CN101515537B

CN101515537B - Polishing endpoint detection method capable of improving detection precision

Info

Publication number: CN101515537B
Application number: CN2008100338169A
Authority: CN
Inventors: 李健
Original assignee: Semiconductor Manufacturing International Shanghai Corp
Current assignee: Semiconductor Manufacturing International Shanghai Corp
Priority date: 2008-02-22
Filing date: 2008-02-22
Publication date: 2011-02-02
Anticipated expiration: 2028-02-22
Also published as: CN101515537A

Abstract

The invention provides a polishing endpoint detection method capable of improving the detection precision, which is used for detecting a polishing endpoint of a chemical-mechanical polishing process of oxide. In the prior art, the detected peak is not judged as the polishing endpoint withoutby detecting the torque of the detected peak when the polishing endpoint of the oxide is detected, so the error detection phenomenon of the polishing endpoint is easy to appear when the polishing speed is too slow. The method performs the polishing in a preset time period and, then detects the polishing endpoint, also judges whether the torque which correspondscorrespondinging to the detected peak is within the range of normal termination torque, and then determines the detected peak is the polishing endpoint when the torque which correspondscorresponding to the detected peak is within the range of normal termination torque. The adoption of Tthe method can avoid prevent error detection events of the polishing endpoint from appearing when the polishing speed is too slow, thereby greatly improvingthus the precision and the reliability of the detection of the polishing endpoint can be greatly improved further to greatly improve the polishing quality of the chemical-mechanical polishing process of the oxide.

Description

A kind of polishing endpoint detection method that detects precision that improves

Technical field

The present invention relates to CMP (Chemical Mechanical Polishing) process, relate in particular to a kind of polishing endpoint detection method that detects precision that improves.

Background technology

Enter epoch of 0.13 micron when semiconductor device after, chemico-mechanical polishing (CMP) technology becomes the necessary operation that semiconductor is made because of the overall planarization that can realize crystal column surface.CMP technology is pressed in wafer on the grinding pad with lapping liquid by grinding head and drives the wafer rotation, and grinding pad then with opposite direction rotation, chemical corrosion has taken place, so CMP technology has had the advantage of mechanical lapping and chemical grinding concurrently in mechanical lapping.In carrying out CMP technology; detecting polishing end point accurately is the key factor of guaranteeing quality of finish; be the precision of guaranteeing that polishing end point detects; now can just begin to carry out polishing end point usually after CMP technology is carried out a preset period of time (being generally 30 seconds) detects; after this crest that detects on the polishing curve is polishing end point; but when some unusual condition; the polishing velocity of chemico-mechanical polishing is very slow; the situation that crest is not its actual polishing end point will appear detecting in this moment, and the phenomenon of removing deficiency for example can appear polishing in the quality that so will influence the chemico-mechanical polishing of oxide.

Therefore, how to provide a kind of polishing endpoint detection method of detecting precision of improving detecting polishing end point accurately, and then improve the quality of finish of the CMP (Chemical Mechanical Polishing) process of oxide, become the technical problem that industry needs to be resolved hurrily.

Summary of the invention

The object of the present invention is to provide a kind of polishing endpoint detection method that detects precision that improves, can improve the precision that polishing end point detects by described end-point detection method, and then improve the quality of finish of oxide chemistry mechanical polishing greatly.

The object of the present invention is achieved like this: a kind of polishing endpoint detection method that detects precision that improves, be used to detect the polishing end point of the CMP (Chemical Mechanical Polishing) process of oxide, this method may further comprise the steps: a, oxide carried out the CMP (Chemical Mechanical Polishing) process of a preset period of time; B, judge whether the polishing curve of CMP (Chemical Mechanical Polishing) process crest occurs,, if not, then continue step b if then continue step c; C, judge that the pairing moment of torsion of this crest whether at a fair termination torque range, is a polishing end point if then judge this crest, then return step b if not.

In the polishing endpoint detection method of above-mentioned improved detection precision, this preset period of time is 30 seconds.

In the polishing endpoint detection method of above-mentioned improved detection precision, this fair termination torque range is greater than 51 Ns of rice.

With only detect in the prior art by after the polishing of carrying out a preset period of time, carrying out polishing end point again, easily occurring the flase drop survey when the slow excessively glossing of polishing velocity is carried out end point determination compares, the polishing endpoint detection method that detects precision that improves of the present invention not only detects by carry out polishing end point again after the polishing of carrying out a preset period of time, judge that also whether the moment of torsion of the crest correspondence that detects is at the fair termination torque range, and judge just that when being the crest that detects is a polishing end point, avoiding crossing the polishing end point flase drop survey incident that occurs when slow in polishing velocity takes place, so can improve precision and reliability that polishing end point detects greatly, and then improve the quality of finish of oxide chemistry mechanical polishing process greatly.

Description of drawings

The polishing endpoint detection method that detects precision that improves of the present invention is provided by following embodiment and accompanying drawing.

Fig. 1 is the flow chart that improves the polishing endpoint detection method that detects precision of the present invention.

Embodiment

Below will be described in further detail the polishing endpoint detection method that detects precision that improves of the present invention.

Of the present inventionly improve the polishing end point that the polishing endpoint detection method that detects precision is used to detect the CMP (Chemical Mechanical Polishing) process of oxide, referring to Fig. 1, described method is at first carried out step S10, oxide is carried out the CMP (Chemical Mechanical Polishing) process of a preset period of time.In the present embodiment, described preset period of time is 30 seconds.

Then continue step S11, judge whether the polishing curve of CMP (Chemical Mechanical Polishing) process crest occurs,, if not, then continue step S11 if then continue step S12.

In step S12, whether judge the pairing moment of torsion of described crest at a fair termination torque range, be polishing end point (step S13) if then judge described crest, then return step S11 if not.In the present embodiment, described fair termination torque range is greater than 51 Ns of rice.

In sum, the polishing endpoint detection method that detects precision that improves of the present invention not only detects by carry out polishing end point again after the polishing of carrying out a preset period of time, judge that also whether the moment of torsion of the polishing end point correspondence that detects is at the fair termination torque range, and judge just that when being the crest that detects is a polishing end point, avoiding crossing the polishing end point flase drop survey incident that occurs when slow in polishing velocity takes place, so can improve precision and reliability that polishing end point detects greatly, and then improve the quality of finish of oxide chemistry mechanical polishing process greatly.

Claims

1. one kind can be improved the polishing endpoint detection method that detects precision, is used to detect the polishing end point of the CMP (Chemical Mechanical Polishing) process of oxide, and this method may further comprise the steps: a, oxide carried out the CMP (Chemical Mechanical Polishing) process of a preset period of time; It is characterized in that this method is further comprising the steps of: b, judge whether the polishing curve of CMP (Chemical Mechanical Polishing) process crest occurs,, if not, then continue step b if then continue step c; C, judge that the pairing moment of torsion of this crest whether at a fair termination torque range, is a polishing end point if then judge this crest, then return step b if not.

2. the polishing endpoint detection method that detects precision that improves as claimed in claim 1 is characterized in that this preset period of time is 30 seconds.

3. the polishing endpoint detection method that detects precision that improves as claimed in claim 1 is characterized in that this fair termination torque range is greater than 51 Ns of rice.