attached figure 1, a technique for grafting an optical coated semiconductor wafer comprises the following steps:

1. selecting a 12-inch silicon semiconductor wafer;

2. dividing the surface of the semiconductor wafer substrate into a light-transmitting area and a light-shielding area;

3. the photoresist is uniformly coated on the shading area on the surface of the semiconductor wafer by using a spin coating process, the shading area which does not need to be combined with an optical film is protected, an inverted trapezoid or a regular trapezoid can be formed at the junction of the shading area and the light transmission area during gluing, and the light transmission area and the shading area can be accurately distinguished through gluing and developing of a photoetching machine in the subsequent process. Research shows that the steeper the inclined side of the inverted trapezoid or the regular trapezoid formed at the junction of the shading area and the light transmission area is, the better the inclined side of the trapezoid is, and if the gradient of the trapezoid is too small (if the ratio of the height of the slope to the width of the slope is less than 1: 1.5, the slope is too small), data falling in the area can be caused, and the recognition effect is affected.

4. Making corresponding patterns on the light-transmitting area on the surface of the substrate of the semiconductor wafer by utilizing a photoetching process, wherein the patterns are regular in shape and preferably square, and as can be seen in FIG. 2, the size precision of the patterns of the optical thin film layer reaches 0.3 um;

5. after the photoetching process is finished, depositing an optical film by adopting an evaporation process, and alternately stacking optical film layers made of materials with high refractive index and low refractive index on the surface of the unprotected light-transmitting area of the semiconductor wafer to be firmly combined with the semiconductor wafer; the refractive index of the film layer of the low refractive index material is 1.4-1.55, the refractive index of the film layer of the high refractive index material is 2-4.5, and the total number of the deposited film layers of the optical film is 2-60.

For convenience of description, after depositing the optical film on the semiconductor wafer substrate, the contact surface of the first layer film and the semiconductor wafer substrate is referred to as a glue-coated back surface.

6. And removing the photoresist in the shading area by using an etching process to obtain a finished product, and completing the grafting of the whole optical coating semiconductor wafer according to the uppermost graph in the graph of fig. 3.

In step 5, a first optical film layer made of a low refractive index material and a second optical film layer made of a high refractive index material are stacked on the surface of the light-transmitting area of the semiconductor wafer in a staggered manner, and the deposited optical films are arranged to reach the condition that visible light penetrates through redThe effect of external light cut-off; in step 5, a layer of silica is attached to the outermost surface of the optical film. The film layer of low and high refractive index material may be Ti₃O₅-SiO₂、Nb₂O₅、Ta₂O₅、TiO₂、ZrO₂、HfO₂、Ti₃O₅-SiO₂、Nb₂O₅、Ta₂O₅。

Taking a square row as an example, the finished product is prepared by utilizing the steps according to the following film layer scheme, and the method comprises the following specific steps:

and after the finished product is obtained, sequentially carrying out high-temperature storage, low-temperature storage, constant temperature and humidity, temperature impact and PCT detection experiments on the finished product, observing whether the finished product is subjected to demoulding and film cracking, and judging to obtain a final qualified finished product. The test shows that the surface of a sample after the test has dirt and is not easy to wipe (see figure 4), the test piece is taken out of the slice to measure the film thickness of the dirt position and the non-dirt position, the dirt is only attached in the process of reliability, the film thickness of the product does not change, and the abnormalities such as falling, cracking, layering, foaming and the like do not occur, and the rest tests also result that the sample does not have the abnormalities such as falling, cracking, layering, foaming and the like.

The application discovers that the L-shaped edge data falling condition exists between the gluing back glue surface and the first film layer (such as an IRC layer) in the research process, and the larger gradient of the inverted trapezoid or the regular trapezoid formed during gluing is the reason for the data falling in the area. Through detection, the ratio of the height of the trapezoid formed by gluing to the width of the sample with the sequence number 1 and the sample with the sequence number 2 is respectively as follows: 1.45: 1.65 and 1.5: 1.55, approximately 1: 1, the better glue shape is maintained, the data drop condition basically does not occur, but only when the edge of the IRC layer far away from the substrate in the vertical direction is overlapped with the edge of the gluing back glue surface, serious edge drop occurs, and the product detection is abnormal (see figure 5).

The above-described embodiments are only preferred embodiments of the present invention, and are not intended to limit the present invention in any way, and other variations and modifications may be made without departing from the spirit of the invention as set forth in the claims.