Semiconductor wafer photoelectrochemical mechanical polishing processing device and processing method

Patent metadata

Field	Value
Publication number	US-2022088740-A1
Application number	US-201917413939-A
Country	US
Kind code	A1
Filing date	Dec 13, 2019
Priority date	Dec 14, 2018
Publication date	Mar 24, 2022
Grant date	—

Abstract

A semiconductor wafer is adhered and fixed to a polishing head by means of a conductive adhesive, and the wafer is connected to a positive electrode of an external power supply through wires of the inner and outer rings of a conductive slip ring below the wafer. A polishing pad is adhered to the bottom of a counter electrode disc, the counter electrode disc is fixed at the bottom of a polishing disc and is processed with through holes at the position corresponding to the polishing disc, and the counter electrode disc is connected to a negative electrode of the external power supply through the wires of inner and outer rings of a conductive slip ring above the counter electrode disc. Ultraviolet light emitted by an ultraviolet light source can reach the surface of the wafer through the through holes, and a polishing solution can be sprayed through the through holes into a contact area between the wafer and the polishing pad.

First claim

1 . A semiconductor wafer photoelectrochemical mechanical polishing processing device, comparing:
a polishing pad having through holes; a polishing disc having through holes, driving the polishing pad to mechanically polish a surface of a wafer; a polishing solution source supplying a polishing solution, the polishing solution dripping on the wafer surface through the through holes of the polishing disc and the polishing pad; an ultraviolet light source supplying ultraviolet light, the ultraviolet light irradiating the wafer through the through holes of the polishing disc and the polishing pad; and an external power supply; wherein the wafer is connected to a positive electrode of the external power supply, and the polishing disc is connected to a negative electrode of the external power supply; and the external power supply, the wafer and the polishing disc form a closed circuit.

2 . A semiconductor wafer photoelectrochemical mechanical polishing processing device, comparing:
a polishing pad having through holes; a polishing disc having through holes, driving the polishing pad to mechanically polish a surface of a wafer; a counter electrode disc having through holes, arranged between the polishing disc and the polishing pad; a polishing solution source supplying a polishing solution, the polishing solution dripping on the wafer surface through the through holes of the polishing disc and the polishing pad; an ultraviolet light source supplying ultraviolet light, the ultraviolet light irradiating the wafer through the through holes of the polishing disc and the polishing pad; and an external power supply; wherein the wafer is connected to a positive electrode of the external power supply, and the counter electrode disc is connected to a negative electrode of the external power supply; and the external power supply, the wafer and the counter electrode disc form a closed circuit.

3 . The semiconductor wafer photoelectrochemical mechanical polishing processing device according to claim 1 , wherein the polishing solution is a chemical polishing solution which comprises abrasive particles.

4 . The semiconductor wafer photoelectrochemical mechanical polishing processing device according to claim 1 , wherein the polishing disc and the polishing pad are located above the wafer, and the ultraviolet light source is located above the polishing disc and the polishing pad.

5 . The semiconductor wafer photoelectrochemical mechanical polishing processing device according to claim 1 , wherein the polishing solution source is a polishing solution spray head which is located above the polishing disc.

6 . The semiconductor wafer photoelectrochemical mechanical polishing processing device according to claim 1 , wherein the through holes of the polishing disc are arranged radially from a center of the polishing disc to periphery; preferably, the through holes are arranged periodically along the radial direction of the polishing disc; preferably, a center part of the polishing disc is not provided with through hole, and only a position where the peripheral part of the polishing disc contacts with the wafer is provided with the through holes.

7 . The semiconductor wafer photoelectrochemical mechanical polishing processing device according to claim 1 , wherein layouts of the through holes of the polishing disc, the counter electrode and the polishing pad are consistent.

8 . The semiconductor wafer photoelectrochemical mechanical polishing processing device according to claim 1 , wherein the power supply of the external electric field is at least one of a direct-current power supply, a potentiostat, an electrochemical workstation and a dry battery.

9 . The semiconductor wafer photoelectrochemical mechanical polishing processing device according to claim 1 , wherein an area of the polishing pad is greater than that of the wafer; a preferred radius of the polishing pad is greater than a diameter of the wafer; a preferred radius of the polishing disc is greater than a diameter of the wafer; and preferably, the through holes of the polishing pad are arranged at a portion in contact with the wafer.

10 . The semiconductor wafer photoelectrochemical mechanical polishing processing device according to claim 1 , wherein an area ratio of photoelectrochemical action and mechanical action of the device is 1:12 to1:1.

11 . A semiconductor wafer photoelectrochemical mechanical polishing processing method, mechanically polishing a wafer; mechanically polishing a polishing piece having through holes;
during polishing, ultraviolet light irradiating the wafer through the through holes; during polishing, the polishing solution dripping on the surface of the wafer through the through holes, and the polishing solution comprising abrasive particles; and during polishing, the wafer being used as an anode and being modified by photoelectrochemical oxidation under an external electric field.

12 . The semiconductor wafer photoelectrochemical mechanical polishing processing method according to claim 11 , wherein the polishing piece comprises polishing disc and polishing pad, and the layout of the through holes of the polishing disc is consistent with that of the polishing pad; and the polishing disc is used as a cathode.

13 . The semiconductor wafer photoelectrochemical mechanical polishing processing method according to claim 12 , comprising the following steps:
S 1 . fixing the wafer to a polishing head by means of conductive adhesive, after driving, the wafer rotating axially with the polishing head, wherein the polishing head is an electric conductor; adhering the polishing pad to the polishing disc, after driving, the polishing pad contacting the wafer surface and producing a relative motion; S 2 . applying a positive potential to the wafer and a negative potential to the polishing disc; and S 3 . during polishing, ultraviolet light irradiating the wafer successively passing through the through holes of the polishing disc and the polishing pad; and the polishing solution impregnating a contact area between the wafer and the polishing pad by the through holes of the polishing disc and the polishing pad.

14 . The method according to claim 11 , wherein the polishing piece comprises the polishing disc and the polishing pad, the counter electrode disc having through holes is arranged between the polishing disc and the polishing pad as a cathode; and the layouts of the through holes of the polishing disc, the counter electrode and the polishing pad are consistent.

15 . The method according to claim 14 , comprising the following steps:
S 1 . fixing the wafer to the polishing head by means of conductive adhesive, after driving, the wafer rotating axially with the polishing head, wherein the polishing head is an electric conductor; adhering the polishing pad to the counter electrode disc, and fixing the counter electrode disc to the polishing disc, after driving, the polishing pad contacting the wafer surface and producing a relative motion, wherein the counter electrode disc has through holes; S 2 . applying a positive potential to the wafer and a negative potential to the disc-shaped counter electrode disc; and S 3 . during polishing, ultraviolet light irradiating the wafer successively passing through the through holes of the polishing disc, the counter electrode disc and the polishing pad; and the polishing solution impregnating a contact area between the wafer and the polishing pad by the through holes of the polishing disc, the counter electrode disc and the polishing pad successively.

16 . The method according

Assignees

• Univ Dalian Tech

Inventors

• Dong Zhigang
• Shi Kang
• Kang Renke
• Ou Liwei
• Zhu Xianglong
• Gao Shang

Classifications

• H10P52/402

  of semiconductor materials · CPC title

• H10P90/129

  by polishing · CPC title

• H10D62/8503

  Nitride Group III-V materials, e.g. AlN or GaN · CPC title

• C09G1/02

  containing abrasives or grinding agents {(abrasives as such C09K3/14; polishing of semi-conductors H10P52/40)} · CPC title

• B24B37/10 Primary

  for single side lapping · CPC title