US-20260124714-A1 - PROCESSING METHOD AND PROCESSING APPARATUS

US20260124714A1US 20260124714 A1US20260124714 A1US 20260124714A1US-20260124714-A1

Abstract

A processing method of processing a substrate in a processing apparatus includes performing a first grinding processing on the substrate in a first grinder; performing a second grinding processing on the substrate in a second grinder; performing a first re-grinding processing on the substrate in the first grinder; and performing a second re-grinding processing on the substrate in the second grinder. The substrate is ground to a final thickness in the second re-grinding processing.

Inventors

Takashi Sakaue

Assignees

TOKYO ELECTRON LIMITED

Dates

Publication Date: 20260507
Application Date: 20251229
Priority Date: 20200217

Claims (16)

1 . A processing method of processing a substrate in a processing apparatus, the processing method comprising: performing a first grinding processing on the substrate in a first grinder; performing a second grinding processing on the substrate in a second grinder; performing a re-grinding processing on the substrate in the second grinder such that the substrate is finishing-ground to a final thickness; and measuring a final thickness distribution of the substrate, wherein, for a n th sheet of substrate (n is a natural number equal to or larger than 2) held by a substrate holder, the re-grinding processing is not performed, and the substrate is finishing-ground to the final thickness in the second grinder based on the final thickness distribution measured for a m th sheet of substrate (m is a natural number equal to or larger than 1 and equal to or less than n−1); the processing method further comprising: measuring a thickness distribution of the substrate after being subjected to the second grinding processing; and determining a relative inclination between the substrate holder and the second grinder based on the measured thickness distribution, wherein the second grinder performs the re-grinding processing in a state that the substrate is maintained at the relative inclination between the substrate holder and the second grinder determined based on the thickness distribution.
2 . The processing method of claim 1 , wherein multiple substrates are successively processed in the processing apparatus, and the re-grinding processing is performed on a first sheet of substrate held by the substrate holder.
3 . The processing method of claim 1 , wherein a grinding amount of the substrate in the re-grinding processing is equal to a grinding amount of the substrate in the finishing grinding processing.
4 . The processing method of claim 1 , further comprising: performing a rough grinding to reduce a thickness of the substrate, before the first grinding processing.
5 . The processing method of claim 4 , wherein a grinding amount of the substrate in the rough grinding is larger than grinding amounts of the substrate in the first grinding processing and the second grinding processing.
6 . A processing apparatus configured to perform a grinding processing on a substrate, comprising: a first grinder configured to perform a first grinding processing on the substrate; a second grinder configured to perform a second grinding processing on the substrate; a substrate holder configured to hold the substrate; a thickness distribution measuring device configured to measure a thickness distribution of the substrate after being subjected to the second grinding processing; and a controller configured to control the grinding processing of the substrate, wherein the controller controls the second grinder to perform a re-grinding processing on the substrate such that the substrate is finishing-ground to a final thickness, the controller controls the thickness distribution measuring device to measure a final thickness distribution of the substrate, and for a n th sheet of substrate (n is a natural number equal to or larger than 2) held by the substrate holder, the controller controls the second grinder not to perform the re-grinding processing, and to perform a finishing grinding processing based on the final thickness distribution measured for a m th sheet of substrate (m is a natural number equal to or larger than 1 and equal to or less than n−1), wherein the processing apparatus further comprises an inclination adjusting device configured to adjust a relative inclination between the substrate holder and the second grinder, wherein the controller determines the relative inclination based on the thickness distribution measured after the second grinding processing, and controls the second grinder to perform the re-grinding processing in a state that the substrate is maintained at the determined relative inclination.
7 . The processing apparatus of claim 6 , wherein multiple substrates are successively processed, and the controller controls the second grinder to perform the re-grinding processing on a first sheet of substrate held by the substrate holder.
8 . The processing apparatus of claim 6 , wherein a grinding amount of the substrate in the re-grinding processing is equal to a grinding amount of the substrate in the finishing grinding processing.
9 . The processing apparatus of claim 6 , further comprising: a rough grinding device, wherein the controller controls the rough grinding device to perform a rough grinding to reduce a thickness of the substrate, before the first grinding processing.
10 . The processing apparatus of claim 9 , wherein a grinding amount of the substrate in the rough grinding is larger than grinding amounts of the substrate in the first grinding processing and the second grinding processing.
11 . The processing method of claim 2 , wherein a grinding amount of the substrate in the re-grinding processing is equal to a grinding amount of the substrate in the finishing grinding processing.
12 . The processing method of claim 2 , further comprising: performing a rough grinding to reduce a thickness of the substrate, before the first grinding processing.
13 . The processing method of claim 11 , further comprising: performing a rough grinding to reduce a thickness of the substrate, before the first grinding processing.
14 . The processing apparatus of claim 7 , wherein a grinding amount of the substrate in the re-grinding processing is equal to a grinding amount of the substrate in the finishing grinding processing.
15 . The processing apparatus of claim 7 , further comprising: a rough grinding device, wherein the controller controls the rough grinding device to perform a rough grinding to reduce a thickness of the substrate, before the first grinding processing.
16 . The processing apparatus of claim 14 , further comprising: a rough grinding device, wherein the controller controls the rough grinding device to perform a rough grinding to reduce a thickness of the substrate, before the first grinding processing.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation application of U.S. patent application Ser. No. 17/904,297, which is a U.S. national phase application under 35 U.S.C. § 371 of PCT Application No. PCT/JP2021/004173 filed on Feb. 4, 2021, which claims the benefit of Japanese Patent Application No. 2020-024474 filed on Feb. 17, 2020, the entire disclosures of which are incorporated herein by reference. TECHNICAL FIELD The various aspects and embodiments described herein pertain generally to a processing method and a processing apparatus. BACKGROUND Patent Document 1 discloses a grinding apparatus for a wafer including a grinding device for the wafer, an inclination adjusting device for adjusting an inclination of a rotation axis of the grinding device, and a grinding condition storage device for storing grinding conditions for the wafer. According to the grinding apparatus described in Patent Document 1, by adjusting the inclination of the rotation axis of the grinding device based on the information stored in the grinding condition storage device, it is attempted to minimize non-uniformity in the thickness of the wafer. PRIOR ART DOCUMENT Patent Document 1: Japanese Patent Laid-open Publication No. 2009-090389 DISCLOSURE OF THE INVENTION Means for Solving the Problems In an exemplary embodiment, a processing method of processing a substrate in a processing apparatus includes performing a first grinding processing on the substrate in a first grinder; performing a second grinding processing on the substrate in a second grinder; performing a first re-grinding processing on the substrate in the first grinder; and performing a second re-grinding processing on the substrate in the second grinder. The substrate is ground to a final thickness in the second re-grinding processing. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram illustrating an example structure of a combined wafer. FIG. 2 is a plan view schematically illustrating an example configuration of a processing apparatus. FIG. 3 is a side view illustrating an example configuration of each grinding unit. FIG. 4A to FIG. 4E are explanatory diagrams illustrating an example of main processes of a processing. FIG. 5 is a flowchart illustrating an example of the main processes of the processing. FIG. 6 is an explanatory diagram schematically illustrating deterioration of a TTV of a first wafer. FIG. 7 is a flowchart illustrating individual processes of a processing of a second sheet of combined wafer onwards. FIG. 8A to FIG. 8D are tables showing a relationship between a grinding amount of the first wafer and a TTV after finishing grinding. DETAILED DESCRIPTION Recently, in a manufacturing process for a semiconductor device, in a combined substrate in which a semiconductor substrate having a plurality of devices such as electronic circuits formed on a front surface thereof (hereinafter, referred to as “first substrate”) and a second substrate are bonded to each other, the first substrate is thinned by grinding a rear surface thereof. The thinning of this first substrate is performed by bringing a grinding whetstone into contact with the rear surface of the first substrate while holding a rear surface of the second substrate with a substrate holder. However, when performing the grinding of the first substrate in this way, the degree of flatness (TTV: Total Thickness Variation) of the first substrate after being ground may be degraded due to the relative inclination between the grinding whetstone in contact with the rear surface of the first substrate and a substrate holding surface holding the second substrate. To be specific, when the processing apparatus temporarily enters a standby state to replace the grinding whetstone for grinding the first substrate, or when a grinding condition in the processing apparatus is changed, the parallelism between the grinding whetstone and the substrate holding surface changes due to changes in device characteristics or environmental characteristics (for example, a change in a device temperature or an atmosphere temperature, a change in a surface state of the grinding whetstone, etc.) before and after the standby of the processing apparatus or before and after the change of the grinding condition. As a result, when a grinding processing immediately after returning from the standby state is performed under the same conditions as the grinding processing before the standby, there is a risk that the TTV of the first substrate may be deteriorated because of the change in the parallelism between the grinding whetstone and the substrate holding surface. The processing method disclosed in Patent Document 1 described above uses the grinding apparatus configured to grinding the first substrate (wafer) to a uniform thickness by adjusting the inclination of the rotation shaft of the grinding whetstone (grinding device). In Patent Document 1, however, nothing is mentioned about considering the devi