CN105448652B

CN105448652B - The cleaning procedure of contact groove and the forming method of contact layer

Info

Publication number: CN105448652B
Application number: CN201410415548.2A
Authority: CN
Inventors: 张琴; 林艺辉; 刘焕新
Original assignee: Semiconductor Manufacturing International Shanghai Corp
Current assignee: Semiconductor Manufacturing International Shanghai Corp
Priority date: 2014-08-21
Filing date: 2014-08-21
Publication date: 2018-05-04
Anticipated expiration: 2034-08-21
Also published as: CN105448652A

Abstract

This application provides a kind of cleaning procedure of contact groove and the forming method of contact layer.The cleaning procedure of contact groove includes the following steps：Step S1：The lower surface of the contact groove is cleaned using SC1 cleaning solutions, removes the particle of the lower surface；Step S2：After the step S1, the lower surface is cleaned using ozonated deionized water, the lower surface is aoxidized and forming oxide in the lower surface makes the lower surface smooth-out；Step S3：After the step S2, the lower surface is cleaned using the pre- clear techniques of SiCoNi, removes the oxide formed in the step S2.Exposure level between metal silicide and silicon face between the metal closures and silicon face of the application raising contact layer, so as to reduce contact resistance, improves the electric property of semiconductor components and devices.

Description

The cleaning procedure of contact groove and the forming method of contact layer

Technical field

This application involves technical field of manufacturing semiconductors, cleaning procedure and contact more particularly, to a kind of contact groove The forming method of layer.

Background technology

In integrated circuit fabrication, it is often necessary to set between the metal closures and silicon face of contact layer (contact, CT) Metal silicide is to increase electric conductivity.If metal silicide is formed at before contact layer, for first metal silicide technology (silicide-first prosess)；If metal silicide is formed at after contact layer, for rear metal silicide technology (silicide-last prosess)。

In the prior art, the pre- clear techniques of SiCoNi are typically used in first metal silicide technology to metal silicide surface Cleaned.But in rear metal silicide technology, since the silicon face for being used to be formed metal silicide after etching is unclear It is clean and rough, it is not enough to be surface-treated the silicon face for forming metal silicide using the pre- clear techniques of SiCoNi.

Fig. 1 is that the silicon face for forming metal silicide is carried out using the pre- clear techniques of SiCoNi in rear metal silicide technology After surface treatment, the metal silicide and the corresponding active area and the scanning electron microscope (SEM) photograph of contact layer that are formed.As shown in Figure 1, its In, metal silicide 20 ' (such as NiPtSi metal silicides) is arranged at the silicon face of active area 10 ' and the metal closures of contact layer Between 30 ', still, due to carrying out surface to silicon face only with the pre- clear techniques of SiCoNi before metal silicide 20 ' is formed Processing, therefore, rough and uneven in surface between the silicon face of active area 10 ', this causes connecing for metal silicide 20 ' and active area 10 ' Resistance of getting an electric shock increases, so as to have a negative impact to the electric property of semiconductor components and devices.

In addition, with CMOS (Complementary Metal Oxide Semi-conductor, complementary metal oxide Thing semiconductor) characteristic size reach 20nm and following, grid technique (High k Metal Gate last) quilt after high-k/metal gate Promote and apply, but need annealing after high K medium material deposition to improve the quality of high K medium material.During annealing High temperature NiPtSi metal silicides can be had an impact, therefore, in order to avoid this influence, in the metal closures and silicon of contact layer Metal silicide between surface need to be formed after metal gate is formed, and while forming the metal silicide need to deposit NiPt or W In in the contact groove of ILD (interlayer dielectric, inter-level dielectric).

Under normal circumstances, in the formation process of NiPtSi metal silicides, inter-level dielectric CMP (Chemical are passed through Mechanical Polishing, chemically mechanical polishing), photoresist covering, etching inter-level dielectric and etc. define contact groove after, Contact groove need to be cleaned, form NiPtSi metal silicides after cleaning in the lower surface of contact groove again.The prior art In, the cleaning procedure used during contact groove is cleaned first to be cleaned with DHF cleaning procedures to contact groove, then it is pre- clear with SiCoNi Technique cleans contact groove.

Fig. 2A to Fig. 2 C is the structure diagram for the main flow node that contact layer is formed in the rear grid technique of the prior art. Wherein, Fig. 2A is to be contacted in the rear grid technique of the prior art in layer formation process, the structure diagram that contact trench etch finishes；Figure 2B is in the rear grid technique of the prior art, contacts the structure diagram after contact groove cleaning in layer formation process；Fig. 2 C are In the rear grid technique of the prior art, contact and metal silicide (such as NiPtSi) and deposited metal plug material are formed in layer formation process Structure diagram after (such as tungsten).

In Fig. 2A to Fig. 2 C, each label represents respectively：1 is silicon substrate, and 2 be STI (Shallow Trench Isolation, shallow trench isolation), 3 be doped region (such as N+ areas or P+ areas), and 4 be high-K metal gate, and 5 be SiN layer, and 6 be ILD layer (such as PEOX, plasma heavier-duty Si oxide), 7 be coarse silicon face, and 8 be smooth silicon face, and 9 be metal silicide, 11 It is contact groove for the metal closures of contact layer, 19.

Shown in Fig. 2A to Fig. 2 C in the prior art, due to using DHF cleaning procedures pair before the pre- clear techniques of SiCoNi Contact groove is cleaned, and DHF cleanings use HF solution as cleaning solution, and HF is to forming the oxide of ILD with higher Rate of etch, not only the lower surface of contact groove is cleaned, also at the same time by the ILD oxides at the lateral and top of contact groove Part removes, this becomes larger the critical size for the metal closures for causing contact layer, also causes the metal closures of contact layer to shorten.So that The electric property for obtaining semiconductor components and devices is deteriorated, for the semiconductor components and devices that line width is below 20nm, in some instances it may even be possible to tight Arrive again and cause short circuit between adjacent electrode.

The content of the invention

The application purpose is to provide a kind of cleaning procedure of contact groove and the forming method of contact layer, it is intended to which raising is partly led The electric property of volume elements device.

The application first aspect provides a kind of cleaning procedure of contact groove, and the cleaning procedure includes the following steps：Step S1：The lower surface of the contact groove is cleaned using SC1 cleaning solutions, removes the particle of the lower surface；Step S2：Described After step S1, the lower surface is cleaned using ozonated deionized water, aoxidizes the lower surface and in the lower surface Forming oxide makes the lower surface smooth-out；Step S3：After the step S2, using the pre- clear technique cleanings of SiCoNi The lower surface, removes the oxide formed in the step S2.

Further, in the step S1, the volume ratio of each component is NH4OH in the SC1 cleaning solutions：H2O2：H2O =1：1~4：50~200.

Further, in the step S1, the cleaning temperature that uses is 23 DEG C to 25 DEG C of room temperature.

Further, in the step S1, cleaning duration is 30s to 120s.

Further, in the step S2, O in the ozonated deionized water₃Concentration be 10ppm to 80ppm.

Further, in the step S2, the cleaning temperature that uses is 23 DEG C to 25 DEG C of room temperature.

Further, in the step S2, cleaning duration is 30s to 120s.

Further, in the step S3, the removal quantity of the oxide is

The application second aspect provides a kind of forming method of contact layer, and the forming method includes the following steps：Step S20：Inter-level dielectric is performed etching to form contact groove；Step S40：After the step S20, using according to the application first The cleaning procedure of contact groove any one of aspect cleans the lower surface of the contact groove；Step S60：Described After step S40, the first metal is deposited in the lower surface of the contact groove and forms metal silicide；Step S80：Described After step S60, the second metal is deposited in the contact groove to form contact layer.

Further, the step S60 includes：Sub-step S62：Described is deposited in the lower surface of the contact groove One metal；Sub-step S64：Thermal annealing is carried out, forms metal silicide；Sub-step S66：Remove unreacted first gold medal Belong to.

Further, first metal is NiPt or W.

Further, first metal deposited in the sub-step S62 is NiPt；The sub-step S64 includes：Point Step S641, carries out a thermal annealing to generate Ni2PtSi；S643 step by step, second heat is carried out after the S641 step by step Anneal to generate NiPtSi metal silicides；The sub-step S66 is between the S641 step by step and the S643 step by step Carry out.

Further, a thermal annealing is low temperature thermal annealing, and the temperature of low temperature thermal annealing is 230 DEG C to 300 DEG C, is moved back The fiery time is 20s to 40s；The second heat is annealed into high-temperature thermal annealing, and the temperature of high-temperature thermal annealing is 450 DEG C to 600 DEG C, is moved back The fiery time is 20s to 40s, or the secondary thermal annealing uses laser annealing, and the temperature of laser annealing is 800 DEG C to 900 DEG C.

Further, in the sub-step S66, first metal is carried out using the mixture of sulfuric acid and hydrogen peroxide wet Method is peeled off.

According to the forming method of the cleaning procedure of the contact groove of the application and contact layer, due to being cleaned using SC1 cleaning solutions The lower surface of contact groove, removes the particle of the lower surface, and cleans the lower surface, oxygen using ozonated deionized water Change the lower surface and forming oxide in the lower surface makes the lower surface smooth-out, then it is clear with the pre- clear techniques of SiCoNi Clean lower surface, the oxide formed during the cleaning before removing, can improve the metal closures of contact layer and silicon face it Between metal silicide and silicon face between exposure level, so as to reduce contact resistance, improve the electrical resistance of semiconductor components and devices Energy.In addition, DHF cleaning procedures and the pre- clear works of SiCoNi when replacing forming contact layer in rear grid technique using above cleaning procedure The conventional cleaning process that skill is used in combination, can improve the critical size of the metal closures of contact layer, so as to improve semiconductor element device The electric property of part.

Brief description of the drawings

The attached drawing for forming the part of the application is used for providing further understanding of the present application, the schematic reality of the application Apply example and its explanation is used to explain the application, do not form the improper restriction to the application.In the accompanying drawings：

Fig. 1 is in rear metal silicide technology, using the pre- clear techniques of SiCoNi, to the silicon face of formation metal silicide After being surface-treated, the metal silicide and the corresponding active area and the scanning electron microscope (SEM) photograph of contact layer that are formed；

Fig. 2A is to be contacted in the rear grid technique of the prior art in layer formation process, the structural representation that contact trench etch finishes Figure；

Fig. 2 B are to be contacted in the rear grid technique of the prior art in layer formation process, the structural representation after contact groove cleaning Figure；

Fig. 2 C are to be contacted in the rear grid technique of the prior art in layer formation process, form metal silicide and deposited metal plug Structure diagram after material；

Fig. 3 A are in the cleaning procedure of the contact groove of the application preferred embodiment, and contact groove is carried out using SC1 cleaning solutions Clean structure diagram；

Fig. 3 B are in the cleaning procedure of the contact groove of the application preferred embodiment, using ozonated deionized water to contact groove Carry out clean structure diagram；

Fig. 3 C are in the cleaning procedure of the contact groove of the application preferred embodiment, using the pre- clear techniques of SiCoNi to contact groove Carry out clean structure diagram；

After Fig. 3 D are the cleaning procedure using the contact groove of the application preferred embodiment, the structure of metal silicide is formd Schematic diagram；

Fig. 4 is the cleaning procedure of the contact groove using the application preferred embodiment in rear metal silicide technology to silicon table After face is surface-treated, the metal silicide of formation and corresponding active area and the scanning electron microscope (SEM) photograph of contact layer；

Fig. 5 is the flow diagram of the forming method of the contact layer of the application preferred embodiment；

When Fig. 6 A are the forming methods using the contact layer of the application preferred embodiment in rear grid technique, contact trench etch is complete Complete structure diagram；

When Fig. 6 B are the forming methods using the contact layer of the application preferred embodiment in rear grid technique, contact groove has cleaned Structure diagram after finishing；

When Fig. 6 C are the forming methods using the contact layer of the application preferred embodiment in rear grid technique, metal silication is formed Structure diagram after thing and deposited metal plug material.

Embodiment

Describe the application in detail below with reference to the accompanying drawings and in conjunction with the embodiments.It should be noted that in the feelings not conflicted Under condition, the feature in embodiment and embodiment in the application can be mutually combined.

It should be noted that term used herein above is merely to describe embodiment, and be not intended to restricted root According to the illustrative embodiments of the application.As used herein, unless the context clearly indicates otherwise, otherwise singulative Be also intended to include plural form, additionally, it should be understood that, when in the present specification using belong to "comprising" and/or " bag Include " when, it indicates existing characteristics, step, operation, device, component and/or combinations thereof.

For the ease of description, spatially relative term can be used herein, as " ... on ", " ... top ", " ... upper surface ", " above " etc., for describing such as a device shown in the figure or feature and other devices or spy The spatial relation of sign.It should be appreciated that spatially relative term is intended to comprising the orientation except device described in figure Outside different azimuth in use or operation.For example, if the device in attached drawing is squeezed, it is described as " in other devices It will be positioned as " under other devices or construction after the device of part or construction top " or " on other devices or construction " Side " or " under other devices or construction ".Thus, exemplary term " ... top " can include " ... top " and " in ... lower section " two kinds of orientation.The device can also other different modes positioning (being rotated by 90 ° or in other orientation), and And respective explanations are made to the opposite description in space used herein above.

As background technology is introduced, there is the semiconductor components and devices caused by the cleaning procedure of contact groove in the prior art The technical problem that electric property lowers.To solve the technical problem, the application provides a kind of cleaning procedure of contact groove, including such as Lower step：Step S1, the lower surface of contact groove is cleaned using SC1 cleaning solutions, removes the particle of the lower surface；Step S2, After step S1, which is cleaned using ozonated deionized water (DIW), aoxidizes the lower surface and in the lower surface Forming oxide makes the lower surface smooth-out；Step S3, after step S2, the bottom is cleaned using the pre- clear techniques of SiCoNi Surface, removes the oxide formed in step s 2.

Due to the lower surface using SC1 cleaning solutions cleaning contact groove, the particle of the lower surface is removed, and is used smelly Oxidation deionized water cleans the lower surface, and aoxidizing the lower surface and forming oxide in the lower surface makes the lower surface It is smooth-out, then the lower surface is cleaned with the pre- clear techniques of SiCoNi, the oxide formed during the cleaning before removing can To improve exposure level between the metal silicide between the metal closures of contact layer and silicon face and silicon face, so as to reduce contact Resistance, improves the electric property of semiconductor components and devices.In addition, replace forming contact layer in rear grid technique using above cleaning procedure When the conventional cleaning process that uses of the pre- clear process integration of DHF cleaning procedures and SiCoNi, the metal closures of contact layer can be improved Critical size, so as to improve the electric property of semiconductor components and devices.

Wherein, the formula of SC1 cleaning solutions is NH₄OH：H₂O₂：H₂O.Due to H₂O₂Effect, silicon chip surface has one layer of nature Oxide-film SiO₂, in hydrophily, liquid can be cleaned between silicon chip surface and particle and is impregnated with.Due to the natural oxidizing layer of silicon chip surface Si with silicon chip surface is by NH₄OH corrodes, therefore the particle for being attached to silicon chip surface is just fallen into cleaning solution, so as to reach removal The purpose of particle.In NH₄While OH corrosion of silicon surfaces, H₂O₂New oxide-film is formed on oxidized silicon chip surface again.Therefore, SC1 cleaning solutions undercut and remove surface particles to aoxidize with microetch, also can remove slight organic pollution and part metals Change pollutant.Preferably, in above step S1, the volume ratio of each component is preferably NH in SC1 cleaning solutions₄OH：H₂O₂：H₂O= 1：1~4：50~200, the volume ratio of each component is more preferably NH₄OH：H₂O₂：H₂O=1：2~3：100~150, use Cleaning temperature is preferably 23 DEG C to 25 DEG C of room temperature, and cleaning duration is preferably 30s to 120s.Select above parameter area Advantage is both to remove particle and metallic pollution, again few to side wall erosion amount.In step s 2, ozonated deionized water can be with oxygen SiClx surface forms silica.Wherein, O in ozonated deionized water₃Concentration be preferably 10ppm to 80ppm, the temperature of use Preferably 23 DEG C to 25 DEG C of room temperature, cleaning duration is preferably 30s to 120s.The advantage of selection above parameter area is Remove organic contamination, also oxidable bottom silicon, and can prevent the absorption to impurity.The raw material of the pre- clear techniques of SiCoNi is NF₃With NH₃.The pre- clear techniques of SiCoNi provide a kind of low intensive chemical etching method and remove oxide film dissolving, have for silica erosion Extraordinary selectivity, reduces the loss of silicon base and the change of profile.In step s3 preferably, the lower surface of contact groove The removal quantity of oxide beWhat is provided in above step S1 and step S2 is preferable temperature, but the present invention does not arrange Except suitably relaxing temperature range in some cases.

Fig. 3 A to Fig. 3 D show the cleaning procedure flow diagram of the contact groove of the application preferred embodiment.Wherein, scheme 3A is in the cleaning procedure of the contact groove of the application preferred embodiment, and clean structure is carried out to contact groove using SC1 cleaning solutions Schematic diagram；Fig. 3 B are in the cleaning procedure of the contact groove of the application preferred embodiment, using ozonated deionized water to contact groove Carry out clean structure diagram；Fig. 3 C are in the cleaning procedure of the contact groove of the application preferred embodiment, pre- using SiCoNi Clear technique carries out clean structure diagram to contact groove；Fig. 3 D are the cleaners using the contact groove of the application preferred embodiment After skill cleans contact groove, the structure diagram of metal silicide is formd.In Fig. 3 A to Fig. 3 D, each label represents respectively：1 is Silicon substrate, 2 be STI, and 3 be doped region (such as N+ areas or P+ areas), and 4 be high-K metal gate, and 5 be SiN layer, and 6 be ILD layer, and 9 be metal Silicide, 12 be the oxide of silicon substrate material, and 19 represent contact groove.

Fig. 4 shows the cleaning procedure pair of the contact groove using the application preferred embodiment in rear metal silicide technology After silicon face is surface-treated, the metal silicide of formation and corresponding active area and the scanning electron microscope (SEM) photograph of contact layer.Such as Fig. 4 It is shown, wherein, metal silicide 20 (such as NiPtSi metal silicides) is arranged at the silicon face of active area 10 and the gold of contact layer Between belonging to plug 30, due to before forming metal silicide 20 using the SC1 cleaning solutions in the application, ozonated deionized water and The pre- clear techniques of SiCoNi are surface-treated the lower surface of contact groove, therefore, the silicon of metal silicide 20 and active area 10 Connecting portion between surface is smoother, so that the contact resistance between metal silicide 20 and active area 10 is relative to Fig. 1 institutes Reduce for the corresponding prior art, the electric property of corresponding semiconductor components and devices is improved.

The application also provides a kind of forming method of contact layer, and the forming method of the contact layer includes the following steps：Step S20, performs etching inter-level dielectric to form contact groove；Step S40, using foregoing SC1 cleaning solutions, ozone after step S20 Change deionized water and the pre- clear clean cleaning procedures of process integration of SiCoNi clean the surface of contact groove；Step S60, After step S40, the first metal is deposited in the lower surface of contact groove and forms metal silicide；Step S80, in step S60 The second metal is deposited in contact groove afterwards and forms contact layer.

Fig. 5 is the flow diagram of the forming method of the contact layer of the application preferred embodiment.As shown in figure 5, this is preferred In embodiment：

Step S10 is carried out first, and CMP is carried out to inter-level dielectric.

Step S20 is carried out after step 10, step 20 includes the techniques such as photoresist coating, exposure, photoetching and to layer Between medium etch to form contact groove.

Employed successively in used cleaning procedure in step s 40 the cleaning procedure of aforementioned contact groove to contact groove into Row cleaning, therefore, step S40 specifically includes foregoing step S1, S2 and S3.

Step S60 includes：Sub-step 62, deposits the first metal in the lower surface of contact groove；Sub-step 64, carries out heat Annealing, forms metal silicide；Sub-step 66, removes unreacted first metal.

In this preferred embodiment, the first metal deposited in sub-step 62 is NiPt, and the wherein ratio of Pt is preferably 5% ~10% mass percent.Certainly, the present invention is not limited thereto, and the first metal, which can also be that W etc. is other, can form conductive metal The metal of silicide.

Sub-step S64 is preferably included：S641 step by step, first carries out a thermal annealing (first RTA) to generate Ni₂PtSi；S643 step by step, carries out second heat annealing (second RTA) to generate NiPtSi metallic silicons after S641 step by step Compound.At this time, sub-step S66 is carried out between S641 step by step and step by step S643.

Wherein, the thermal annealing carried out step by step in S641 is low temperature thermal annealing, temperature range be preferably 230 DEG C extremely 300 DEG C, more preferably 250 DEG C or so；Annealing time is preferably 20 to 40s, more preferably 30s or so.Step by step The secondary thermal annealing carried out in S643 can be high-temperature thermal annealing, and temperature range is is preferably 450 DEG C to 600 DEG C, more preferably Ground is 550 DEG C or so；Annealing time is preferably 20s to 40s, more preferably 30s or so.Alternatively, the secondary thermal annealing can Think laser annealing, the temperature of laser annealing is preferably 800 DEG C to 900 DEG C, more preferably 850 DEG C or so.Laser annealing with Second heat annealing process can be achieved compared to moment in high-temperature thermal annealing, and annealing time is greatly reduced.

In addition, in sub-step S66 at a temperature of 120 DEG C to 150 DEG C, using the mixture of sulfuric acid and hydrogen peroxide (SPM) Wet method stripping is carried out to the first metal.SPM has very high oxidability, is dissolved in after can metal be aoxidized in cleaning solution, and energy Oxidation operation is generated CO₂And H₂O.It can remove the heavy organic contaminant and part metals of silicon chip surface with SPM cleaning silicon chips.

Second metal is W in the present embodiment.Certainly, the second metal can be adapted as contact layer material it is other Metal, such as silver.

Formation when Fig. 6 A to Fig. 6 C are the forming methods using the contact layer of the application preferred embodiment in rear grid technique The structure diagram of the main flow node of contact layer.Wherein：Fig. 6 A are that the application preferred embodiment is used in rear grid technique During the forming method of contact layer, the structure diagram that finishes of contact trench etch, i.e. structure after step S20 is finished in Fig. 5 Schematic diagram；When Fig. 6 B are the forming methods using the contact layer of the application preferred embodiment in rear grid technique, contact groove has cleaned Structure diagram after finishing, i.e. structure diagram after step S40 is finished in Fig. 5；Fig. 6 C are using this in rear grid technique When applying for the forming method of the contact layer of preferred embodiment, metal silicide (such as NiPtSi) and deposited metal plug material are formed Structure diagram after step S60 and S80 are finished in structure diagram after (such as W), i.e. Fig. 5.

In Fig. 6 A to Fig. 6 C, each label represents respectively：1 is silicon substrate, and 2 be STI, and 3 be doped region, and 4 be high-K metal Grid, 5 be SiN layer, and 6 is form ILD layer, and 7 be coarse silicon face, and 8 be smooth silicon face, and 9 be metal silicide, and 11 be contact layer Metal closures, 19 represent contact groove.

As shown in Fig. 6 A to Fig. 6 C, due to using foregoing SC1 cleaning solutions, ozonated deionized water and the pre- clear works of SiCoNi Skill combines clean cleaning procedure and contact groove is cleaned, and the prior art is instead of with SC1 cleaning solutions, ozonated deionized water In DHF cleaning solutions, so as to reduce the removal total amount of ILD wall films, therefore, improve in the prior art because DHF is cleaned HF becomes larger the critical size of the metal closures of contact groove caused by the etching of oxide in liquid, and the metal closures of contact layer shorten Phenomenon, the critical size of metal closures is more met design requirement, thus be conducive to improve semiconductor components and devices, especially line width For the electric property of the semiconductor components and devices of below 20nm.

Below with reference to embodiment and comparative example, the beneficial effect of the application is further illustrated.

Embodiment 1

Inter-level dielectric is performed etching to form contact groove；It is pre- clear using SC1 cleaning solutions, ozonated deionized water and SiCoNi The clean cleaning procedure of process integration cleans the surface of contact groove according to the operating condition of embodiment 1 in table 1；Cleaning NiPt is deposited in the lower surface of contact groove afterwards as the first metal, and thermal annealing is carried out to the first metal and forms metal silication Thing；Deposition W as the second metal and forms contact layer in contact groove and on metal silicide.A thermal annealing in embodiment 1 For low temperature thermal annealing, second heat is annealed into high-temperature thermal annealing.

Embodiment 2

Identical with 1 step of embodiment, the operation of the cleaning process of SC1 and the cleaning process of ozonated deionized water is according to table The parameter of embodiment 2 is implemented in 1.A thermal annealing is low temperature thermal annealing in embodiment 2, and second heat is annealed into high-temperature thermal annealing.

Embodiment 3

Identical with 1 step of embodiment, the operation of the cleaning process of SC1 and the cleaning process of ozonated deionized water is according to table The parameter of embodiment 3 is implemented in 1.A thermal annealing is low temperature thermal annealing in embodiment 3, and second heat is annealed into laser annealing.

Embodiment 4

Identical with 1 step of embodiment, the operation of the cleaning process of SC1 and the cleaning process of ozonated deionized water is according to table The parameter of embodiment 4 is implemented in 1.A thermal annealing is low temperature thermal annealing in embodiment 4, and second heat is annealed into laser annealing.

Embodiment 5

Identical with 1 step of embodiment, the operation of the cleaning process of SC1 and the cleaning process of ozonated deionized water is according to table The parameter of embodiment 5 is implemented in 1.A thermal annealing is low temperature thermal annealing in embodiment 5, and second heat is annealed into laser annealing.

Comparative example 1

Clean scavenger is carried out to contact groove using the pre- clear process integration of the DHF cleaning procedures and SiCoNi of the prior art Skill is implemented.

Table 1

Understood through each embodiment 1 to 5 and the contrast of comparative example 1, (effect of embodiment 1 is shown in Fig. 4, implements in embodiment 1 to 5 Example 2 to 5 is approximate with the effect of embodiment 1) in it is smooth between metal silicide and silicon face, the longitudinal directions of the metal closures of contact layer is cut Face above-below direction change is smaller.And (effect is shown in Fig. 1) is uneven between metal silicide and silicon face in comparative example 1, contact The longitudinal cross-section of the metal closures of layer is up big and down small.It can be seen from the above that contact trench bottom table can be made using the cleaning procedure of the application Face becomes smooth, helps to improve the structure of metal silicide, the critical size of the metal closures of contact layer is more met design and wants Ask, be conducive to improve the electric property of semiconductor.

From the above description, it can be seen that the above example of the application has the following advantages that：

By SC1 cleaning solutions and ozonated deionized water and the pre- clear process integrations of SiCoNi to contact the surface of trench bottom into Row cleaning, makes the surface become smooth, helps to improve the structure of metal silicide, improves connecing for metal silicide and silicon face Get an electric shock and hinder, so as to improve the electric property of corresponding semiconductor component.

In rear grid technique, the metal suicide structure before the metal closures of contact layer are formed uses the application when being formed Foregoing cleaning procedure not only make the lower surface of contact groove smooth, and the critical size of contact layer metal closures can be improved, Improve the electric property of corresponding semiconductor component.

The foregoing is merely the preferred embodiment of the application, the application is not limited to, for the skill of this area For art personnel, the application can have various modifications and variations.It is all within spirit herein and principle, made any repair Change, equivalent substitution, improvement etc., should be included within the protection domain of the application.

Claims

1. a kind of cleaning procedure of contact groove, it is characterised in that the cleaning procedure includes the following steps：

Step S1：The lower surface of the contact groove is cleaned using SC1 cleaning solutions, removes the particle of the lower surface；

Step S2：After the step S1, the lower surface is cleaned using ozonated deionized water, aoxidizes the lower surface And forming oxide in the lower surface makes the lower surface smooth-out；

Step S3：After the step S2, the lower surface is cleaned using the pre- clear techniques of SiCoNi, is removed in the step S2 The oxide of middle formation.

2. cleaning procedure according to claim 1, it is characterised in that each in the SC1 cleaning solutions in the step S1 The volume ratio of component is NH₄OH：H₂O₂：H₂O=1：1~4：50~200.

3. cleaning procedure according to claim 1, it is characterised in that in the step S1, the cleaning temperature that uses for 23 DEG C to 25 DEG C of room temperature.

4. cleaning procedure according to claim 1, it is characterised in that in the step S1, cleaning duration is 30s to 120s.

5. cleaning procedure according to claim 1, it is characterised in that in the step S2, the ozonisation deionization O in water₃Concentration be 10ppm to 80ppm.

6. cleaning procedure according to claim 1, it is characterised in that in the step S2, the cleaning temperature that uses for 23 DEG C to 25 DEG C of room temperature.

7. cleaning procedure according to claim 1, it is characterised in that in the step S2, cleaning duration is 30s to 120s.

8. cleaning procedure according to claim 1, it is characterised in that in the step S3, the removal of the oxide Measure and be

9. a kind of forming method of contact layer, it is characterised in that the forming method includes the following steps：

Step S20：Inter-level dielectric is performed etching to form contact groove；

Step S40：After the step S20, using the cleaning procedure of the contact groove according to any one of claim 1 to 8 The lower surface of the contact groove is cleaned；

Step S60：After the step S40, the first metal is deposited in the lower surface of the contact groove and forms metallic silicon Compound；

Step S80：After the step S60, the second metal is deposited in the contact groove to form contact layer.

10. forming method according to claim 9, it is characterised in that the step S60 includes：

Sub-step S62：First metal is deposited in the lower surface of the contact groove；

Sub-step S64：Thermal annealing is carried out, forms metal silicide；

Sub-step S66：Remove unreacted first metal.

11. forming method according to claim 9, it is characterised in that first metal is NiPt or W.

12. forming method according to claim 10, it is characterised in that

First metal deposited in the sub-step S62 is NiPt；

The sub-step S64 includes：S641 step by step, carries out a thermal annealing to generate Ni₂PtSi；S643 step by step, described Second heat annealing is carried out after S641 step by step to generate NiPtSi metal silicides；

The sub-step S66 is carried out between the S641 step by step and the S643 step by step.

13. forming method according to claim 12, it is characterised in that

Thermal annealing is low temperature thermal annealing, and the temperature of low temperature thermal annealing is 230 DEG C to 300 DEG C, annealing time for 20s extremely 40s；

The second heat is annealed into high-temperature thermal annealing, and the temperature of high-temperature thermal annealing is 450 DEG C to 600 DEG C, annealing time for 20s extremely 40s, or the secondary thermal annealing use laser annealing, and the temperature of laser annealing is 800 DEG C to 900 DEG C.

14. forming method according to claim 10, it is characterised in that in the sub-step S66, using sulfuric acid and dioxygen The mixture of water carries out wet method stripping to first metal.