JP2005045156A - Lift-off method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lift-off method for stably forming a pattern having substantially no burr and an apparatus therefor, in relation to a lift-off method for a semiconductor substrate, on a surface of which an evaporated metal film to be removed is formed via a resist, and a lift-off apparatus for realizing the method. <P>SOLUTION: An ultrasonic peeling-liquid jet nozzle 2, a peeling-liquid shower jet nozzle 3, and a solvent jet nozzle are provided. The evaporated metal film is physically peeled off by the peeling liquid to which ultrasonic power is superposed on its surface, and metal residuals and the resist are removed by jetting the peeling liquid of a raised temperature in a shower. Then, residuals of the resist are removed by jetting a solvent of a raised temperature in order to prevent residual organic coating films. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a lift-off method for a semiconductor substrate having a vapor-deposited metal film to be removed on a surface via a resist and a lift-off device for realizing the method.

  Conventionally, as a lift-off method and a lift-off device, there has been one as described in Patent Document 1, for example. FIG. 2 shows a schematic diagram of a conventional method and apparatus configuration described in Patent Document 1.

  In FIG. 2, reference numerals 9, 10, and 11 denote batch immersion solvent tanks equipped with ultrasonic waves. A cassette 8 containing a semiconductor substrate on which a vapor-deposited metal film to be removed is formed on a surface is formed on a cassette support 7. After setting, the resist is swollen by dipping in a batch dipping solvent tank 9 for a predetermined time by a well-known transport mechanism. At this time, the ultrasonic vibration can be applied from the ultrasonic transmitter 12 provided in the batch immersion solvent tank 9 as desired.

Since only the solvent tank 9 has poor swelling performance of the resist between the substrate surface and the vapor deposition metal, it is sequentially conveyed to the batch immersion solvent tanks 10 and 11 having the same functions as the batch immersion solvent tank 9 and processed for a predetermined time. , Improve the swelling performance. Thereafter, the semiconductor substrate 1 is transported one by one to the chuck portion 4 of the spin chamber having the vapor deposition metal peeling solvent jet discharge nozzle 13 and the rinsing solvent discharge nozzle 14 by a well-known transport mechanism to hold the semiconductor substrate 1. . Thereafter, the semiconductor substrate 1 is rotated, the solvent given a desired pressure is discharged from the solvent jet discharge nozzle 13 for a predetermined time, and the deposited metal film adhering to the surface of the semiconductor substrate is peeled off. Thereafter, the solvent is discharged from the rinsing solvent discharge nozzle 14 for a predetermined time to clean the surface of the semiconductor substrate, and then spin drying is performed.
JP-A-1-175236 (page 1-8, FIG. 1)

  However, in the conventional configuration, the resist is not sufficiently swelled due to the thickness ratio between the thickness of the resist and the deposited metal film interposed between the surface of the semiconductor substrate 1 and the deposited metal and the variation in each film thickness. In some cases, the film was not evenly peeled and partly remained as burrs.

  As described above, since the ratio between the resist thickness and the deposited metal film thickness is likely to vary within the surface of the semiconductor substrate, it is necessary to sufficiently swell the resist. In addition, if the resist does not swell sufficiently, the resist residue remaining on the surface of the semiconductor substrate during the rinsing process after peeling of the deposited metal is not sufficiently removed, and an organic film is generated and the film is peeled off after film formation in the subsequent process. In some cases, etc.

  The present invention has been made to solve the above-described problems, and provides a lift-off method and apparatus for stably forming a pattern without burrs.

  In order to solve the above-mentioned conventional problems, the automatic lift-off method of the present invention includes a step of discharging a stripping solution in which ultrasonic waves are superposed on the surface and a step of discharging a stripping solution raised to a desired temperature. A means for adjusting the temperature of the liquid, a stripping liquid discharge nozzle provided with ultrasonic waves, and a nozzle for discharging the stripped liquid whose temperature has been raised in a shower form are provided.

  As described above, according to the automatic lift-off device and method of the present invention, it is possible to suppress the occurrence of burrs of the deposited metal after the lift-off. Furthermore, it is possible to prevent the organic film remaining on the surface of the semiconductor substrate after rinsing / drying.

Embodiments of the present invention will be described below with reference to the drawings.
(Embodiment 1)
FIG. 1 is a block diagram of an automatic lift-off device according to Embodiment 1 of the present invention. A semiconductor substrate 1 on which a deposited metal film to be removed through a resist is formed on a spin chuck unit 4 by a well-known transport mechanism. To do. Thereafter, a stripping solution having propagated ultrasonic vibration energy of 0.8 to 1.5 MHz is discharged from the discharge nozzle 2 for a predetermined time onto the semiconductor substrate 1 rotated at 600 to 800 rpm.

  At this time, the discharge nozzle 2 reciprocates on the surface of the semiconductor substrate 1 at a predetermined distance for a predetermined time. Thereafter, a stripping solution having a temperature of 40 to 60 ° C. is ejected from the stripping solution discharge shower nozzle 3 at a pressure of 40 to 60 kgf / cm for a predetermined time to remove the resist residue.

  Thereafter, the semiconductor substrate 1 is held on the chuck portion 4 by being transferred to a rinsing / drying chamber by a known transfer mechanism. Next, a rinsing solvent having a temperature of 40 to 60 ° C. is discharged from the solvent discharge nozzle 6 onto the semiconductor substrate 1 rotated at 1000 to 1500 rpm, and the resist residue and the stripper remaining on the semiconductor substrate 1 are completely removed. Remove.

  Then, it spins and dries for desired time at 2500 rpm. At this time, since the temperature of the solvent is increased, the treatment can be performed in a relatively short time and the occurrence of a solvent film can be prevented.

  The lift-off method of the present invention is useful for suppressing the occurrence of burrs of deposited metal after lift-off.

Configuration schematic diagram of automatic lift-off device in Embodiment 1 of the present invention Schematic diagram of a conventional automatic lift-off device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor substrate 2 Stripping liquid ultrasonic discharge nozzle 3 Stripping liquid shower discharge nozzle 4 Spin chuck part 5 Coupling 6 Solvent discharge nozzle 7 Cassette support stand 8 Cassette 9 Batch immersion solvent tank 10 Batch immersion solvent tank 11 Batch immersion solvent tank 12 Over Sonic wave transmitter 13 Solvent jet discharge nozzle 14 Solvent discharge nozzle

Claims (4)

A step of discharging a stripping solution in which ultrasonic waves are superposed on the surface and a step of discharging a stripping solution raised to a desired temperature while rotating a semiconductor device substrate on which a deposited metal film to be removed is formed via a resist on the surface; A lift-off method characterized by comprising a step of discharging a solvent raised to a desired temperature and a step of performing dry-drying. The lift-off method according to claim 1, wherein the ultrasonic wave superimposed on the discharged stripping solution is 0.8 to 1.5 MHz. The lift-off method according to claim 1, wherein the desired stripping solution temperature is 40 to 60 ° C. and discharging is performed in a shower shape. The lift-off method according to claim 1, wherein the temperature of the rinsing solvent is 40 to 60 ° C.

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