CN102380816A

CN102380816A - Chemically mechanical polishing method and system

Info

Publication number: CN102380816A
Application number: CN201010269946XA
Authority: CN
Inventors: 沈孟仪; 胡良友; 何宗轩; 曾胜义
Original assignee: Macronix International Co Ltd
Current assignee: Macronix International Co Ltd
Priority date: 2010-08-30
Filing date: 2010-08-30
Publication date: 2012-03-21

Abstract

The invention discloses a chemically mechanical polishing method, which includes steps of providing a plurality of semiconductor elements to be polished, obtaining the size of each of the semiconductor elements to be polished, and polishing each semiconductor element according to the size of the semiconductor element. By the aid of the method, a feedback control flow in the prior art is omitted, element polishing thickness in the chemically mechanical polishing technology can be accurately controlled, and further yield loss is remarkably reduced, and product quality is improved.

Description

Cmp method and system

Technical field

The invention relates to a kind of cmp method and system, particularly control about the advanced technologies of CMP process.

Background technology

Because the size of semiconductor element is constantly dwindled, thereby the importance of the surperficial whole district planarization (Global Planarization) of element in semiconductor technology also promotes day by day.The wafer surface whole district flattening method that the most generally adopts at present is chemically mechanical polishing (Chemical Mechanical Polishing; CMP) technology; It is wafer surface to be pressed on the polishing pad that is covered with polishing fluid rotate, with the having an even surface with entire wafer.

When adopting CMP technology to polish semiconductor element, polishing time be after can causing excessive polishing (Over Polish) for a long time, and the resistance of each metal wire is with the too high and element speeds that slows down on this moment element, and the dielectric layer on it also can be badly damaged; And of a specified duration inadequately when the time of polishing, when causing metal on the dielectric layer not remove fully, promptly claim directional polish (Under Polish) phenomenon, also can influence element function.Therefore, the polished thickness of control element in CMP technology can avoid producing the phenomenon of above-mentioned excessive polishing or directional polish, to improve the yield of product.

Please with reference to Fig. 1, it is prior art is controlled polishing thickness in CMP technology a method, and the method is to use feedback to control to adjust the polishing time of wafer.At first; Get 2～3 wafers and carry out thickness measure and polishing test (step 10); And estimate the best polishing time (step 11) of first batch of (Lot) wafer with this test result; With this through best polishing time of estimating polish this first batch wafers (step 12), after this first batch wafers is accomplished the CMP glossing, the thickness (step 13) after the polishing of this first batch wafers of sampling measurement again; And this measurement result fed back to the next batch wafer, to estimate the best polishing time (step 14) of next batch wafer.

As stated, in existing C MP control method, only estimate the burnishing parameters of first batch wafers, therefore cause high yield loss (yield loss) with sample mode; In addition; Adopt feedback control system to estimate the burnishing parameters of follow-up batch wafers; Not only cost is higher, and only provides the polishing time of an estimation also can't precisely control the polishing thickness of each wafers to a collection of wafer, thereby can't show reduction polishing mortality.

For solving above-mentioned prior art problems, the present invention proposes a kind of cmp method and system, to improve efficient, accuracy and the stability of semiconductor element technology.

Summary of the invention

The present invention proposes a kind of cmp method and system, need not to adopt the feedback control flow of prior art, can accurately control the element polishing thickness in the CMP technology, and then is showing the reduction yield loss and improve the quality of products.

One side of the present invention provides a kind of cmp method, comprises the following step: a plurality of semiconductor elements are provided; Obtain a size of each semiconductor element in these a plurality of semiconductor elements; And polish this each semiconductor element according to this size of this each semiconductor element.

Another aspect of the present invention provides a kind of method that is used for a CMP process, and this method comprises the following step: a plurality of objects are provided, and wherein each object has a physical parameter; Obtain those physical parameters of all these a plurality of objects; And according to this physical parameter of this each object with determine this each object proprietary burnishing parameters.

Of the present invention a kind of chemical-mechanical polishing system is provided on the one hand again, this system is in order to polishing a plurality of objects, and comprises a measurement mechanism, a determination device and a burnishing device; This measurement mechanism is in order to obtain the physical parameter that each object had in these a plurality of objects; This determination device is to be connected with this measurement mechanism, in order to this physical parameter according to this each object decide this each object proprietary burnishing parameters; This burnishing device is to be connected with this determination device, in order to according to this each object proprietary burnishing parameters polish this each object.

Description of drawings

Fig. 1: the CMP process of prior art;

Fig. 2 (A) a: embodiment of cmp method of the present invention;

One embodiment of the step 22 among Fig. 2 (B): Fig. 2 (A);

Fig. 3: another embodiment of cmp method of the present invention;

Fig. 4 a: sketch map of chemical-mechanical polishing system of the present invention;

Fig. 5 (A): the sketch map of the average thickness of a plurality of batch wafers before polishing; And

Fig. 5 (B): the sketch map that uses the average thickness of a plurality of batch wafers after cmp method of the present invention and system polish.

[main element symbol description]

10 get 2～3 wafers measures thickness and the step of polishing test

11 estimate the step of the best polishing time of first batch wafers

The step of 12 polishings, first batch wafers

The step of the thickness of 13 sampling measurements, first batch wafers

14 estimate the step of the best polishing time of next batch wafer

20 provide the step of a plurality of semiconductor elements

21 obtain the step of each semi-conductive size

22 polish this each semiconductor element according to this size of each semiconductor element

The step of part

Step between a plurality of size field of 221 definition

222 according to providing between the size field under the size of each semiconductor element respectively

The step of polishing prescription

223 polish each semiconductor element according to other polishing prescription of this branch step

31 provide the step of a plurality of objects

32 obtain the step of the physical parameter of all objects

33 according to the physical parameter of each object with determine each object proprietary throwing

The step of optical parameter

4 chemical-mechanical polishing systems

40 corresponding tables

41 measurement mechanisms

42 determination devices

43 burnishing devices

The specific embodiment

Technological means of the present invention will specify as follows, believe the object of the invention, characteristic and characteristics, go deep into and concrete understanding when getting one thus, yet the following example only provide reference and explanation usefulness with diagram, is not to be used for the present invention is limited.

Please refer to Fig. 2 (A), it is an embodiment of cmp method of the present invention.This cmp method comprises the following steps: to provide a plurality of semiconductor elements (step 20); Utilize the element measurement means of measuring in board or other CMP technology, obtain a size (step 21) of each semiconductor element in these a plurality of semiconductor elements; And, polish this each semiconductor element (step 22) according to this size that derives from this each semiconductor element of step 21.

According to above-mentioned conception, these a plurality of semiconductor elements for example are a plurality of wafers, also can be other the polished object that is applicable to CMP technology.

For instance; The metering system of step 21 is: this size of measuring this each semiconductor element one by one is to obtain a sized data of each semiconductor element; This sized data can comprise a thickness of this semiconductor element; Or the thickness of each material layer in this semiconductor element, this thickness is unit with dust

for example.

Please refer to Fig. 2 (B), it is an embodiment of step 22 among Fig. 2 (A).Step 22 can comprise the following steps: to define between a plurality of size field, a corresponding separately specific polishing prescription (step 221) between each size field; According to pairing this specific polishing prescription between the size field under this size of this each semiconductor element and between this each size field, come to be this each semiconductor element other polishing prescription (step 222) that provides a fen; And polish this each semiconductor element (step 223) according to other polishing prescription of this branch.

According to above-mentioned conception, the corresponding tables example of setting between this size field and specific polishing prescription is as shown in table 1, and can design or adjust the content of corresponding tables according to various polished object kind or polishing machine platform parameter.

Table 1

X in the table 1 representative is not when that a measured element thickness does not drop on is preset when interval, and system just can not be that this element produces polishing and fills a prescription.

According to above-mentioned conception, other polishing prescription of this branch comprises the polishing time to each semiconductor element, also can comprise other burnishing parameters such as temperature, pressure or polishing material in addition; Can comprise at least 20 intervals between said size field; And the interval difference of one between said size field for example is noted that for about 100 dusts

that the interval quantity that is comprised between said size field and this interval difference between each interval all can design according to the actual needs of glossing.

Please refer to Fig. 3, it is another embodiment of cmp method of the present invention.This cmp method comprises the following steps: to provide a plurality of polished objects (step 31), and wherein each object in these a plurality of objects has a physical parameter; Obtain these physical parameters (step 32) of all these a plurality of objects; And according to this physical parameter of this each object with determine this each object proprietary burnishing parameters (step 33); Wherein step 32 for example is: a size of measuring this each object one by one is to obtain these physical parameters of all these a plurality of objects; Wherein this physical parameter comprises a thickness of this object at least, and this burnishing parameters comprises a polishing time at least.

According to above-mentioned conception, this object is a semiconductor element, for example is a wafer.

Please refer to Fig. 4, it is an embodiment of chemical-mechanical polishing system of the present invention.This chemical-mechanical polishing system 4 comprises: a measurement mechanism 41, in order to obtain the physical parameter that each object had in a plurality of polished objects; One determination device 42 is connected with this measurement mechanism 41, in order to this physical parameter according to this each object decide this each object proprietary burnishing parameters; And a burnishing device 43, be connected with this determination device 42, in order to according to this each object proprietary burnishing parameters polish this each object.In Fig. 4, the throughput direction of direction of arrow representative object in chemical-mechanical polishing system 4.

According to above-mentioned conception; This determination device 42 for example is a polishing prescription generator; It can in build or import a for example corresponding tables 40 of table 1 by operating personnel; After this determination device 42 receives this physical parameter of this each object from this measurement mechanism 41, can produce specific polishing prescription for this each object according to this physical parameter of this each object and this corresponding tables 40, this specific polishing prescription promptly comprise this each object proprietary burnishing parameters.

According to above-mentioned conception, this object is a semiconductor element, for example is a wafer; This physical parameter of this each element comprises a thickness of this each object at least, and this burnishing parameters comprises a polishing time at least.

Please refer to Fig. 5 (A) and Fig. 5 (B); Wherein Fig. 5 (A) is depicted as the average thickness of each batch wafers before polishing of 25 batches wafer; Fig. 5 (B) is then for using cmp method of the present invention and system to polish after the said 25 batches wafer; The average thickness of each batch wafers can find out that the thickness of the semiconductor element that uses finishing method of the present invention and system can make the polishing completion is quite average.

In sum; Every batch of object polishes according to feedback signal in loop circuit (closed-loop) control system compared to prior art; The present invention adopts the automated system of opening loop (open-loop) to come that each polished object generation one polishing prescription in the CMP technology is had the advantage that reduces the simultaneously accurate control element polishing thickness of system authority complexity.Being that to show the various prior aries that exist at present with, the present invention be excellent, very is one to have the creation of industrial value.

Though the present invention discloses as above with a plurality of preferred embodiments; Right its is not in order to limit the present invention; Anyly have the knack of this art; Do not breaking away from the spirit and scope of the present invention, when can doing a little change and retouching, so protection scope of the present invention is when looking being as the criterion that the claim scope of enclosing defined.

Claims

1. cmp method comprises:

A plurality of semiconductor elements are provided;

Obtain a size of each semiconductor element in these a plurality of semiconductor elements; And

Polish this each semiconductor element according to this size of this each semiconductor element.

2. method according to claim 1, wherein these a plurality of semiconductor elements are a plurality of wafers.

3. method according to claim 1, the wherein said step that obtains this size of this each semiconductor element comprises this size of measuring this each semiconductor element one by one.

4. method according to claim 1, wherein this size comprises a thickness of this each semiconductor element.

5. method according to claim 1, the step of wherein polishing this each semiconductor element comprises:

Be of a size of this each semiconductor element other polishing prescription that provides a fen according to this of this each semiconductor element; And

Polish this each semiconductor element according to other polishing prescription of this branch.

6. method according to claim 5, wherein other polishing prescription of this branch comprises a polishing time.

7. method according to claim 5, the wherein said step of other polishing prescription of this branch that provides comprises the following step:

Define between a plurality of size field a corresponding separately specific polishing prescription between each size field; And

According to pairing this specific polishing prescription between the size field under this size of this each semiconductor element and between this each size field, coming provides this branch polishing prescription else for this each semiconductor element.

8. method according to claim 7 comprises at least 20 intervals between wherein said size field.

9. method according to claim 7, the interval difference of one between wherein said size field is 100 dusts.

10. method that is used for a CMP process, this method comprises:

A plurality of objects are provided, and wherein each object in these a plurality of objects has a physical parameter;

Obtain those physical parameters of all these a plurality of objects; And

According to this physical parameter of this each object with determine this each object proprietary burnishing parameters.

11. method according to claim 10, wherein this object is a semiconductor element.

12. method according to claim 10, wherein this object is a wafer.

13. method according to claim 10 more comprises the following step:

A size of measuring this each object one by one is to obtain those physical parameters of all these a plurality of objects.

14. method according to claim 10, wherein this physical parameter comprises a thickness of this object.

15. method according to claim 10, wherein this burnishing parameters comprises a polishing time.

16. a chemical-mechanical polishing system comprises:

One measurement mechanism is in order to obtain the physical parameter that each object had in a plurality of objects;

One determination device is connected with this measurement mechanism, in order to this physical parameter according to this each object decide this each object proprietary burnishing parameters; And

One burnishing device is connected with this determination device, in order to according to this each object proprietary burnishing parameters polish this each object.

17. system according to claim 16, wherein this object is a semiconductor element.

18. system according to claim 16, wherein this object is a wafer.

19. system according to claim 16, wherein this physical parameter comprises a thickness of this object.

20. system according to claim 16, wherein this burnishing parameters comprises a polishing time.