Inspection apparatus and method of inspecting wafer

Patent metadata

Field	Value
Publication number	US-12196669-B2
Application number	US-202217882673-A
Country	US
Kind code	B2
Filing date	Aug 8, 2022
Priority date	Dec 27, 2021
Publication date	Jan 14, 2025
Grant date	Jan 14, 2025

Abstract

An inspection apparatus includes: a first probe including a receiver antenna configured to detect the terahertz wave emitted by an inspection signal source and that has passed through the wafer, wherein the first probe includes: a first probe tip in which the receiver antenna is embedded, the receiver antenna including a first photoconductive switch; a first printed circuit board on which the first probe tip is mounted; a first optical bracket coupled to the first printed circuit board; a first optical connector configured to transmit a first laser beam into the first probe, and coupled to the first optical bracket, wherein the first laser beam is configured to excite the first photoconductive switch.

First claim

What is claimed is:

1. An inspection apparatus comprising:
a stage configured to support a wafer;
an inspection signal source facing the stage, and configured to emit a terahertz wave to the wafer;
a first probe including a receiver antenna configured to detect the terahertz wave emitted by the inspection signal source and that has passed through the wafer; and
a second probe including an emitter antenna and a detector antenna, wherein the emitter antenna is configured to emit a terahertz wave to the wafer, and the detector antenna is configured to detect the terahertz wave emitted by the emitter antenna and reflected by the wafer,
wherein the first probe includes:
a first probe tip in which the receiver antenna is embedded, the receiver antenna including a first photoconductive switch;
a first printed circuit board on which the first probe tip is mounted;
a first optical bracket coupled to the first printed circuit board;
a first optical connector configured to transmit a first laser beam into the first probe, and coupled to the first optical bracket, wherein the first laser beam is configured to excite the first photoconductive switch;
a first optical cable connected to the first optical connector, arranged between the first optical bracket and the first printed circuit board, and configured to guide the first laser beam;
a first lens connected to the first optical cable, fixed to the first optical bracket, and configured to focus the first laser beam; and
a first mirror fixed to the first optical bracket and configured to reflect the first laser beam received from the first lens so that the first laser beam is directed toward the first photoconductive switch.

2. The inspection apparatus of claim 1 , wherein an air gap is arranged between the first mirror and the first photoconductive switch.

3. The inspection apparatus of claim 1 , wherein the first probe further includes:
a second optical connector configured to transmit a second laser beam into the first probe, and coupled to the first optical bracket, wherein the second laser beam is configured to excite the wafer;
a second optical cable connected to the second optical connector, arranged between the first optical bracket and the first printed circuit board, and configured to guide the second laser beam; and
a second mirror configured to reflect the second laser beam so that the second laser beam is directed toward the wafer.

4. The inspection apparatus of claim 3 , wherein the first probe further includes: a second lens arranged on a path of the second laser beam between the second optical cable and the second mirror;
a first non-linear optical device arranged on a path of the second laser beam between the second lens and the second mirror; and
a third lens arranged on the path of the second laser beam between the first non-linear optical device and the second mirror.

5. The inspection apparatus of claim 4 , wherein the first non-linear optical device includes a second-order harmonic generator.

6. The inspection apparatus of claim 4 , wherein the first non-linear optical device includes one of periodically poled lithium niobate (PPLN) crystal and beta barium borate (BBO) or β-BaB 2 O 4 crystal.

7. The inspection apparatus of claim 4 , wherein the first non-linear optical device is arranged to receive the second laser beam focused by the second lens.

8. The inspection apparatus of claim 1 , wherein the second probe includes:
a second probe tip in which the emitter antenna and the detector antenna are embedded, the emitter antenna including a second photoconductive switch, and the detector antenna including a third photoconductive switch;
a second primed circuit board on which the second probe tip is mounted;
a second optical bracket coupled to the second printed circuit board;
a third optical connector configured to transmit a third laser beam into the second probe, and coupled to the second optical bracket, wherein the third laser beam is configured to excite the second photoconductive switch;
a third optical cable connected to the third optical connector, arranged between the second optical bracket and the second printed circuit board, and configured to guide the third laser beam;
a fourth lens connected to the third optical cable, fixed to the second optical bracket, and configured to focus the third laser beam; and
a third mirror fixed to the first optical bracket and configured to reflect the third laser beam received from the fourth lens so that the third laser beam is directed toward the second photoconductive switch.

9. The inspection apparatus of claim 8 , wherein the second probe includes:
a fourth optical connector configured to transmit a fourth laser beam into the second probe, and coupled to the second optical bracket, wherein the fourth laser beam is configured to excite the third photoconductive switch;
a fourth optical cable connected to the fourth optical connector, arranged between the second optical bracket and the second printed circuit board, and configured to guide the fourth laser beam;
a fifth lens connected to the fourth optical cable, fixed to the second optical bracket, and configured to focus the fourth laser beam; and
a fourth mirror fixed to the second optical bracket and configured to reflect the fourth laser beam received from the fifth lens so that the fourth laser beam is directed toward the third photoconductive switch.

10. The inspection apparatus of claim 9 , wherein air gaps are respectively arranged between the third mirror and the second photoconductive switch, and between the fourth mirror and the third photoconductive switch.

11. The inspection apparatus of claim 9 , wherein the second probe further includes:
a fifth optical connector configured to transmit a fifth laser beam into the second probe, and coupled to the second optical bracket, wherein the fifth laser beam is configured to excite the water;
a fifth optical cable connected to the fifth optical connector, arranged between the second optical bracket and the second printed circuit board, and configured to guide the fifth laser beam; and
a fifth mirror configured to reflect the fifth laser beam so that the fifth laser beam is directed toward the water.

12. The inspection apparatus of claim 11 , further comprising:
a sixth lens arranged on a path of the fifth laser beam between the fifth optical cable and the fifth mirror;
a second non-linear optical device arranged on a path of the fifth laser beam between the sixth lens and the fifth mirror; and
a seventh lens arranged on the path of the fifth laser beam between the second non-linear optical device and the fifth minor.

13. An inspection apparatus comprising:
a stage including an upper surface parallel to a first direction and a second direction intersecting the first direction, and supporting a wafer;
an inspection signal source configured to emit a terahertz wave on the wafer;
a first probe including a receiver antenna configured to detect the terahertz wave emitted by the inspection signal source and that has passed through the Wafer, and
a second probe including an emitter antenna and a detector antenna, wherein the emitter antenna is configured to emit a terahertz wave to the wafer, and the detector antenna is configured to detect the terahertz wave emitted by the emitter antenna and reflected by the wafer,
wherein the first probe includes:
a first printed circuit board;
a first probe tip, in which the receiver antenna is embedded, mounted on the first printed circuit board, wherein the receiver antenna includes, a first photoconductive switch;
a first optical bracket coupled to the first

Assignees

• Samsung Electronics Co Ltd

Inventors

• Priwisch Martin
• Yoon Jongmin
• Park Suhwan
• Baek Inkeun

Classifications

• G01N21/9501

  Semiconductor wafers (manufacturing processes per se of semiconductor devices implementing a measuring step H10P74/20) · CPC title

• G01Q60/22

  Probes, their manufacture, or their related instrumentation, e.g. holders · CPC title

• G01R31/311

  of integrated circuits {(G01R31/31728 takes precedence)} · CPC title

• G01N2021/3568

  applied to semiconductors, e.g. Silicon · CPC title

• G01N21/3563

  for analysing solids; Preparation of samples therefor · CPC title