CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is a U.S. National Stage Application under 35 U.S.C. § 371 of PCT Application No. PCT/KR2017/000357, filed Jan. 11, 2017, which claims priority to Korean Patent Application No. 10-2016-0097788, filed Aug. 1, 2016, whose entire disclosures are hereby incorporated by reference.

TECHNICAL FIELD

The present embodiments relate to a polishing measurement device and a abrasion time controlling method thereof, and a polishing control system including same, and more particularly to a polishing measurement device and a abrasion time controlling method thereof for enhancing the polishing precision (flatness) of a wafer surface, and a polishing control system including same.

BACKGROUND ART

A wafer, which becomes a substrate during fabricating a semiconductor is fabricated through an ingot growing process for growing an ingot used as a raw material, a slicing process for slicing an ingot into a wafer shape, a lapping process for uniformizing and planarizing a thickness of a wafer, an etching process for removing and mitigating an occurred damage, a polishing process for mirror-polishing a surface of a wafer, and a cleaning process for cleaning a wafer and removing foreign substances adhered to a surface.

During the above-described process, a defect may occur on a surface and subsurface of a wafer. Types of defects include particles, scratches, crystal defects, subsurface roughness, and the like.

Nowadays, restrictions on the above-described surface defects of a wafer are rapidly strengthened, and in particular, as the wafer has a large-scale diameter, it is required to implement a high-quality defect-free wafer due to a processing characteristic of the wafer of a large-scale diameter.

However, a conventional polishing apparatus cannot precisely apply a polishing time, and surface defects of the wafer still occurred.

For example, a thickness measuring apparatus of a wafer surface disclosed in Japanese Patent Application Laid-Open No. 2008-227393 is disposed in a support frame away from an upper surface plate of a polishing apparatus, measures a thickness of a wafer surface without being influenced by vibration of rotation of the upper surface plate, and applies a polishing time to the polishing apparatus according to the measured thickness of the wafer surface to polish the wafer surface.

However, in the related art, since one polishing apparatus is controlled by each controller for controlling the above-described thickness measuring apparatus, installation cost of the controller and the like is increased, and measurement accuracy of a thickness is lowered due to limitation of the number of measurements of the wafer and a processing environment of a slurry.

DISCLOSURE

Technical Problem

The present embodiments are directed to providing a polishing measurement device and a abrasion time controlling method thereof for computing a correction value according to a surface shape of a wafer and reflecting the correction value on a polishing end point time, and a polishing control system including same.

In addition, the present embodiments are directed to providing a polishing measurement device and a abrasion time controlling method thereof for applying a polishing end point time to a controller for each polishing apparatus, and a polishing control system including same.

Technical Solution

According to an embodiment, there is provided a polishing measurement device, including: a shape scan unit configured to scan a wafer shape provided from at least one controller controlling a polishing time of each wafer; a profile determination unit configured to compute a thickness of the scanned wafer shape to determine at least one profile for a wafer type; an end point time computation unit configured to compute a PV value by the determined profile and compute a delta correction value and a polishing end point time by using the computed PV value and a set predicted PV value; and a polishing time change unit configured to transmit the computed polishing end point time to the at least one controller to change a polishing time of each of the wafers which is under polishing.

The wafer shape may be a result generated according to the polishing time.

The profile determination unit may compute a thickness by location located on the same line of each of the wafers.

The thickness may include at least one of a maximum thickness, a minimum thickness, an average thickness, a ¼ thickness, a 2/4 thickness and a ¾ thickness of each of the wafers by location.

The at least one profile may include convex shape, W shape, M shape and concave shape distinguished on the basis of the computed thickness of the wafer shape.

The delta correction value may be the predicted PV value−the PV value, and the polishing end point time may be a control time according to the PV value+/−the delta correction value.

The predicted PV value may be a predicted value based on a predicted polishing time by the at least one profile or environmental factors affecting the polishing time.

According to an embodiment, there is provided a polishing control system, including: a polishing measurement device configured to compute a thickness of a scanned wafer shape to determine at least one profile for a wafer type, and compute a delta correction value and a polishing end point time by using a computed PV value by the determined profile and a set predicted PV value; at least one controller configured to apply a polishing time of each of the wafers to a following polishing apparatus to obtain a shape of the wafer which is under polishing, and change the polishing time to the computed polishing end point time; and the polishing apparatus configured to primarily polish a surface of each of the wafers according to the polishing time and secondarily polish the surface of each of the wafers according to the changed polishing end point time.

The polishing apparatus may compute a thickness by location of each of the wafers located on the same line.

The thickness may include at least one of a maximum thickness, a minimum thickness, an average thickness, a ¼ thickness, a 2/4 thickness and a ¾ thickness of each of the wafers by location.

The at least one profile may include convex shape, W shape, M shape and concave shape distinguished on the basis of the computed thickness of the wafer shape.

The delta correction value may be the predicted PV value−the PV value, and the polishing end point time may be a control time according to the PV value+/−the delta correction value.

The predicted PV value may be a predicted value based on a predicted polishing time by the at least one profile or environmental factors affecting the polishing time.

According to an embodiment, there is provided a abrasion time controlling method, as a method for controlling a polishing end point time for each wafer of a plurality of controllers by a polishing measurement device, including: scanning a wafer shape provided from at least one controller; computing a thickness by location located on the same line of each of the wafers based on the scanned wafer shape; determining at least one profile for a wafer type based on the computed thickness by location; computing a PV value by the determined profile, and computing a delta correction value and a polishing end point time by using the computed PV value and a set predicted PV value; and changing the polishing time of each of the wafers which is under polishing by transmitting the computed polishing end point time to the at least one controller.

The thickness may include at least one of a maximum thickness, a minimum thickness, an average thickness, a ¼ thickness, a 2/4 thickness and a ¾ thickness of each of the wafers by location.

The at least one profile may include convex shape, W shape, M shape and concave shape distinguished on the basis of the computed thickness of the wafer shape.

The delta correction value may be the predicted PV value−the PV value, and the polishing end point time may be a control time according to the PV value+/−the delta correction value.

The predicted PV value may be a predicted value based on a predicted polishing time by the at least one profile or environmental factors affecting the polishing time.

Advantageous Effects

As described above, in the present embodiments, a correction value for each profile of a wafer type may be computed and a polishing time may be changed, and thus excellent flatness of a wafer surface without defects on the wafer surface can be achieved.

In addition, in the present embodiments, a plurality of controllers may be controlled by one polishing measurement device, and thus equipment cost can be significantly reduced.

The advantageous effects are not limited thereto, and other effects not described may be clearly understood by those skilled in the art from the description below.

