# US 6,295,999 B1 · Wafer cleaning method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,295,999 B1 - Document ID: US6295999B1 - Status: Granted - Kind: B1 - Application number: 09/643,328 - Filed: 2000-08-22 - Granted: 2001-10-02 - Earliest claimed: 1996-09-30 - Assignees: Verteq, Inc. - Inventors: Mario E. Bran - Web page: https://patentgrep.com/patent/US6295999B1 ## CPC - B08B 17/02: Preventing deposition of fouling or of dust - H10P 70/00: Cleaning of wafers, substrates or parts of devices - B06B 3/00: Methods or apparatus specially adapted for transmitting mechanical vibrations of infrasonic, sonic, or ultrasonic frequency - B08B 3/12: by sonic or ultrasonic vibrations - H10P 72/0414: {using mainly spraying means, e.g. nozzles} - H10P 72/0416: {with the semiconductor substrates being dipped in baths or vessels} - Y10S 134/902: Semiconductor wafer - B08B: CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - B06B: METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, {e.g.} FOR PERFORMING MECHANICAL WORK IN GENERAL (for particular applications, see the relevant subclasses, e.g. B07B1/40, B23Q17/12, B24B31/06; measurement of mechanical vibrations G01H; in direction finding, locating, distance or velocity measuring G01S; {generating seismic energy G01V1/02}; control of mechanical vibrations in general G05D; sound-producing devices, e.g. bells, sirens, whistles G10K, {e.g. methods or devices for transmitting, conducting, or directing sound in general G10K11/00}; generation of electrical oscillations H03B; electromechanical resonators in general H03H; electromechanical transducers {for communication techniques, e.g. microphones, speakers} H04R) - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract Semiconductor wafers are cleaned using megasonic energy to agitate cleaning fluid applied to the wafer. A source of energy vibrates an elongated probe which transmits the acoustic energy into the fluid. The probe has a solid cleaning rod and a flared or stepped rear base. In one form, the probe is made of one piece, and in another, the rod fits into a socket in the base. This enables a rod to be made of material which is compatible with the cleaning solution, while the base may be of a different material. A heat transfer member acoustically coupled to the probe base and to a transducer conducts heat away from the transducer. A housing for the heat transfer member and the transducer supports those components and provides means for conducting coolant through the housing to control the temperature of the transducer. In another arrangement, an end of the housing is coupled between the transducer and the probe. In one arrangement, fluid is sprayed onto both sides of a wafer while a probe is positioned close to an upper side. In another arrangement, a short probe is positioned with its end face close to the surface of a wafer, and the probe is moved over the wafer as it rotates. The probe may also be positioned through a central hole in a plurality of discs to clean a group of such elements at one time. ## Claims ### Claim 1 A method of cleaning an article comprising the steps of: positioning the article to be cleaned on a support; placing an elongated side of a rod-like probe spaced from but sufficiently close to a substantially flat surface of said article to loosen particles on the surface when said probe vibrates; introducing fluid into a small gap between the probe and said surface to create a meniscus of fluid between the probe and said surface; vibrating said probe; and producing relative movement between said article and said probe to cause the surface of said article to be cleaned to be sufficiently close to said probe to loosen particles on the surface of said article. ### Claim 2 (depends on 1) The method of claim 1, wherein said probe is vibrated by energizing a transducer connected to said probe to oscillate at a predetermined frequency. ### Claim 3 (depends on 2) The method of claim 2, further comprising the step of controlling temperature of said transducer by conducting coolant in heat transfer relation with the probe. ### Claim 4 (depends on 3) The method of claim 3, including controlling said temperature by positioning a heat transfer member between the probe and the transducer, and conducting coolant in contact with the heat transfer member. ### Claim 5 (depends on 2) The method of claim 2, wherein said energizing is performed at megasonic frequencies. ### Claim 6 (depends on 1) The method of claim 1, wherein said fluid introducing step includes spraying dry ice snow on the wafer. ### Claim 7 (depends on 1) The method of claim 1, wherein the steps performed on said article are performed on a semiconductor wafer. ### Claim 8 (depends on 1) The method of claim 1, wherein said vibrating step is performed at megasonic frequencies. ### Claim 9 A method of cleaning one or more thin disks, comprising: positioning said disks in a container in a substantially vertical orientation with a central opening in each of said disks being horizontally aligned to define a substantially horizontal axis; inserting an elongated rod-like probe through a wall of said container into said disk openings, said rod being adapted to transmit megasonic energy into liquid within the container; and applying megasonic energy to a rear portion of said probe in a manner to cause the probe to vibrate and propagate megasonic energy within the liquid in the container so as to loosen particles on said disks. ### Claim 10 A method of cleaning a semiconductor wafer comprising: supporting the wafer substantially horizontally; positioning a probe close to an upper surface of the wafer; spraying cleaning fluid onto the upper surface and a lower surface of the wafer so that a fluid coupling is formed between the probe and the upper surface of the wafer; and applying megasonic energy to vibrate the probe and loosen particles on the upper and lower wafer surfaces. ### Claim 11 (depends on 10) The method of claim 10, wherein the spraying on the wafer lower surface is approximately aligned with a wafer portion beneath the probe. ### Claim 12 (depends on 10) The method of claim 10, including producing relative movement between the wafer and the probe so that a portion of the upper surface of the wafer to be cleaned is close to the probe. ### Claim 13 A method of cleaning a semiconductor wafer comprising: supporting the wafer substantially horizontally; positioning a probe close to an upper surface of the wafer; introducing cleaning fluid onto the upper surface and a lower surface of the wafer so that a fluid coupling is formed between the probe and the upper surface of the wafer; and applying megasonic energy to vibrate the probe and loosen particles on the upper and lower wafer surfaces.