WO2010037266A1

WO2010037266A1 - Rinse solution for removal of etching residues

Info

Publication number: WO2010037266A1
Application number: PCT/CN2009/001085
Authority: WO
Inventors: 刘兵; 彭洪修; 于昊
Original assignee: Liu Bing; Peng Libbert Hongxiu; Yu Joey Hao
Priority date: 2008-09-26
Filing date: 2009-09-25
Publication date: 2010-04-08
Also published as: CN101685273A; CN101685273B

Abstract

A rinse solution for removal of etching residues includes N,N-diethyl ethanolamine, other alcohol amine, water and chelanting agent. And the corrosion rate of the rinse solution to some metals and some non-metals is low. The rinse solution can be used to remove etching residues of the wafer. And the rinse solution can be used in micro electronic field for the cleaning of metals and semiconductor wafer.

Description

Cleaning liquid for removing photoresist layer residue

The present invention relates to a cleaning liquid in a semiconductor manufacturing process, and more particularly to a cleaning liquid for removing a residue of a photoresist layer.

technical background

In the fabrication of semiconductor components, the application, exposure and imaging of the photoresist layer are necessary process steps for the pattern fabrication of the components. The residue of the photoresist layer material needs to be completely removed before the next process step (i.e., after coating, imaging, ion implantation, and etching of the photoresist layer). Ion bombardment in the doping step hardens the photoresist layer polymer, thus making the photoresist layer less soluble and more difficult to remove. Up to now, in the semiconductor manufacturing industry, this layer of photoresist film has been removed using a two-step process (dry ashing and wet etching). The first step utilizes dry ashing to remove most of the photoresist layer (PR); the second step utilizes the corrosion inhibitor composition wet etch/clean process to remove and clean the remaining photoresist layer, typically in the form of a cleaning solution. / rinse / deionized water rinse. Only the residual polymer photoresist layer and inorganic matter can be removed in this process, and the damage to the metal layer such as the aluminum layer cannot be attacked.

In the semiconductor cleaning industry, it is generally required that the cleaning liquid can effectively remove the photoresist residue, and the corrosion rate of the contact metal and non-metal is less than 2 A/min. In the current wet cleaning process, the most used cleaning liquid is a cleaning liquid containing hydroxylamines and fluorine-containing cleaning liquids. Typical patents of hydroxylamine cleaning liquids are US6319885, US5672577, US6030932, US6825156 and US5419779. After continuous improvement, the corrosion rate of the solution itself to the aluminum metal has been greatly reduced. However, since such a cleaning liquid has a problem of single source, easy explosion and high cost due to the use of hydroxylamine, it is necessary to reduce the raw material cost. Although existing fluoride-based cleaning solutions have been greatly improved, such as US 5,972,862, US 6,828,289, etc., there is still a good control of the corrosion of metal and non-metal substrates at the same time, which is easy to cause channel feature size after cleaning. On the other hand, because some mainstream semiconductor companies use wet cleaning equipment made of quartz, and fluorine-containing cleaning solutions corrode quartz. Corrosion increases with increasing temperature, so there is a problem of incompatibility with existing quartz devices, which affects its widespread use.

Therefore, although some cleaning liquid compositions containing hydroxylamines and fluorine-containing ones have been disclosed, there is a need to prepare a cleaning composition or system which is less expensive, more stable in performance, and has a lower corrosion rate to metals and non-metals. To accommodate new cleaning requirements and to be compatible with quartz equipment. Summary of invention

The object of the present invention is to provide a semiconductor wafer cleaning solution capable of removing photoresist residue on a wafer, which has low corrosion rate to metal and non-metal, stable performance, and low cost; and quartz device compatible.

The cleaning solution of the present invention comprises: N, N-diethylethanolamine, other alcoholamines, water, and a chelating agent. In the present invention, the content of the N, N-diethylethanolamine is 5 to 60% by weight.

In the present invention, the other alcoholamines are preferably monoethanolamine, diethanolamine, triethanolamine, isopropanolamine, ethyldiethanolamine, N-(2-aminoethyl)ethanolamine and diglycolamine; The other alkanolamine is present in an amount of from 10 to 60% by weight.

In the present invention, the water is contained in an amount of from 1 to 45% by weight.

In the present invention, the chelating agent refers to an organic compound containing a plurality of functional groups; the chelating agent content is 0.1 to 20% by weight; the chelating agent is preferably glycolic acid, malonic acid, citric acid, iminodiacetic acid, ammonia triacetic acid , ethylenediaminetetraacetic acid, catechol, pyrogallol, gallic acid, salicylic acid and sulfosalicylic acid.

In the present invention, a corrosion inhibitor may further be included. The corrosion inhibitor may be a corrosion inhibitor commonly used in the art, preferably from a mineral acid, a carboxylic acid, a benzotriazole, a phosphonate inhibitor, and the like. Wherein, the inorganic acid includes boric acid, phosphoric acid; the carboxylic acid (acetate) includes acetic acid, citric acid, benzoic acid, p-aminobenzoic acid, methyl p-aminobenzoate, phthalic acid, methyl phthalate, etc.; And the triazoles are benzotriazole, methylbenzotriazole, 5-carboxybenzotriazole, 1-hydroxybenzotriazole; phosphonates include 1,3- ( Hydroxyethyl) -2,4,6- Triphosphonic acid or the like; the content of the corrosion inhibitor is 10% by weight or less.

The reagents and starting materials used in the present invention are commercially available. The cleaning liquid of the present invention can be obtained by simply and uniformly mixing the above components. After removing the etching residue on the wafer with the photoresist cleaning solution, it can be directly rinsed and then dried.

The positive effects of the present invention are: Providing a cleaning solution free of hydroxylamine and fluorine which does not corrode quartz and is compatible with quartz equipment. It solves the problem that the hydroxylamine in the traditional hydroxylamine-containing cleaning solution is single, explosive and expensive, thereby saving costs. Moreover, the cleaning solution can remove the photoresist residue on the wafer well, and the corrosion rate of the metal and the non-metal is small.

Summary of the invention

The invention is further illustrated by the following examples. Example 1~23

Table 1 shows the formulations of Examples 1 to 23 of the present invention, and the components of each of the examples were simply mixed to obtain the cleaning liquid of the present invention. Table 1 Examples of the present invention Formulations 1 to 23 Real N, N-diethyl Alcohol amine solvent Water chelating agent Corrosion inhibitors Percent ethanolamine Amount, content, content,

Name Content, % Name Name Example Content, % % % %

1 5 monoethanolamine 60 30 glycolic acid 5 N/A N/A

2 60 diethanolamine 10 28 malonic acid 2 N/A N/A

3 50 triethanolamine 48.9 1 catechol 0.1 N/A N/A

4 15 isopropanolamine 20 45 catechol 20 N/A N/A

5 40 N-(2-Ammonia 38.5 20 Iminodiacetic acid 0.5 Boric acid 1 Ethanolamine

Ethyl diacetate

30 28.8 40 Ammonia triacetate 0.1 Phosphoric acid 0.1 Alcoholamine

Benzotriazine

20 diethylene glycolamine 59.9 10' ethylenediaminetetraacetic acid 0.1 10 azole methyl benzo

10 monoethanolamine 58 15 pyrogallol 15 2 triazole

N-(2-ammonia

5-carboxybenzene

25 33 25 Gallic acid 10 7 and triazole Ethanolamine

1-hydroxybenzene

35 monoethanolamine 35 23 salicylic acid 2 5 triazole

1,3-(hydroxyethyl)

45 diglycolamine 14.9 35 sulfosalicylic acid 5 0.1

-2,4,6-triphosphonic acid

35 diethylene glycolamine 32 25 citric acid 5 boric acid 3 citric acid 3 acetic acid 0.2 p-aminobenzene glycolic acid 2 0.2

50 triethanolamine 18.5 25 formic acid phthalic acid ethylenediaminetetraacetic acid 1 0.1 methyl ester phthalate

35 monoethanolamine 15 25 0.4 glycolic acid 2 acid triethanolamine 18.5 citric acid 3 P-aminobenzene

Ethylenediaminetetraacetic acid 1 0.1 methyl formate triethanolamine 18 citric acid 3.5

30 25 glycolic acid 2 benzoic acid 0.5 diglycolamine 20

Iminodiacetic acid 1 triethanolamine 15 citric acid 3

20 monoethanolamine 18 25 glycolic acid 2 boric acid 1 diglycolamine 15 iminodiacetic acid 1

50 triethanolamine 19.5 25 citric acid 3.5 N/A N/A glycolic acid 1 ethylenediaminetetraacetic acid 1

50 triethanolamine 23.5 20 citric acid 3.5 boric acid 1 glycolic acid 1 ethylenediaminetetraacetic acid 1

40 diethylene glycolamine 38.5 20 iminodiacetic acid 0.5 boric acid 1

30 monoethanolamine 48 15 gallic acid 5 methylbenzo 2 triazole

20 diethylene glycolamine 49.9 25 salicylic acid 5 1,3- (hydroxyl 0.1 ethyl)

-2,4,6-triphosphonic acid

45 monoethanolamine 33 15 catechol 2 boric acid 5

20 triethanolamine 15 25 citric acid 3 boric acid 2 monoethanolamine 17 glycolic acid 2 diglycolamine 15 iminodiacetic acid 1

Effect embodiment In order to further embody the effects of the present invention, the present invention selects Examples 17 to 23 to clarify the effects of the present scheme, and these examples are subjected to corrosion rate test and cleaning ability test. The test content is as follows:

1. Effect of the Invention Example of metal aluminum and non-metal SiO ₂ (quartz) corrosion rate test at different temperatures.

Conventional hydroxylamine-containing and fluorine-containing cleaning fluids were compared to the effect examples of the present invention. Among them, the traditional hydroxylamine cleaning solution formula: 55% ethanolamine, 30% aqueous hydroxylamine solution (the mass ratio of hydroxylamine to water in this solution is 1: 1), 7% water, 8% catechol. A fluorine-containing cleaning solution: 60.4% dimethylacetamide, 25% water, 7.6% ammonium acetate, 6% acetic acid, 1% ammonium fluoride. The test results are shown in Table 2.

Test method for metal corrosion rate of solution:

a) using a Napson four-point probe to test the initial value of the resistance of the 4X4cm aluminum blank silicon wafer (R _Sl ); b) immersing the 4X4 cm aluminum blank silicon wafer in a solution that has been previously thermostated to a specified temperature for 30 minutes;

c) taking out the 4×4 cm aluminum blank silicon wafer, washing with deionized water, drying with high purity nitrogen gas, and testing the resistance value (Rs ₂ ) of the 4×4 cm aluminum blank silicon wafer by using a Napson four-point probe instrument;

d) Enter the resistance value and soak time into the appropriate program to calculate the corrosion rate.

Test method for non-metallic corrosion rate of solution:

a) testing the thickness (Tj) of the 4X4 cm SiO ₂ silicon wafer using a Nanospec 6100 thickness gauge;

b) immersing the 4X4cm Si0 ₂ silicon wafer in a solution that has been previously thermostated to a specified temperature for 30 minutes;

c) take out the 4X4cmSi0 ₂ silicon wafer, wash it with deionized water, dry it with high purity nitrogen, and test the thickness (T ₂ ) of 4X4cm Si0 ₂ silicon wafer with Nanospec6100 thickness gauge; d) input the above thickness value and soaking time The corrosion rate can be calculated by a suitable procedure. Table 2 Comparative Example and Effect Example Metal Aluminum and Non-Metal Si0 ₂ Corrosion Rate at Different Temperatures

In the semiconductor cleaning industry, it is generally required that the cleaning liquid can effectively remove the photoresist residue, and the corrosion rate of the contact metal and non-metal is less than 2 A/min. For traditional hydroxylamine solutions, the corrosion rate of aluminum metal is generally slightly larger than the standard requirements, but the non-metal corrosion rate is generally low (<0.2), and there is no significant change with temperature. This is indicated in the test results of Comparative Example 1 in Table 2. Fluorine-containing cleaning fluids generally have a corrosion rate of less than 2 A/min at operating temperatures, but their greatest disadvantage is that the non-metallic corrosion rate increases with increasing temperature. As can be seen from Table 2, the corrosion rate of silica of Comparative Example 2 did increase with increasing temperature, so such a cleaning solution could not use a conventional quartz tank apparatus. Table 2 shows that the cleaning solution of the present invention has a metal aluminum corrosion rate lower than that of the conventional hydroxylamine solution, and can even reach a level comparable to that of the fluorine-based cleaning liquid, and retains a low non-metal corrosion rate (<0.2). , with no significant change in temperature, compatible with quartz equipment.

2, the results of the effect of different wafer cleaning results

The effect embodiment is used to perform cleaning tests on different wafers. The test results are shown in Table 3.

Table 3 results of the effect of different wafer cleaning

Metal Channel (Via) Metal Pad (Pad) Test Dissolution

Cleaning knot cleaning strip cleaning solution cleaning condition cleaning result cleaning condition

Fruits are clean, the base is clean, the base effect is 65 °C clean, base 65 °C 65 °C

This non-corrosion This non-corrosion Example 17 / 30min No corrosion / 30min / 30min

The corrosion effect is 65 °C clean, no 65V clean, no 65 °C thousand clean, no application 18 / 30min corrosion / 30min corrosion / 30min corrosion Clean, clean, base effect 70 °C clean, base 70 ° C 70V

This non-corrosion This non-corrosion Example 19 / 30min This is no corrosion /30min /30min

The effect of the erosion is 65 °C clean, no 65 °C clean, no 65 °C clean, no application 20 / 30min corrosion / 30min decay candle / 30min corrosion effect 65 V clean, no 65. C thousand clean, no 65V clean, no application 21 / 30min corrosion / 30min corrosion / 30min corrosion effect 65 V clean, no 65V clean, no 65 °C clean, no application 22 / 30min corrosion / 30min corrosion / 30min corrosion Clean, clean, base effect 75 V clean, base 75 °C 75 °C

This non-corrosion This non-corrosion Example 23 /30min This is no corrosion /30min /30min

Corrosion Table 3 shows that: Effects Examples 17 to 23 can effectively remove photoresist residues of three kinds of wafers (metal wires, metal; channels, Via; metal pads, pads) without significantly affecting metals and non-metals. Corrosion, good cleaning effect.

In summary, the positive progress of the present invention over conventional cleaning solutions is:

1) The cleaning liquid of the invention can effectively remove the photoresist residues, and the corrosion rate of the metal aluminum is lower than that of the conventional hydroxylamine solution, and can even reach the level equivalent to the fluorine-based cleaning liquid, and the non-metal is retained. Corrosion rate is low (<0.2), with no significant change in temperature; but does not contain hydroxylamine and fluoride.

2) The cleaning liquid of the invention solves the problems of high cost, easy explosion and single source of hydroxylamine in the traditional hydroxylamine cleaning liquid, and is beneficial to reducing the cost;

3) The cleaning liquid of the present invention has a low non-metal corrosion rate (<0.2), and has no obvious change with temperature; it is compatible with quartz equipment.

Claims

Rights request

A cleaning solution for removing residues of a photoresist layer comprising: N, N-diethylethanolamine, other alkanolamines, water and a chelating agent.

The cleaning solution according to claim 1, wherein the N, N-diethylethanolamine is contained in an amount of 5 to 60% by weight.

3. The cleaning solution according to claim 1, wherein: the other alcoholamine is selected from the group consisting of monoethanolamine, diethanolamine, triethanolamine, isopropanolamine, ethyldiethanolamine, and N-(2-aminoethyl). One or more of ethanolamine and diglycolamine.

4. The cleaning solution according to claim 1, wherein: the content of the other alcoholamine is 10 to 60% by weight _o

The cleaning solution according to claim 1, wherein the water is contained in an amount of from 1 to 45% by weight.

The cleaning solution according to claim 1, wherein the chelating agent is an organic compound containing a plurality of functional groups.

The cleaning solution according to claim 6, wherein the chelating agent is selected from the group consisting of glycolic acid, malonic acid, citric acid, iminodiacetic acid, aminotriacetic acid, ethylenediaminetetraacetic acid, and o-phenylene One or more of phenol, pyrogallol, gallic acid, salicylic acid, and sulfosalicylic acid.

The cleaning solution according to claim 1, wherein the chelating agent is contained in an amount of 0.1 to 20% by weight.

The cleaning liquid according to claim 1, wherein the cleaning liquid further comprises a corrosion inhibitor.

The cleaning solution according to claim 9, wherein said corrosion inhibitor is one or more of a mineral acid, a carboxylic acid, a benzotriazole, and a phosphonate. .

The cleaning solution according to claim 10, wherein the inorganic acid is boric acid and/or phosphoric acid; and the carboxylic acid (ester) is selected from the group consisting of acetic acid, citric acid, benzoic acid, p-aminobenzoic acid, One or more of methyl p-aminobenzoate, phthalic acid and methyl phthalate; the benzotriazole is selected from the group consisting of benzotriazole and methylbenzotriazole, 5-carboxybenzotriazole and 1-hydroxybenzene And one or more of triazole; the phosphonate is 1,3-(hydroxyethyl)-2,4,6-triphosphonic acid.

The cleaning solution according to claim 9, wherein the corrosion inhibitor is contained in an amount of 10 wt%/cm or less and does not include 0 wt%.