CN112229987A

CN112229987A - Method for testing alkali dissolution rate of linear phenolic resin for photoresist

Info

Publication number: CN112229987A
Application number: CN202010816380.1A
Authority: CN
Inventors: 崔淑杰; 杨欣; 贾宏平; 李永强
Original assignee: Shaanxi Rainbow New Materials Co ltd
Current assignee: Shaanxi Rainbow New Materials Co ltd
Priority date: 2020-08-14
Filing date: 2020-08-14
Publication date: 2021-01-15

Abstract

The invention relates to a method for testing the alkali dissolution rate of linear phenolic resin for photoresist, which comprises the following steps: weighing and dissolving a sample; forming a film by using a sample solution; measuring the film thickness; alkaline dissolution rate measurement. The method comprises the steps of accurately weighing a certain amount of linear phenolic resin, dissolving the linear phenolic resin in a specific solvent, forming a film layer with a certain thickness on a silicon wafer from the obtained solution, curing the film layer, measuring the film thickness of a specific position, developing the cured film layer, measuring the developed film thickness, and calculating the alkali dissolution rate of the linear phenolic resin. The measuring method provided by the invention has the advantages of rapidness, accuracy and representativeness, and can be applied to the production process of the photoresist in a large scale.

Description

Method for testing alkali dissolution rate of linear phenolic resin for photoresist

The technical field is as follows:

the invention belongs to the technical field of photoresist, and particularly relates to a method for testing the alkali dissolution rate of linear phenolic resin for photoresist.

Background art:

photoresists, also known as photoresists, are media for pattern transfer by photochemical reactions and are a class of fine chemicals with a wide variety, diverse properties, and extremely wide application. The photoresist is mainly applied to the fine processing process of integrated circuits and semiconductor discrete devices in the electronic industry, utilizes photochemical reaction, transfers required fine patterns from a mask plate to a substrate to be processed through exposure and development, and then carries out processes such as etching, diffusion, ion implantation, metallization and the like. In the production process of the photoresist, the most important is to control the consistency of the product quality, the key for ensuring the consistency of the product quality is to measure raw materials, the linear phenolic resin is the most important raw material in the production process of the photoresist, and the alkali dissolution rate is a key technical index for configuring the photoresist. How to rapidly and accurately measure the alkaline dissolution rate of the linear phenolic resin for the photoresist becomes a key.

The invention content is as follows:

in order to ensure the consistency of the quality of photoresist products, the invention aims to provide a method for testing the alkali dissolution rate of the linear phenolic resin for the photoresist, which has rapidness, accuracy and representativeness and can be applied to the production process of the photoresist in a large scale.

In order to achieve the purpose, the invention adopts the technical scheme that: a method for testing the alkali dissolution rate of a linear phenolic resin for photoresist is characterized by comprising the following steps,

step S1)

Resin dissolution: accurately weighing a certain amount of phenolic novolac resin, dissolving the phenolic novolac resin in a solvent at 30-40 ℃, continuing stirring for 10-12 hours after the phenolic novolac resin is completely dissolved, and stopping stirring.

Step S2)

Film forming by using resin solution: the silicon wafer is placed on a rotary film coating instrument, the resin solution is sucked by a syringe and dripped at the center of the silicon wafer, a vacuum switch of the rotary film coating instrument is turned on, and spin coating is started. After the rotary coating is finished, pre-baking the silicon wafer on a hot plate, and then curing the film layer in a vacuum drier.

Step S3)

And (3) measuring the film thickness: the cured silicon wafer was measured for film thickness at nine locations, the test locations are referenced in fig. 1, and then an average value was calculated, which is the average film thickness before development.

Step S4)

Alkali dissolution rate measurement: placing the silicon wafer in a developing solution, taking out after soaking for a period of time, drying for 5min in an oven under 110 ℃ after rinsing with ultrapure water, measuring the film thicknesses of nine positions on the developed silicon wafer, and then calculating an average value, wherein the average value is the average film thickness after development; alkali dissolution rate of novolac resin:

in one embodiment, the mass ratio of the phenolic novolac resin to the solvent is 1 (1-5).

In one embodiment, the solvent is propylene glycol methyl ether acetate.

In one embodiment, the pre-baking temperature is 85-95 ℃ and the time is 60-90 s.

In one embodiment, the curing temperature is 120-130 ℃ and the curing time is 60-120 s.

In one embodiment, the developer is tetramethylammonium hydroxide (TMAH, 2.38%).

The development time is 25-45 s.

From the above, the main advantages of the present invention are:

1. the method can quickly and accurately measure the alkali dissolution rate of the linear phenolic resin for the photoresist.

2. The invention can ensure the consistency of the quality of the photoresist product.

Description of the drawings:

FIG. 1 is a diagram showing a position of measurement of a film thickness of a silicon wafer;

FIG. 2 is a flow chart of a method for testing the alkali dissolution rate of a novolak resin for a photoresist.

The specific implementation mode is as follows:

in order that the present invention may be better understood, the following examples are set forth. It will be understood by those skilled in the art that the present invention is not limited to the embodiments illustrated.

Example one

A method for testing the alkali dissolution rate of a linear phenolic resin for photoresist comprises the following steps:

step S1

Resin dissolution: weighing 10g of linear phenolic resin, dissolving the linear phenolic resin in 30g of propylene glycol methyl ether acetate at 40 ℃, continuing stirring for 10 hours after the linear phenolic resin is completely dissolved, and stopping stirring.

Step S2

Film forming by using resin solution: the silicon wafer is placed on a rotary film coating instrument, the resin solution is sucked by a syringe and dripped at the center of the silicon wafer, a vacuum switch of the rotary film coating instrument is turned on, and spin coating is started. After the spin coating was completed, the silicon wafer was pre-baked with a hot plate at 95 ℃ for 80s and cured with a vacuum drier at 120 ℃ for 60 s.

Step S3

And (3) measuring the film thickness: the thickness of the film layer at nine positions was measured on the cured silicon wafer, the test positions were referred to in FIG. 1, and the average value was calculated as

Step S4

Alkali dissolution rate measurement: placing the silicon wafer in TMAH with concentration of 2.38%, soaking for 20s, taking out, washing with ultrapure water, drying in oven at 110 deg.C for 5min, measuring the film thickness of the developed silicon wafer at nine positions, referring to figure 1, and calculating average value

The alkali dissolution rate of the novolak resin was calculated by the following formula

Example two

step S1)

Resin dissolution: 30g of linear phenolic resin is weighed and dissolved in 70g of propylene glycol methyl ether acetate at 40 ℃, and after the linear phenolic resin is completely dissolved, stirring is continued for 10 hours, and the stirring is stopped.

Step S2)

Film forming by using resin solution: the silicon wafer is placed on a rotary film coating instrument, the resin solution is sucked by a syringe and dripped at the center of the silicon wafer, a vacuum switch of the rotary film coating instrument is turned on, and spin coating is started. After the spin coating was completed, the silicon wafer was pre-baked with a hot plate at 95 ℃ for 80s and cured with a vacuum drier at 130 ℃ for 90 s.

Step S3)

Step S4)

Alkali dissolution rate measurement: placing the silicon wafer in TMAH with concentration of 2.38%, soaking for 25s, taking out, washing with ultrapure water, drying in oven at 110 deg.C for 5min, measuring the film thickness of the developed silicon wafer at nine positions, referring to figure 1, and calculating average value

EXAMPLE III

step S1)

Resin dissolution: 140g of phenolic novolac resin is weighed and dissolved in 360g of propylene glycol methyl ether acetate at 40 ℃, and after the phenolic novolac resin is completely dissolved, stirring is continued for 12 hours, and the stirring is stopped.

Step S2)

Film forming by using resin solution: the silicon wafer is placed on a rotary film coating instrument, the resin solution is sucked by a syringe and dripped at the center of the silicon wafer, a vacuum switch of the rotary film coating instrument is turned on, and spin coating is started. After the spin coating was completed, the silicon wafer was pre-baked with a hot plate at 90 ℃ for 90 seconds and cured with a vacuum drier at 120 ℃ for 100 seconds.

Step S3)

Step S4)

The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above-described embodiments. Modifications and variations that may occur to those skilled in the art without departing from the spirit and scope of the invention are to be considered as within the scope of the invention.

Claims

1. A method for testing the alkali dissolution rate of a linear phenolic resin for photoresist is characterized by comprising the following steps,

step S1)

Resin dissolution: accurately weighing a certain amount of linear phenolic resin, dissolving the linear phenolic resin in a solvent at 30-40 ℃, continuing stirring for 10-12 hours after the linear phenolic resin is completely dissolved, and stopping stirring;

step S2)

Film forming by using resin solution: the silicon wafer is placed on a rotary film coating instrument, the resin solution is sucked by a syringe and dripped at the center of the silicon wafer, a vacuum switch of the rotary film coating instrument is turned on, and spin coating is started. After the rotary coating is finished, pre-baking the silicon wafer on a hot plate, and then curing a film layer in a vacuum drier;

step S3)

And (3) measuring the film thickness: measuring the film thickness of the cured silicon wafer at nine positions, referring to a test position as shown in figure 1, and then calculating an average value, wherein the average value is the average film thickness before development;

step S4)

Alkali dissolution rate measurement: placing the silicon wafer in a developing solution, taking out after soaking for a period of time, washing with ultrapure water, drying in an oven at 110 ℃ for 5min, measuring the film thicknesses of nine positions of the developed silicon wafer, and calculating an average value, wherein the average value is the average film thickness after development; alkali dissolution rate of novolac resin:

2. the method for measuring an alkali dissolution rate of a phenol novolac resin for a photoresist according to claim 1, wherein the weight ratio of the phenol novolac resin to the solvent is 1:1 to 5.

3. The method for measuring the alkali dissolution rate of a phenol novolac resin for a photoresist according to claim 1, wherein the solvent is propylene glycol methyl ether acetate.

4. The method for measuring the alkali dissolution rate of a novolak resin for a photoresist according to claim 1, wherein said prebaking temperature is 85 to 95 ℃ for 60 to 90S.

5. The method for testing the alkali dissolution rate of the phenolic novolac resin for photoresist as claimed in claim 1, wherein the curing temperature is 120 ℃ and 130 ℃ and the time is 60-120S.

6. The method for testing the alkali dissolution rate of the phenolic novolac resin for photoresist according to claim 1, wherein the developing solution is tetramethylammonium hydroxide (TMAH) with an effective content of 2.38%.

7. The method for measuring an alkali dissolution rate of a novolak resin for a photoresist according to claim 1, wherein said developing time is 25 to 45S.