CN111308860B - Negative photoresist composition resistant to strong acid corrosion - Google Patents

Abstract

The invention discloses a negative photoresist composition resistant to strong acid corrosion, which comprises main resin, an acid generator, a cross-linking agent and a solvent; wherein the total solid of the photoresist is taken as a reference, the amount of the main resin accounts for 10-50% of the total solid, the amount of the acid generator accounts for 10-30% of the total solid, the amount of the cross-linking agent accounts for 0.4-5% of the total solid, and the amount of the solvent accounts for 10-55% of the total solid. The negative photoresist composition has good adhesiveness, can bear strong acid corrosive liquid, can realize the substitution of the prior cyclized rubber, does not contain harmful solvents such as dimethylbenzene and the like, adopts weak alkaline aqueous solution for development and deionized water for fixation, has no environmental hidden trouble, greatly improves the production environment, and reduces the production cost.

Description

Negative photoresist composition resistant to strong acid corrosion

Technical Field

The invention relates to a photoresist, in particular to a negative photoresist composition resistant to strong acid corrosion.

Background

With the miniaturization development of electronic components, microelectromechanical systems (MEMS) have become a key technology for manufacturing micro devices such as micromachines, sensors, control circuits, and the like, and integrating the micro devices into chips. Since the integration and fabrication of chips mostly uses silicon as a substrate, a wet etching process of silicon, which is the most basic and critical technique in the processing of silicon substrates, is widely used for processing various microstructures such as a groove structure, a film structure, a cantilever beam, etc. on a silicon substrate, and has been used for the fabrication of many nanostructures in recent years. Among them, the planar etching groove technique is most widely used. The technology is often integrated with a semiconductor plane process, a mesa process and a glass sintering process, photoresist needs to be coated for many times in the process, and the coated photoresist needs to bear the corrosion of strong acid corrosive liquid so as to protect the part of the surface of the silicon substrate without grooves. In the current technology, cyclized rubber negative ultraviolet photoresist is commonly adopted, because other photoresist systems cannot bear the deep corrosion of strong acid corrosive liquid. The cyclized rubber is a cyclized polymer formed by intramolecular cyclization reaction of cyclized polyisoprene and cyclized polybutadiene, has high solubility, film forming property, good heat resistance and higher strength, has good and stable performance in the aspects of adhesion to metal and acid resistance, is widely applied, and occupies a large amount in photoresist.

In the preparation process of cyclized rubber photoresist, xylene solution is generally used for the cyclizing reaction, and xylene can only be used as an organic solvent at present because the cyclized rubber is difficult to dissolve. In addition, the developer and fixing solution used in the photolithography process for the photoresist of the cyclized rubber system are volatile organic solvents having a certain toxicity. Xylene has moderate toxicity and certain carcinogenicity, is easy to volatilize and is absorbed by human body through respiratory tract and skin, can cause acute poisoning symptoms when being inhaled in a high concentration for a short time, can cause neurasthenia syndrome when being contacted for a long time, and can cause reproductive diseases for females. And the solvent volatilized to the high-temperature airtight condition has a certain explosion hazard when the baking is carried out in the baking oven in the photoetching process. Therefore, the preparation and use of cyclized rubber photoresist have been a problem to be solved in industry due to the unavoidable need of contacting toxic organic solvents such as xylene.

Disclosure of Invention

The invention provides a negative photoresist composition resistant to strong acid corrosion, which aims to solve the technical problem that toxic organic solvents such as dimethylbenzene and the like are inevitably required to be contacted in the preparation and use of cyclized rubber photoresist.

In order to solve the technical problems, the technical scheme of the invention is as follows:

a negative photoresist composition resistant to strong acid corrosion comprising: a host resin, an acid generator, a crosslinking agent and a solvent; wherein the main resin accounts for 10-50% of the total solid based on the total solid of the photoresist, the acid generator accounts for 10-30% of the total solid, the cross-linking agent accounts for 0.4-5% of the total solid, the solvent accounts for 10-55% of the total solid, the main resin is phenolic resin, and the molecular weight of the phenolic resin is 1000-10000.

As a preferred embodiment, the crosslinking agent is one or a mixture of more than two of melamine, cyanuric acid derivative, melamine phosphate, melamine derivative modified polyurethane and benzomelamine.

As a preferred embodiment, the acid generator is one or a mixture of two or more of diazonium salt, sulfonium salt, iodonium salt, phosphate, triazine, sulfonate and hexafluoroantimonate.

As a preferred embodiment, the solvent is one or a mixture of more than two of propylene glycol methyl ether, propylene glycol methyl ether acetate, glycol ether, ethylene glycol alkyl ether acetate and diethylene glycol.

A process for photolithography of a negative photoresist composition resistant to strong acid corrosion comprising the steps of:

(1) Mixing the main resin, the acid generator, the cross-linking agent and the solvent in proportion, fully dissolving, and filtering by using a filter membrane with the aperture of 0.2 microns to obtain a photoresist solution;

(2) Spin-coating photoresist prepared from the components on a processed substrate, pre-baking (PAB) by using a hot plate, regulating the rotating speed to ensure that the dried film thickness is a certain thickness, exposing the film thickness through a mask plate by using an exposure machine i line, and recording exposure metering;

(3) And (3) baking in a baking oven at a certain temperature for 30min, soaking and developing for 90s by using 2.38wt% TMAH, cleaning by using deionized water, and baking and hardening by using the baking oven to finish the photoetching process, thereby obtaining the pattern complementary with the shading area of the mask.

The invention adopts the technical scheme that the phenolic aldehyde main resin, the acid generator, the cross-linking agent and the solvent which are reasonably proportioned are adopted, the acid corrosion resistance and the chemical stability are good after the exposure reaction, the substitution of the prior cyclized rubber can be realized, the prior cyclized rubber does not contain harmful solvents such as dimethylbenzene and the like, and the aqueous solution with weak alkalinity is adopted for development and deionized water fixation, so that the invention has no environmental hidden trouble, greatly improves the production environment and reduces the production cost.

Detailed Description

The following is a further description of embodiments of the invention, in conjunction with examples. The description of these embodiments is provided to assist understanding of the present invention, but is not intended to limit the present invention. In addition, the technical features of the embodiments of the present invention described below may be combined with each other as long as they do not collide with each other.

Example 1

A negative photoresist composition resistant to strong acid corrosion having the composition shown in table one;

table one: component of strong acid corrosion resistant negative photoresist composition I

Phenolic resin	100g
		Melamine	2.0g
Triphenylhexafluoroantimonate	50g
		Propylene glycol methyl ether	100g

A process for photolithography of a negative photoresist composition resistant to strong acid corrosion comprising the steps of:

(1) Mixing phenolic resin, melamine, triphenyl hexafluoroantimonate and propylene glycol methyl ether in proportion, fully dissolving, and filtering with a filter membrane with the aperture of 0.2 microns to obtain a photoresist solution;

(2) Spin-coating photoresist prepared from the components on a processed substrate, pre-baking (PAB) the photoresist by using a hot plate at 100 ℃/120s, regulating the rotating speed to ensure that the dried film thickness is 10 mu m, exposing the photoresist through a mask plate by using an exposure machine i-line, and measuring the exposure to be 100mJ/cm < 2 >;

(3) And (3) baking in a baking oven at 100 ℃ for 30min, soaking and developing for 90s by using 2.38wt% TMAH, cleaning by using deionized water, and then baking and hardening by the baking oven for 130 ℃/30min to finish the photoetching process, thereby obtaining the pattern complementary with the shading area of the mask.

Detection index

Adhesion properties	3 grade
		Acid and alkali resistance	Preferably, it is
Sensitivity to	100mJ/cm2

Example two

A negative photoresist composition resistant to strong acid corrosion, the composition of which is shown in table two below;

and (II) table: component of negative photoresist composition II resistant to strong acid corrosion

Phenolic resin	50g
		Benzomelamine	0.5g
Diphenyl p-benzylidene triflate	20g
		Propionic acid and propan-twoMethyl alcohol acetate	47g

A process for photolithography of a negative photoresist composition resistant to strong acid corrosion comprising the steps of:

(1) Mixing phenolic resin, benzoguanamine, diphenyl p-benzylidene trifluoro methane sulfonate and propylene glycol methyl ether acetate according to a proportion, fully dissolving, and filtering by using a filter membrane with the aperture of 0.2 microns to obtain a photoresist solution;

(2) Spin-coating photoresist prepared from the components on a processed substrate, pre-baking (PAB) the photoresist by using a hot plate at 100 ℃/90s, regulating the rotating speed to ensure that the dried film thickness is 8 mu m, exposing the photoresist through a mask plate by using an exposure machine i-line, and measuring the exposure to 80mJ/cm < 2 >;

(3) And (3) baking in a baking oven at 100 ℃ for 30min, soaking and developing for 90s by using 2.38wt% TMAH, cleaning by using deionized water, and then baking after baking in the baking oven for 100 ℃/30min to finish the photoetching process, thereby obtaining the pattern complementary with the shading area of the mask.

Detection index

Adhesion properties	3 grade
		Acid and alkali resistance	Preferably, it is
Sensitivity to	80mJ/cm2

Example III

A negative photoresist composition resistant to strong acid corrosion having the composition shown in table three below;

table three: component of strong acid corrosion resistant negative photoresist composition III

Phenolic resin	30g
		Melamine derivatives	0.8g
Diphenyl iodohexafluorophosphate	20g
		Propylene glycol methyl ether acetate	40g

A process for photolithography of a negative photoresist composition resistant to strong acid corrosion comprising the steps of:

(1) Mixing phenolic resin, melamine derivative, diphenyl iodohexafluorophosphate and propylene glycol methyl ether acetate in proportion, fully dissolving, and filtering with a filter membrane with the aperture of 0.2 microns to obtain a photoresist solution;

(2) Spin-coating photoresist prepared from the components on a processed substrate, pre-baking (PAB) the photoresist by using a hot plate at 100 ℃/60s, regulating the rotating speed to ensure that the dried film thickness is 7 mu m, exposing the photoresist through a mask plate by using an exposure machine i-line, and measuring the exposure to 200mJ/cm < 2 >;

(3) And (3) baking in a baking oven at 100 ℃ for 30min, soaking and developing for 90s by using 2.38wt% TMAH, cleaning by using deionized water, and then baking after baking in the baking oven for 100 ℃/30min to finish the photoetching process, thereby obtaining the pattern complementary with the shading area of the mask.

Detection index

Adhesion properties	Grade 4
		Acid and alkali resistance	Preferably, it is
Sensitivity to	200mJ/cm2

Example IV

A negative photoresist composition resistant to strong acid corrosion having the composition shown in table four below;

table four: component of strong acid corrosion resistant negative photoresist composition IV

Phenolic resin	50g
		Melamine	2.3g
Triazine hexafluorophosphates	18g
		Propylene glycol methyl ether	52g

A process for photolithography of a negative photoresist composition resistant to strong acid corrosion comprising the steps of:

(1) Mixing phenolic resin, melamine derivative, triazine hexafluorophosphate and propylene glycol methyl ether in proportion, fully dissolving, and filtering with a filter membrane with the aperture of 0.2 microns to obtain a photoresist solution;

(2) Spin-coating photoresist prepared from the components on a processed substrate, pre-baking (PAB) the photoresist by using a hot plate at 100 ℃/60s, regulating the rotating speed to ensure that the dried film thickness is 6.5 mu m, exposing the photoresist through a mask plate by using an exposure machine i line, and measuring the exposure to 90mJ/cm < 2 >;

(3) And (3) baking in a baking oven at 100 ℃ for 30min, soaking and developing for 90s by using 2.38wt% TMAH, cleaning by using deionized water, and baking after baking for 140 ℃/30min by using the baking oven to finish the photoetching process, thereby obtaining the pattern complementary with the shading area of the mask.

Detection index

Adhesion properties	Grade 4
		Acid and alkali resistance	Preferably, it is
Sensitivity to	90mJ/cm2

The detection items in the first to fourth embodiments are all detected according to the national standard:

adhesion (Adherence): refers to the adhesion strength between the photoresist and the wafer.

Resist (Anti-etching): the photoresist film must maintain its adhesion and protect the liner surface during subsequent wet and dry etching, a property known as etch resistance.

Sensitivity (Sensitivity): the minimum energy value (or minimum exposure) of light of a certain wavelength required to produce a good pattern on the photoresist. Units: millijoules per square centimeter mJ/cm2.

From the first to fourth embodiments, the negative photoresist composition of the present invention has good adhesiveness, can bear strong acid corrosive liquid, can realize substitution of cyclized rubber used in the existing process, and does not contain harmful solvents such as xylene; the method adopts weak alkaline aqueous solution for development and deionized water for fixation, has no environmental hidden trouble, greatly improves the production environment and reduces the production cost.

The embodiments of the present invention have been described in detail with reference to examples, but the present invention is not limited to the described embodiments. It will be apparent to those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, and yet fall within the scope of the invention.

Claims (2)

1. A negative photoresist composition resistant to strong acid corrosion, characterized by: the composite material consists of the following components in parts by weight:

50g of phenolic resin, 0.5g of benzomelamine, 20g of diphenyl p-benzylidene trifluoro methane sulfonate and 47g of propylene glycol methyl ether acetate.

2. A process for photolithography of the negative photoresist composition resistant to strong acid corrosion according to claim 1, wherein: the method comprises the following steps:

(1) Mixing phenolic resin, benzoguanamine, diphenyl p-benzylidene trifluoro methane sulfonate and propylene glycol methyl ether acetate according to a proportion, fully dissolving, and filtering by using a filter membrane with the aperture of 0.2 microns to obtain a photoresist solution;

(2) On a treated substrateSpin-coating photoresist prepared from the components, pre-baking PAB at 100deg.C/90 s with a hot plate, adjusting rotation speed to make the dried film thickness 8 μm, exposing with i-line of exposure machine via mask plate, and measuring exposure to 80mJ/cm ² ；

(3) And (3) baking in a baking oven at 100 ℃ for 30min, soaking and developing for 90s by using 2.38wt% TMAH, cleaning by using deionized water, and then baking after baking in the baking oven for 100 ℃/30min to finish the photoetching process, thereby obtaining the pattern complementary with the shading area of the mask.