Search

CN-122003109-A - Wet etching method and apparatus

CN122003109ACN 122003109 ACN122003109 ACN 122003109ACN-122003109-A

Abstract

The present disclosure provides a wet etching method and apparatus, which belongs to the technical field of semiconductor chip manufacturing. The wet etching method comprises the steps of forming a metal layer on the surface of a wafer, and controlling the wafer to reciprocate at a first position and a second position until etching operation of the metal layer is completed, wherein the wafer is immersed into etching solution of an etching tank when being positioned at the first position, and the wafer is positioned outside the etching solution of the etching tank when being positioned at the second position. The method can improve the problem of inconsistent metal corrosion rates and improve the pattern corrosion precision of the metal layer.

Inventors

  • ZHANG LINLIN
  • CHEN KAI
  • WANG JUNNAN
  • ZHANG SHAOHUA
  • AO LONGHUI

Assignees

  • 京东方华灿光电(浙江)有限公司

Dates

Publication Date
20260508
Application Date
20251217

Claims (10)

  1. 1. A wet etching method, characterized in that the wet etching method comprises: Forming a metal layer on the surface of the wafer; and controlling the wafer to reciprocate at a first position and a second position until the corrosion operation of the metal layer is completed, wherein the wafer invades into the corrosion solution of the corrosion groove when being positioned at the first position, and the wafer is positioned outside the corrosion solution of the corrosion groove when being positioned at the second position.
  2. 2. The wet etching method of claim 1, wherein controlling the wafer to reciprocate between the first position and the second position comprises: and controlling the frequency of the reciprocating movement of the wafer at the first position and the second position to be greater than or equal to 20hz.
  3. 3. The wet etching method of claim 1, wherein controlling the wafer to reciprocate between the first position and the second position further comprises: The temperature of the etching solution in the etching tank is controlled to be 20-30 ℃, and the circulating flow of the etching solution injected into the etching tank is controlled to be 8-12L/Min.
  4. 4. The wet etching method of claim 1, wherein controlling the wafer to reciprocate between the first position and the second position comprises: when the wafer is controlled to move to the first position, the depth of the wafer immersed in the corrosion groove is greater than or equal to 10cm; And when the wafer is controlled to move to the second position, the distance from the wafer to the liquid surface of the corrosion groove is more than or equal to 10cm.
  5. 5. The wet etching method according to any one of claims 1 to 4, wherein the etching rate of the metal layer is 1400 a/min or more and the uniformity of the etching rate of the metal layer is 3.6% or more.
  6. 6. The wet etching device is characterized by comprising an etching tank (10), a carrier (20) and a driving piece (30), wherein an etching solution is contained in the etching tank (10), and the carrier (20) is used for installing a wafer (50); The driving piece (30) is used for controlling the carrier (20) to reciprocate between a first position and a second position until corrosion operation is completed, when the carrier (20) is positioned at the first position, the carrier (20) invades into a corrosion solution of the corrosion tank (10), and when the carrier (20) is positioned at the second position, the carrier (20) is positioned outside the corrosion solution of the corrosion tank (10).
  7. 7. Wet etching apparatus according to claim 6, wherein the drive member (30) is further adapted to control the carrier (20) to reciprocate between the first position and the second position at a frequency of greater than or equal to 20 hz.
  8. 8. Wet etching apparatus according to claim 6 or 7, further comprising a temperature sensor (41), a heating element (42) and a controller (40), the controller (40) being electrically connected to the temperature sensor (41) and the heating element (42), respectively, the temperature sensor (41) being adapted to detect the temperature of the solution in the etching tank (10); the controller (40) is used for acquiring the detection temperature of the temperature sensor (41) in real time, and controlling the heating piece (42) to heat or stop heating the corrosion solution in the corrosion tank (10) based on the detection temperature, so that the temperature of the corrosion solution in the corrosion tank (10) is maintained at 20-30 ℃.
  9. 9. The wet etching apparatus according to claim 8, further comprising an electric pump (43), wherein the controller (40) is electrically connected to the electric pump (43), and wherein the controller (40) is configured to control the electric pump (43) to inject the etching solution into the etching tank (10) at a circulation flow rate of 8L/Min to 12L/Min.
  10. 10. Wet etching apparatus according to claim 8, wherein the driving member (30) comprises a manipulator which grips the carrier (20) to a depth of greater than or equal to 10cm into the etching tank (10), moving the carrier (20) to the first position; the manipulator grabs the carrier (20) to be greater than or equal to 10cm away from the liquid surface of the corrosion groove (10), so that the carrier (20) moves to the second position.

Description

Wet etching method and apparatus Technical Field The present disclosure relates to the field of semiconductor chip manufacturing technologies, and in particular, to a wet etching method and apparatus. Background Trench metal etching is a common wet process in the fabrication of semiconductor devices. The groove type metal corrosion is characterized in that a wafer is immersed in a groove body containing chemical agents, metal is selectively removed through chemical reaction, fine pattern transfer and structure forming are realized, and the groove type metal corrosion is a key wet method step in a semiconductor metal interconnection process. In the related art, the wafer is immersed in a tank body containing a corrosive liquid, and the contact between the liquid medicine and the wafer is realized by static or simple stirring. However, as the reaction proceeds, the reactants in the tank are gradually consumed and byproducts are continuously accumulated, resulting in uneven composition of the liquid medicine at different locations in the tank, thereby making the corrosion rates inconsistent. Further, the liquid density is changed due to the difference in the temperature of the chemical solution or the gas generated by the chemical reaction, and a slight liquid flow is caused. However, the flow is usually weak, and is insufficient to enable the fresh liquid medicine to continuously and uniformly contact all parts of the wafer, so that the problem that local reactants cannot be timely replenished after being consumed is easily caused, and the metal corrosion rate is uneven, thereby affecting the pattern accuracy. Disclosure of Invention The embodiment of the disclosure provides a wet etching method and a wet etching device, which can improve the problem of inconsistent metal etching rate and improve the pattern etching precision of a metal layer. The technical scheme is as follows: On one hand, the embodiment of the disclosure provides a wet etching method, which comprises the steps of forming a metal layer on the surface of a wafer, and controlling the wafer to reciprocate at a first position and a second position until the etching operation of the metal layer is completed, wherein the wafer is immersed into an etching solution of an etching tank when being positioned at the first position, and the wafer is positioned outside the etching solution of the etching tank when being positioned at the second position. In one implementation of the disclosed embodiments, controlling the wafer to reciprocate in the first position and the second position includes controlling a frequency of the wafer to reciprocate in the first position and the second position to be greater than or equal to 20hz. In another implementation mode of the embodiment of the disclosure, when the wafer is controlled to reciprocate at the first position and the second position, the method further comprises the step of controlling the temperature of the etching solution in the etching tank to be 20-30 ℃ and controlling the circulation flow of the etching solution injected into the etching tank to be 8-12L/Min. In another implementation manner of the embodiment of the disclosure, controlling the wafer to reciprocate between a first position and a second position includes controlling the depth of the wafer immersed in the etching tank to be greater than or equal to 10cm when the wafer is moved to the first position, and controlling the liquid level distance from the wafer to the etching tank to be greater than or equal to 10cm when the wafer is moved to the second position. In another implementation of the disclosed embodiments, the metal layer has an etch rate greater than or equal to 1400 a/min and a uniformity of the etch rate of the metal layer greater than or equal to 3.6%. On the other hand, the embodiment of the disclosure provides a wet etching device, which comprises an etching tank, a carrier and a driving piece, wherein an etching solution is filled in the etching tank, the carrier is used for mounting a wafer, the driving piece is used for controlling the carrier to reciprocate at a first position and a second position until etching operation is completed, when the carrier is positioned at the first position, the carrier invades into the etching solution in the etching tank, and when the carrier is positioned at the second position, the carrier is positioned outside the etching solution in the etching tank. In another implementation of an embodiment of the present disclosure, the drive is further configured to control the carrier to reciprocate between the first position and the second position at a frequency of greater than or equal to 20 hz. In another implementation manner of the embodiment of the disclosure, the wet etching device further comprises a temperature sensor, a heating element and a controller, wherein the controller is respectively and electrically connected with the temperature sensor and the heating element, the temperatu