CN104979370A - Method for forming back-illuminated image sensor with deep trench isolation structure - Google Patents
Method for forming back-illuminated image sensor with deep trench isolation structure Download PDFInfo
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- CN104979370A CN104979370A CN201510425907.7A CN201510425907A CN104979370A CN 104979370 A CN104979370 A CN 104979370A CN 201510425907 A CN201510425907 A CN 201510425907A CN 104979370 A CN104979370 A CN 104979370A
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- trench isolation
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- isolation structure
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Abstract
The present invention provides a method for forming a back-illuminated image sensor with a deep trench isolation structure. The method comprises the steps of S1 providing a device wafer with a first surface and a second surface, and forming a deep trench isolation structure at the first surface of a device wafer, S2 irradiating the surface of the deep trench isolation structure by using laser to raise semiconductor surface temperature so as to repair the damage of the deep trench isolation structure and forming an oxide layer through oxidation under the effect of photoionization and high temperature, wherein the temperature of the first surface is higher than that of the second surface in the laser irradiation process, S3 removing the oxide layer to repair the damage of the deep trench isolation structure. According to the method, laser-assisted oxidation is used, combined with a wet method oxide layer removal process, the lattice damage of the deep trench isolation structure is removed, an image sensor device and metal interconnection are not affected nearly, thus the pixel quality of the image sensor is improved, and thus the carrier migration efficiency is raised, dark current is prevented, and a signal to noise ratio is raised.
Description
Technical field
The present invention relates to field of image sensors, be specifically related to a kind of formation method with the back side illumination image sensor of deep trench isolation structure.
Background technology
Imageing sensor is semiconductor device light signal being converted into the signal of telecommunication, and imageing sensor has photo-electric conversion element.
Imageing sensor is by being divided into again CMOS (Complementary Metal Oxide Semiconductor) (CMOS) imageing sensor and charge-coupled device (CCD) imageing sensor.The advantage of ccd image sensor is to image sensitivity compared with high and noise is little, but ccd image sensor and other devices is integrated more difficult, and the power consumption of ccd image sensor is higher.By contrast, to have technique simple, easily and other devices are integrated, volume is little, lightweight, power consumption is little, low cost and other advantages for cmos image sensor.Therefore, along with technical development, cmos image sensor replaces ccd image sensor more and more and is applied in each electronic product.Current cmos image sensor has been widely used in static digital camera, camera cell phone, Digital Video, medical camera head (such as gastroscope), automobile-used camera head etc.
Existing cmos image sensor is front illuminated (FSI) and back-illuminated type (BSI) respectively, BSI is positioned at the back side into light direction due to multilayers such as metal levels, effectively can prevent the crosstalk (Crosstalk) caused into light, incident flux is provided, has been widely used in middle high pixel image processing sensor field at present; Pixel cell in the array arrangement of pixel region in the process making BSI needs to carry out physical isolation, electric isolation by groove, often adopt in prior art and first do the method that image sensor devices makes deep trench isolation again, this method can cause the defect of deep trench isolation to be difficult to remove, remove according to high temperature thermal oxidation metallization processes, because heating-up temperature is often higher than 800 degrees Celsius, the functional lesion of image sensor devices can be caused, cause imageing sensor to lose efficacy.In addition, improving the transport efficiency of charge carrier in BSI mode, prevent dark current, improving signal to noise ratio is also the problem of extensively seeking in the industry.
Summary of the invention
The object of the present invention is to provide a kind of formation method with the back side illumination image sensor of deep trench isolation structure, be difficult to remove with the defect solving deep trench isolation structure, remove according to high temperature thermal oxidation metallization processes, because heating-up temperature is often higher than 800 degrees Celsius, the functional lesion of image sensor devices can be caused, the problem of effect diagram image-position sensor device quality.
For solving the problem, the invention provides a kind of formation method with the back side illumination image sensor of deep trench isolation structure, comprising the steps:
S1: provide the device wafers with first surface and second surface, forms deep trench isolation structure at the first surface of device wafers;
S2: irradiate deep trench isolation body structure surface by laser and improve semiconductor skin temperature to repair the damage of deep trench isolation structure and be oxidized formation oxide layer under photoionization and high temperature action; In described laser irradiation process, the temperature of first surface is higher than the temperature of second surface;
S3: remove oxide layer to repair the damage of deep trench isolation structure.
Preferably, in described laser irradiation process, the temperature of second surface is lower than 400 degree.
Preferably, step S2 and step S3 is repeated until the damage of deep trench isolation structure is all repaired.
Preferably, the gross thickness removing oxide layer in described step S3 is more than or equal to 20nm.
Preferably, described step S1 also comprises, and before or after formation deep trench isolation structure, forms image sensor devices and metal interconnection at the second surface of device wafers.
Preferably, in described step S2, the wavelength of described laser is 150 nm to 250 nm.
Preferably, in described step S2, the wavelength of described laser is 193 nm or 248 nm.
Preferably, in described step S3, remove oxide layer by buffer oxide or hydrofluoric acid wet etching.
Compared with prior art, technical scheme of the present invention has following advantage:
In technical scheme of the present invention, adopt laser assisted to be oxidized and coordinate wet oxidation layer to remove the lattice damage of technique reparation deep trench isolation structure, image sensor devices and metal interconnection are not almost affected, thus improve the pixel qualities of imageing sensor, and then improve charge carrier transport efficiency, prevent dark current, improve signal to noise ratio.
Accompanying drawing explanation
By Figure of description and subsequently together with Figure of description for illustration of the embodiment of some principle of the present invention, the further feature that the present invention has and advantage will become clear or more specifically be illustrated.Wherein:
Fig. 1 is the flow chart with the formation method of the back side illumination image sensor of deep trench isolation structure of the present invention;
Fig. 2 to Fig. 5 is structural representation corresponding to the part steps with the formation method of the back side illumination image sensor of deep trench isolation structure of the present invention.
Embodiment
The deep trench isolation structure of existing back side illumination image sensor is formed after formation image sensor devices, because Primary Component is formed, in subsequent deep trench recess isolating structure forming process, need temperature, the many factors of environment considers, should ensure that the interface formedness on isolation structure surface prevents damage device again.Owing to can bring blemish in formation isolation structure process, blemish can cause depending on of charge carrier, can increase dark current, and repairing such defect generally needs the multiple particular surroundingss such as high temperature again, can affect and even damage image sensor devices performance.
In technical scheme of the present invention, adopt laser assisted to be oxidized and coordinate wet oxidation layer to remove the lattice damage of technique reparation deep trench isolation structure, image sensor devices and metal interconnection are not almost affected, thus improve the pixel qualities of imageing sensor, and then improve charge carrier transport efficiency, prevent dark current, improve signal to noise ratio.
Below in conjunction with Figure of description, multiple embodiment is adopted to be specifically described this invention.
The invention provides a kind of formation method with the back side illumination image sensor of deep trench isolation structure, as shown in Figure 1, described method comprises the steps:
S1: provide the device wafers with first surface and second surface, forms deep trench isolation structure at the first surface of device wafers;
S2: irradiate deep trench isolation body structure surface by laser and improve semiconductor skin temperature to repair the damage of deep trench isolation structure and be oxidized formation oxide layer under photoionization and high temperature action; In described laser irradiation process, the temperature of first surface is higher than the temperature of second surface;
S3: remove oxide layer to repair the damage of deep trench isolation structure.
Fig. 2 to Fig. 5 is structural representation corresponding to the part steps with the formation method of the back side illumination image sensor of deep trench isolation structure of the present invention.
See Fig. 2, first provide the device wafers 100 with first surface 101 and second surface 102, form deep trench isolation structure 200 at the first surface 101 of device wafers 100.In addition, before or after formation deep trench isolation structure 200, form image sensor devices and metal interconnection (mark) at the second surface 102 of device wafers 100, the structure after completing as shown in Figure 2.
In prior art, usual elder generation is in the second surface 102(front of device wafers 100) form image sensor devices and metal interconnection, and then pass through bonding, thinning, photoetching, the techniques such as etching, the first surface 101(back side in device wafers 100) form deep trench isolation structure 200, manufacturing process can add monocrystalline silicon by simple photoetching and etch, or first deposit hard mask, then by photoetching stiffened mask etching, form hard mask pattern, photoresistance uses hard mask as barrier etch monocrystalline silicon after removing again, all the technique of comparative maturity as mentioned above, do not repeat them here.
See Fig. 3, then irradiate deep trench isolation body structure surface by laser (as shown by the arrows in Figure 3) and improve semiconductor skin temperature, namely high temperature itself have repair to the damage of deep trench isolation structure on the one hand, photoionization and high temperature action provide energy for the surface oxidation of deep trench isolation structure on the other hand, impel it at oxidizing gas (such as O
2+ N
2, or steam+N
2) under environment oxidation form oxide layer 300.
Owing to only making the local temperature near first surface raise in laser irradiation process, by controlling the temperature of second surface lower than the temperature of first surface, can avoid the formation of and suffer damage in the image sensor devices of second surface and metal interconnection.Preferably, the temperature controlling second surface, lower than 400 degree, makes it almost not affect image sensor devices and metal interconnection.Particularly, can by controlling the temperature of the wavelength control second surface of laser.Preferably, the wavelength of described laser is 150 nm to 250 nm.More preferably, the wavelength of described laser is 193 nm or 248 nm.
See Fig. 4, next remove oxide layer 300 by buffer oxide (BOE) or hydrofluoric acid wet etching, thus repair the damage of deep trench isolation structure 200.
As required, can the repeatedly formation of repeated oxidation layer and removal step, that is, this technical process can circulate and carry out, thus farthest removes the lattice defect that deep trench isolation structure-forming process causes, and improves the pixel qualities of imageing sensor.Such as, form the thick oxide layer of about 10nm in the oxidation of deep trench isolation body structure surface and removed in step s3 in step S2, repeat step S2 and step S3 more than twice, the gross thickness of removal oxide layer is made to be more than or equal to 20nm, to ensure that the damage of deep trench isolation structure is all repaired, also should be noted that the residue monocrystalline silicon between the deep trench isolation structure that maintenance is adjacent is abundant, to reduce the loss to full trap electric capacity to greatest extent simultaneously.
See Fig. 5, after the injury repair of deep trench isolation structure 200 completes, proceed follow-up standard BSI technique, such as, form the structure such as filter layer 400, microlens layer 500 successively, finally form the back side illumination image sensor shown in Fig. 5.
In technical scheme of the present invention, adopt laser assisted to be oxidized and coordinate wet oxidation layer to remove the lattice damage of technique reparation deep trench isolation structure, image sensor devices and metal interconnection are not almost affected, thus improve the pixel qualities of imageing sensor, and then improve charge carrier transport efficiency, prevent dark current, improve signal to noise ratio.
Although the present invention discloses as above, the present invention is not defined in this.Any those skilled in the art, without departing from the spirit and scope of the present invention, all can make various changes or modifications, and therefore protection scope of the present invention should be as the criterion with claim limited range.
Claims (8)
1. there is a formation method for the back side illumination image sensor of deep trench isolation structure, it is characterized in that, comprise the steps:
S1: provide the device wafers with first surface and second surface, forms deep trench isolation structure at the first surface of device wafers;
S2: irradiate deep trench isolation body structure surface by laser and improve semiconductor skin temperature to repair the damage of deep trench isolation structure and be oxidized formation oxide layer under photoionization and high temperature action; In described laser irradiation process, the temperature of first surface is higher than the temperature of second surface;
S3: remove oxide layer to repair the damage of deep trench isolation structure.
2. the method for claim 1, is characterized in that, in described laser irradiation process, the temperature of second surface is lower than 400 degree.
3. method as claimed in claim 1 or 2, is characterized in that, repeats step S2 and step S3 until the damage of deep trench isolation structure is all repaired.
4. method as claimed in claim 3, it is characterized in that, the gross thickness removing oxide layer in described step S3 is more than or equal to 20nm.
5. method as claimed in claim 1 or 2, it is characterized in that, described step S1 also comprises, and before or after formation deep trench isolation structure, forms image sensor devices and metal interconnection at the second surface of device wafers.
6. method as claimed in claim 1 or 2, it is characterized in that, in described step S2, the wavelength of described laser is 150 nm to 250 nm.
7. method as claimed in claim 6, it is characterized in that, in described step S2, the wavelength of described laser is 193 nm or 248 nm.
8. method as claimed in claim 1 or 2, is characterized in that, in described step S3, removes oxide layer by buffer oxide or hydrofluoric acid wet etching.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2017173637A1 (en) * | 2016-04-07 | 2017-10-12 | 格科微电子（上海）有限公司 | Method for manufacturing back-illuminated image sensor using back-side deep trench isolation |
| CN111710602A (en) * | 2020-06-10 | 2020-09-25 | 上海华力集成电路制造有限公司 | Manufacturing method of high-K dielectric layer |
| CN116779544A (en) * | 2023-08-23 | 2023-09-19 | 合肥晶合集成电路股份有限公司 | Manufacturing method of semiconductor structure |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101728308A (en) * | 2008-10-24 | 2010-06-09 | 中芯国际集成电路制造(上海)有限公司 | Method for manufacturing shallow trench isolation structure |
| CN102347338A (en) * | 2010-07-27 | 2012-02-08 | 台湾积体电路制造股份有限公司 | A device including a back side illuminated image sensor and a manufacture method of the image sensor |
| CN102412141A (en) * | 2011-11-14 | 2012-04-11 | 上海华虹Nec电子有限公司 | Method for removing oxide film residues in deep groove |
| US20130113061A1 (en) * | 2011-11-07 | 2013-05-09 | Taiwan Semiconductor Manufacturing Company, Ltd. | Image sensor trench isolation with conformal doping |
-
2015
- 2015-07-20 CN CN201510425907.7A patent/CN104979370B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101728308A (en) * | 2008-10-24 | 2010-06-09 | 中芯国际集成电路制造(上海)有限公司 | Method for manufacturing shallow trench isolation structure |
| CN102347338A (en) * | 2010-07-27 | 2012-02-08 | 台湾积体电路制造股份有限公司 | A device including a back side illuminated image sensor and a manufacture method of the image sensor |
| US20130113061A1 (en) * | 2011-11-07 | 2013-05-09 | Taiwan Semiconductor Manufacturing Company, Ltd. | Image sensor trench isolation with conformal doping |
| CN102412141A (en) * | 2011-11-14 | 2012-04-11 | 上海华虹Nec电子有限公司 | Method for removing oxide film residues in deep groove |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2017173637A1 (en) * | 2016-04-07 | 2017-10-12 | 格科微电子（上海）有限公司 | Method for manufacturing back-illuminated image sensor using back-side deep trench isolation |
| CN111710602A (en) * | 2020-06-10 | 2020-09-25 | 上海华力集成电路制造有限公司 | Manufacturing method of high-K dielectric layer |
| CN116779544A (en) * | 2023-08-23 | 2023-09-19 | 合肥晶合集成电路股份有限公司 | Manufacturing method of semiconductor structure |
| CN116779544B (en) * | 2023-08-23 | 2023-11-28 | 合肥晶合集成电路股份有限公司 | Manufacturing method of semiconductor structure |
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