Method and apparatus for uniformly metallization on substrate

Patent metadata

Field	Value
Publication number	US-11629425-B2
Application number	US-202117164539-A
Country	US
Kind code	B2
Filing date	Feb 1, 2021
Priority date	Apr 22, 2013
Publication date	Apr 18, 2023
Grant date	Apr 18, 2023

Abstract

The present invention relates to applying at least one ultra/mega sonic device and its reflection plate for forming standing wave in a metallization apparatus to achieve highly uniform metallic film deposition at a rate far greater than conventional film growth rate in electrolyte. In the present invention, the substrate is dynamically controlled so that the position of the substrate passing through the entire acoustic field with different power intensity in each motion cycle. This method guarantees each location of the substrate to receive the same amount of total sonic energy dose over the interval of the process time, and to accumulatively grow a uniform deposition thickness at a rapid rate.

First claim

What is claimed is:

1. An apparatus for substrate metallization from electrodeless electrolyte comprising:
an immersion bath containing metal salt electrolyte;
a substrate holder for holding at least one substrate;
at least one sonic device coupled with a reflection plate for forming an ultra or mega sonic standing wave area in the immersion bath;
a first oscillating actuator configured for oscillating the substrate holder along its axis for making the substrate holder pass through the entire ultra or mega sonic standing wave area, so as to result in a uniform power intensity distribution across the substrate held by the substrate holder over an accumulated time;
an adjusting mechanism includes an actuator for oscillating the reflection plate or the ultra or mega sonic device along the propagating direction of the ultra or mega sonic standing wave, wherein the oscillation amplitude is equal to N times of half wave length of the ultra or mega sonic standing wave, and N is an integer number from 1 to 10.

2. The apparatus of claim 1 , wherein the first oscillating actuator is configured to oscillate the substrate holder up and down along the axis perpendicular to propagation direction of the ultra or mega sonic standing wave.

3. The apparatus of claim 1 , wherein the first oscillating actuator is configured to oscillate the substrate holder up and down along the axis tilted from an axis which is perpendicular to a propagation direction of the ultra or mega sonic standing wave.

4. The apparatus of claim 1 , further comprising a rotating actuator configured for rotating the substrate holder.

5. The apparatus of claim 1 , further comprising a second oscillating actuator configured for oscillating the substrate holder along a propagation direction of the ultra or mega sonic standing wave, a frequency of the second oscillating actuator being larger than that of the first oscillating actuator while the substrate is passing through the standing wave area.

6. The apparatus of claim 1 , wherein the first oscillating actuator is configured to have an oscillating frequency in the range from 0.001 to 0.5 Hz.

7. The apparatus of claim 1 , wherein the sonic device is configured to operate at a frequency from 20 KHz to 10 MHz with a power intensity from 0.01 to 3 W/cm 2 .

8. The apparatus of claim 1 , wherein the reflection plate is facing to and parallel to the sonic device.

9. The apparatus of claim 1 , wherein the sonic device and the reflection plate are set on the opposite side walls of the immersion bath, with both surfaces thereof immersed in the immersion bath.

10. The apparatus of claim 1 , wherein the reflection plate includes at least two solid plates and an air gap between adjacent two solid plates thereof for minimizing the acoustic energy lost.

11. A method for substrate metallization from electrolyte using the apparatus of claim 1 , the method comprising:
flowing the metal salt electrolyte into the immersion bath;
transferring at least one substrate to the substrate holder;
turning on the ultra or mega sonic device;
oscillating the substrate holder along its axis for making the substrate holder pass through the entire acoustic area;
periodically changing the distance of space between the surfaces of the ultra or mega sonic device and a reflection plate, wherein the distance of space between the surfaces of the ultra or mega sonic device and the reflection plate changes periodically with an amplitude is equal to N times a half wave length of the ultra or mega sonic wave, and N is an integer number from 1 to 10;
stopping the ultra or mega sonic device, the oscillation of the substrate holder, and the periodically changing of said space distance; and
bringing the substrate out of the metal salt electrolyte.

12. The method of claim 11 , wherein
the ultra or mega sonic device has an operating frequency of 20 KHz to 10 MHz and a power intensity of 0.01 to 3 W/cm 2 ; and
the substrate holder oscillates with an amplitude of 1 mm to 300 mm and a frequency of 0.001 to 0.5 Hz.

13. The method of claim 11 , further comprising flipping the substrate 180° while the substrate is within a non-acoustic area.

14. The method of claim 11 , wherein each point of the substrate passes through the entire acoustic area and the power intensity on each point of the substrate is uniform over the course of process.

15. The method of claim 11 , wherein the amplitude of the substrate oscillation equals to

N
·

λ
4

sin
⁢

θ

,

where N=an integer, λ is the wavelength of the ultra or mega sonic wave, and θ is the angle of the sonic device to the side wall of the immersion bath.

16. The method of claim 11 , wherein the frequency of the space distance changing periodically is larger than a frequency of the substrate oscillation.

17. The method of claim 11 , wherein the substrate is oscillated horizontally along a propagating direction of the standing wave while the substrate is oscillated vertically passing through the acoustic area.

18. The method of claim 17 , wherein the amplitude of the horizontal oscillation is controlled as integral times of a quarter wavelength of the ultra or mega sonic wave.

19. The method of claim 11 , wherein the substrate rotates with a speed in a range of 10 rpm to 300 rpm while the substrate is oscillating up and down.

Assignees

• Acm Research Shanghai Inc

Inventors

• Wang Hui
• Chen Fuping
• Wang Xi

Classifications

• C25D17/001

  Apparatus specially adapted for electrolytic coating of wafers, e.g. semiconductors or solar cells · CPC title

• C25D3/02

  from solutions (C25D5/34 - C25D5/46 take precedence) · CPC title

• C25D17/06

  Suspending or supporting devices for articles to be coated · CPC title

• C25D5/18 Primary

  Electroplating using modulated, pulsed or reversing current · CPC title

• C25D5/20

  Electroplating using ultrasonic waves · CPC title