JP2000321794A - Method for removing photoresist material in original position - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to remove a photoresist material in an original position by etching a target by use of a pattern on the photoresist material on an etching machine, removing part of the photoresist by use of a plasma and removing the entire photoresist by use of a solvent. SOLUTION: The step of patterning and forming a complementary type metal oxidized film semiconductor (CMOS) photosensor 10 and the stage of removing a completely dried photoresist layer 24 are executed on the same etching so as to eliminate the need for transferring the CMOS photosensor 10 onto another etching machine. The production time for forming the CMOS photosensor 10 is thereby saved. Further, the external influences from the environment decrease. The oxygen plasma in the original position is given in order to remove the portion of the dried photoresist layer 24 during executing the pattern forming step. The solvent is thereafter used in order to effectively removing another photoresist layer 24 on the polyacrylate layer of the CMOS photosensor 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates generally to a process for removing photoresist material, and more particularly to a process for removing photoresist material in the manufacture of CMOS (Complementary Metal Oxide Semiconductor) photosensors.

[0002]

2. Description of the Related Art Conventionally, charge-coupled devices have been used in digital sensors. However, due to the size and cost of charge coupled devices, CMOS photosensors have recently been developed. The CMOS light sensor is electrically connected to another element or another CMOS light sensor. To prevent the light sensitive area of the substrate from making electrical contact with the overlying contact pads, a cover layer is used to protect and isolate. In such a case, the cover layer includes a colored filter layer for filtering light of a certain wavelength, and a protective layer for an acrylic material layer or a colored filter layer as a planarizing layer.

[0003]

In conventional semiconductor fabrication, silicon glass or silicon nitride is placed under a photoresist material. Plasma enhanced method (plas
While removing the photoresist material using the ma enhanced method, silicon glass and silicon nitride do not chemically react with oxygen if the plasma contains oxygen. However, since the properties of the acrylic material are similar to those of the photoresist material, it is difficult to remove the photoresist material by plasma without damaging the acrylic material layer after making a hole on the metal pad by photolithography. Therefore, it is proposed that the photoresist material be removed using a solvent.

Since the properties of the photoresist material change after ion bombardment of the plasma in the etching process, the photoresist material easily remains when the plasma is not used. The surface of the photoresist material is dry. Therefore, the photoresist material cannot be sufficiently removed by the solvent. For example, after an etching process to pattern a passivation layer of a CMOS photosensor, the CMOS photosensor may
r) Removed by the etching machine. Dry photoresist material is removed by oxygen plasma in an asher etcher. The remaining photoresist material is
It is removed using a solvent.

However, the asher etcher cannot finely control a stable etching rate while etching a dry photoresist material. The etching temperature increases with the etching time so that the etching rate increases. Therefore, over-etching easily occurs and the acrylic material layer is damaged. Therefore,
It is difficult to control the etching time. Due to residual photoresist material and acrylic material layer damage, the cover layer
A flat form cannot be maintained. In such a case, light transmitted through the light sensor is obstructed, and the light sensitivity of the light sensor is reduced. Therefore, CMOS
It is desirable to completely remove the photoresist material on the cover layer during the manufacture of an optical sensor, especially during industrial scale manufacturing.

[0006]

SUMMARY OF THE INVENTION The present invention provides an in-situ (in-s
itu) to remove the photoresist material.
An etching process is performed on the etching machine to pattern the passivation of the CMOS optical sensor. In situ oxygen is used to remove the dry photoresist material. For example, etching machine
On Tegal-903, an etching process and an in-situ O ₂ process are performed. Tegal-903 is used to remove dry photoresist material using oxygen plasma.
Is more stable than an asher etching machine. A stable etch rate is thus obtained to prevent the acrylic material layer from being over-etched and damaged, and from remaining photoresist material.

Further, the steps of patterning the CMOS photosensor and removing the dry photoresist material are performed on the same etcher so that the CMOS photosensor does not need to be transferred to another etcher. Will be The manufacturing time to form a CMOS photosensor is:
This saves money. In addition, external influences from the environment are reduced.

The present invention performs the step of patterning a passivation layer of a CMOS photosensor using an etching machine Tegal-903. During the patterning step, an in situ oxygen plasma is applied to remove portions of the dried photoresist material. Thereafter, a solvent is used to effectively remove other photoresist material on the polyacrylate layer of the CMOS photosensor. In the manufacture of a typical semiconductor device, an in-situ oxygen plasma step is also used to remove dry photoresist material. Prior to using a solvent to remove the photoresist material, a plasma enhanced etch is used to remove the photoresist.
An in situ oxygen plasma step is used to replace the step of ced etching.

[0009]

Other objects, features and advantages of the present invention will become apparent from the following detailed description of non-limiting embodiments. The description is made with reference to the accompanying drawings. FIG. 1 is a cross-sectional view illustrating a structure of a CMOS photosensor including a photoresist material on which a passivation layer of the CMOS photosensor is patterned. CMOS photosensors are used for other devices and other CMOS
It is electrically connected to the S light sensor. A cover layer is used to protect and isolate the light sensitive area of the substrate to prevent electrical contacts from overlying contact pads.
In such a case, the cover layer comprises a colored filter layer for filtering light of a certain wavelength and an acrylic material layer as a flattening layer or a protective layer for the colored filter layer.

FIG. 1 is a cross-sectional view illustrating the structure of a CMOS photosensor that includes a photoresist material thereon for patterning a passivation layer of the CMOS photosensor. In FIG. 1, reference numeral 10 denotes a part of the structure of the CMOS photosensor located below the sensor region 12 and the pad 14. The first protective layer 16, the filter layer 18, and the second
Cover layer 22 including protective layer 25 of sensor region 1
2 and pad 14. The material of the cover layer 22 should be light transmissive. The material of the cover layer 22 is preferably an acrylic material. Filter layer 1
Material 8 is adjusted to filter light of a certain wavelength.

In order to connect to an external device, the pad 14
The portion of the cover layer 22 located above must be removed. A photoresist layer 24 is provided to clearly define the cover layer 22. After the cover layer 22 has been defined, the pad 1
An etching process is performed to remove the cover layer 22 on the upper side of FIG. The etching process is an etching machine Tegal-90
Desirably done on 3. After performing an etching process for removing a part of the cover layer 22, the photoresist layer 24 is removed.

Since the surface of the photoresist layer 24 is damaged during the etching process and dries, the photoresist layer 24 cannot be easily removed using a solvent. Further, if a plasma is used to enhance the solvent's ability to remove the photoresist layer 24,
The cover layer 22 remaining under the photoresist layer 24 can be damaged. The present invention removes the dry photoresist layer 24 on the same etcher, for example, the etcher Tegal-903. This means
This means that the etching process and the step of removing the dried photoresist layer 24 are performed on the same etching machine. The dried photoresist layer 24 is removed using a plasma containing oxygen.

As the plasma, oxygen plasma is desirable. The parameters when using plasma are about 1500
-2000 mtorr, preferably about 1800 mtorr
r, a speed of 4-16 cm ³ / min (sccm), preferably about 8 cm ³ / min (sccm), and a pressure of about 200-
500 watts, and preferably about 300 watts of power. The step of using the plasma is performed for about 30 seconds. Further, the temperature of the top electrode used to form the plasma may be about 22-28 degrees Celsius, preferably about 2 degrees Celsius.
5 degrees. The temperature of the lower electrode used to form the plasma is about 17-23 degrees Celsius, preferably about 20 degrees Celsius.
Degrees. A solvent is used to remove the residual photoresist layer 24. Since the dried photoresist layer is removed, the remaining photoresist layer is easily removed.

The etching machine Tegal-903 has excellent control of the removal processing. Using the Tegal-903 etcher to remove the dry photoresist layer prevents damage to the cover layer below the photoresist layer and avoids leaving part of the photoresist layer above the cover layer And obtains a stable etching rate. Further, the etching process and the step of removing the dried photoresist layer are performed on the same etcher, saving the time required to manufacture CMOS photoresist.

However, in a typical etching process for manufacturing a semiconductor device, a material under a photoresist layer and a photoresist material has a wide selection range of etching. During the removal of the photoresist layer with the solvent, the step of using plasma to enhance the etching power of the solvent is performed for a long time. The plasma can damage pads of the semiconductor device. The method of the present invention can also be used to remove photoresist material in normal etching processes when fabricating semiconductor devices to further save cycle time and prevent damage to the pads.

Although the present invention has been described by way of example and embodiments, it should be understood that the invention is not limited thereto. On the contrary, the solutions and procedures similar to those of the various modifications and the scope of the appended claims should be adapted to a broad interpretation so as to encompass all of them. is there.

[Brief description of the drawings]

FIG. 1 shows a C containing a photoresist material thereon for patterning a passivation layer of a CMOS photosensor.
It is sectional drawing which shows the structure of a MOS photosensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 12 ... Sensor area 14 ... Pad 16 ... 1st protective layer 18 ... Filter layer 22 ... Cover layer 24 ... Photoresist layer 25 ... 2nd protective layer

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H096 AA25 CA05 HA23 HA25 LA07 LA09 5F046 LB01

Claims (17)

[Claims] 1. A method of removing photoresist material in situ, wherein the photoresist material is provided on a target layer, the photoresist material is exposed and developed, and on an etching machine, Using a pattern on the photoresist material to etch the target; removing the portion of the photoresist using plasma on an etcher; and using a solvent to remove all other photoresist materials. Removing. 2. The method according to claim 1, wherein said etching machine comprises Tegal-903. 3. The method of claim 1, wherein said target material comprises an acrylic material. 4. The method according to claim 1, wherein said plasma includes oxygen. 5. The plasma of claim 1, wherein said plasma is about 1500-2000.
mtorr pressure, the desired pressure is about 1
5. The method of claim 4, wherein the speed is 800 mtorr. 6. The method of claim 4, wherein said oxygen has a rate of about 4-16 sccm, preferably at a rate of about 8 sccm. 7. The method of claim 4, wherein said plasma is used at a power of about 200-500 watts, and preferably at a power of about 300 watts. 8. The upper electrode used to form the plasma is about 22-28 degrees Celsius, preferably about 25 degrees Celsius, and the lower electrode used to form the plasma is 5. The method of claim 4, wherein the temperature is about 17-23 degrees, preferably about 20 degrees Celsius. 9. The method of claim 4, wherein said plasma is used for about 30 seconds. 10. A method for removing photoresist material from an in-situ CMOS photosensor, comprising:
The passivation layer of the optical sensor is located under the photoresist material, and on an etching machine, a step of etching a target using a pattern on the photoresist material, and a plasma containing oxygen is etched on the etching machine. Using a solvent to remove a portion of the photoresist; and using a solvent to remove all other photoresist material. 11. The method of claim 10, wherein said etching machine comprises Tegal-903. 12. The method of claim 10, wherein the material of the passivation layer comprises an acrylic material.
The described method. 13. The plasma of claim 1, wherein said plasma is about 1500-200.
11. The method of claim 10 wherein the pressure is 0 mtorr and the desired pressure is about 1800 mtorr.
The described method. 14. The method of claim 10, wherein said oxygen has a rate of about 4-16 sccm, preferably at a rate of about 8 sccm. 15. The method of claim 10, wherein said plasma is used at a power of about 200-500 watts, and preferably at a power of about 300 watts. 16. The method according to claim 1, wherein the upper electrode used to form the plasma is about 22-28 degrees Celsius, preferably about 25 degrees Celsius, and the lower electrode used to form the plasma is The method of claim 10, wherein the temperature is about 17-23 degrees, preferably about 20 degrees Celsius. 17. The method of claim 10, wherein said plasma is used for about 30 seconds.