JPS6058577B2 - How to fix hard mask - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hard mask for forming various element patterns in the manufacture of semiconductor devices.

Emulsion masks have been used for a long time as masks for forming element patterns of semiconductor devices, but in recent years there has been a trend toward the use of hard masks that have increased durability for printing onto semiconductor wafers.

Known materials for hard masks include chrome masks, chromium oxide masks, iron oxide masks, silicon masks, and silicon germanium masks. These hard mask materials are patterned by an exposure method using a positive photoresist, but if the mask has defects such as pinholes of 1 to several microns, the accuracy of the circuit element pattern will be impaired. Therefore, it becomes necessary to correct pinholes in the hard mask. According to traditional hardmask repair methods, if a defect is found by inspecting the hardmask under a microscope,
A positive resist is applied to a hard mask, spot exposure is performed with an ultraviolet beam to remove the negative resist in defective areas, and then metal is deposited or sputtered over the entire hard mask to fill in defective areas such as pinholes. However, according to this method, vapor deposition or sputtering requires a relatively long time, resulting in an increase in the cost of the mask itself.

Furthermore, since the sputtered or vapor-deposited metal is applied not only to the pinholes but also to the entire mask, there is a drawback that the sputtered or vapor-deposited metal film remains in unnecessary areas. The present invention has been made in order to eliminate the drawbacks of the hard mask defect repair method as described above. Pinholes are repaired or corrected by fusing low melting point metal powder with laser light.

According to the present invention, since pinholes are corrected by applying metal powder or the like, there is an advantage that time-consuming processes such as vapor deposition sputtering can be omitted and pinholes can be corrected in a single time. As the low melting point metal, it is preferable to use aluminum, lead, tin, zinc, or an alloy containing these metals. As a method for applying the metal powder, it is preferable to spray it on the entire hard mask or only in the vicinity of the pinholes by an appropriate method. The particle size of the low melting point metal powder is not particularly limited as long as it can be obtained by a metal powdering method such as a spraying method.

The specific method for applying the low melting point metal powder is to apply a negative resist, expose it to ultraviolet light, and then remove the resist using a NaOH solution, etc., as was done in the conventional sputtering correction method. Good too.

As mentioned above, lead, tin, zinc, aluminum, and alloys containing these can be used as low melting point metals, but chemical resistance, especially sulfuric acid resistance, which is one of the properties required for hard masks, must be taken into consideration. Lead or its alloys are then advantageous.

As is clear from the above description, according to the present invention, defects in a hard mask can be repaired without using evaporation or sputtering, thereby reducing the manufacturing time and cost of the hard mask.

Claims (1)

[Claims] 1 Applying a low melting point metal powder onto a hard mask, and irradiating the low melting point metal powder on the portion of the hard mask where the pinhole is located with a laser beam to fuse the low melting point metal powder. Features a hard mask correction method.