JPS5828739A - Radiation sensitive resist - Google Patents

Abstract

PURPOSE:To prevent the adhesion of photomasks to each other and that of a photomask to a water by introducing a compound or groups releasing gaseous nitrogen into a radiation sensitive resist having a reaction mechanism in which gaseous hydrogen is not released. CONSTITUTION:A compound or groups releasing gaseous nitrogen on being irradiated such as naphthoquinone diazide, a diazonium compound or bisdiazide are introduced into a radiation sensitive resist releasing no gaseous nitrogen on being irradiated to allow the resist to release gaseous nitrogen on being irradiated. The resist is a radiation sensitive resist causing a mol.wt. decreasing reaction by the cutting of the principal chain in the reaction mechanism on being irradiated, e.g., a radiation sensitive resist made chiefly of polymethyl isopropenyl ketone, a radiation sensitive resist causing a mol.wt. increasing reaction by the opening of the double bonds on being irradiated, or a radiation sensitive resist causing a cross-linking reaction by the ring opening of the epoxy groups on being irradiated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a radiation-sensitive resist exhibiting high photosensitivity and high contrast characteristics to radiation applied in the manufacturing process of semiconductor devices and integrated circuits, and particularly relates to a photomask-photomask generated during contact exposure. Mask or photomask
This invention relates to a radiation-sensitive resist that can prevent wafers from coming into close contact.

In photophosphorography, in order to form a pattern on a semiconductor substrate, radiation #! A commonly used method is to irradiate. Currently, the method widely used in this process is the so-called contact exposure method, which involves directly contacting the semiconductor substrate completely coated with photoresist with a photomask.
This is a method of burning a pattern. According to this method,
It is possible to transfer highly accurate patterns with high resolution. On the other hand, the semiconductor substrate fully coated with photoresist and the photomask may stick together and cannot be separated, causing work to stop, or the photoresist on the semiconductor substrate may be deposited on the photomask and removed, resulting in defects. There were problems such as a decrease in product yield. A similar phenomenon also occurred when creating a photomask. When creating a complete photomask, as is well known, an original plate called a master mask with a predetermined pattern is created, and this is used as a mask substrate coated with photoresist (
Usually chrome on a glass substrate.

However, in this case as well, the above-mentioned phenomenon of adhesion occurs, which has been a problem.

On the other hand, this drawback is caused by radiation-sensitive resists having a diazo group as a photosensitive group, such as the product name A.
When using Z-1350J (manufactured by Sibley, USA),
Rubber-based radiation sensitive resist, such as product name OMR-8
It is known that this phenomenon is less likely to occur when bisazide is used as a crosslinking material, such as in No. 3 (manufactured by Tokyo Ohka Co., Ltd.).

This is because the photosensitive group has a reaction mechanism that releases nitrogen gas when irradiated with radiation.

On the other hand, the reaction mechanism during radiation irradiation of radiation-sensitive resists is a lower molecular weight reaction due to main chain scission, a higher molecular weight reaction due to double bond dissociation, or a crosslinking reaction due to ring opening of epoxy groups. As in the case where
A reaction mechanism that does not release all nitrogen gas is likely to cause the above-mentioned problems.

The present invention focuses on this point and provides a method for eliminating the above-mentioned disadvantages by improving conventional radiation-sensitive resists that do not release all nitrogen gas during radiation irradiation.

That is, the present invention relates to a radiation-sensitive resist, which is characterized in that a compound or foundation that releases nitrogen gas when irradiated with radiation is introduced into a radiation-sensitive resist that does not release nitrogen gas when irradiated with radiation.

Hereinafter, the present invention will be explained in detail with reference to Examples.

Wavelength 200nm ~ 35Q as radiation sensitive resist
Resist with absorption gold near nm, product name 0DtJR-1
013 (manufactured by Tokyo Ohka Co., Ltd.) were all used. The main component of this radiation-sensitive resist is polymethyl isopropenyl ketone, and when it is fully irradiated with radiation of the above-mentioned wavelength, it stimulates a main chain scission reaction, resulting in a lower molecular weight, and the irradiated portion becomes soluble in a developer. Naphthoquinonediazide is dissolved in this resist material in a range of several molar units to several tens of molar units, preferably in a range of 5 molar units to 20 molar units. In this case, a solvent is naturally selected that completely dissolves both polymethyl isopropenyl ketone and naphthoquinonediazide. The spectral sensitivity of naphthoquinonediazide is around 250 to 5QQnm. This radiation sensitive resist material is applied onto the mask substrate by a suitable method such as spin coating. Next, the master mask patterned in predetermined portions and the mask substrate were subjected to contact exposure using a contact printer, trade name M155 (manufactured by Tamarack, Inc., USA).

According to this method, it was possible to reduce the development of adhesion between photomasks that occurred when contact exposure was performed at 0 DUR, -1013.

In this example, the close exposure between photomasks was described, but similar results were obtained in the close exposure between a photomask and a wafer.

Furthermore, although naphthoquinonediazide has been described as a material that releases nitrogen gas during irradiation, this method can also be applied to other compounds that release nitrogen gas during irradiation, such as diazonium compounds and bisdiazide. Needless to say.

5- Furthermore, if the spectral sensitivities of the radiation-sensitive resist and the compound that releases nitrogen gas are different, first expose in the sensitive wavelength range of the radiation-sensitive resist, and then expose in the sensitive wavelength range of the compound that releases all nitrogen gas. good.

As described above, according to the present invention, adhesion between a photomask and a photomask and between a photomask and a wafer is prevented, so workability is significantly improved, and photoresist bumps are prevented from missing. Product yield can be improved.

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Claims (1)

[Claims] A radiation-sensitive resist characterized in that a compound or group that releases nitrogen gas when irradiated with radiation is introduced into a radiation-sensitive resist that does not release nitrogen gas when irradiated with radiation.