TWI431112B - Hydroxylamine - containing cleaning solution and its application - Google Patents

Description

Hydroxylamine-containing cleaning solution and application thereof

The present invention relates to a hydroxylamine-containing cleaning liquid and uses thereof.

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 (ie, after coating, imaging, ion implantation, and etching of the photoresist layer). Ion bombardment in the doping step hardens the photoresist 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 uses 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 current wet cleaning process, the most used cleaning solution is a cleaning solution containing hydroxylamine. This kind of cleaning liquid is mainly developed by EKC and ACT, and has a large market share. Typical patents are US6110881, US6319885, US5672577, US6030932, US6825156 and US5419779. The main feature of this type of cleaning fluid is the use of catechol as one of its main components; catechol is a toxic substance that has been restricted in many countries. Therefore, with the increasing awareness of environmental protection, more and more companies hope to use the hydroxylamine solution containing no catechol to remove the residue of the photoresist layer material to ensure the health of the operators and better operating environment.

It is an object of the present invention to overcome the above-discussed deficiencies in the prior art. Providing a more environmentally friendly hydroxylamine-containing cleaning solution that maintains the cleaning power of conventional hydroxylamine cleaning fluids while having a lower rate of corrosion to metals and non-metals.

The cleaning solution of the invention contains:

1) Solvent: 10~80%;

2) Water: 10~45%;

3) Hydroxylamine: 1~40%;

4) mercaptan benzothiazole organic matter: 0.1~10%;

In the present invention, the solvent may be selected from one or more of the group consisting of anthraquinone, anthracene, imidazolidinone, pyrrolidone, imidazolidinone, ether, decylamine and an alcoholamine, preferably an alcoholamine. Wherein, the hydrazine is preferably dimethyl hydrazine; the hydrazine is preferably cyclobutyl hydrazine; and the imidazolidinone is preferably 1,3- dimethyl-2-imidazole. The alkyl ketone; the pyrrolidone is preferably N-methylpyrrolidone; the imidazolidinone is preferably 1,3-dimethyl-2-imidazolidinone (DMI); Preferred is dimethylformamide; the ether is preferably propylene glycol monomethyl ether or dipropylene glycol monomethyl ether. The alcoholamine is preferably monoethanolamine, diethanolamine, triethanolamine, isopropanolamine, 2-(diethylamino)ethanol, ethyldiethanolamine and diglycolamine.

The invention still further comprises water.

The invention still further comprises hydroxylamine.

In the present invention, the thiol benzothiazole organic substance means an organic substance having the following structure.

Wherein: the substituents R1, R2, R3, and R4 may independently be a hydrogen atom, a hydroxyl group, a thiol group, a carboxyl group, a sulfonic acid group, or an organic substituent of C1-C6. Preference is given to thiol benzothiazole organic compounds in which two or more substituents of R1, R2, R3 and R4 are hydroxyl groups.

The cleaning liquid of the present invention can be obtained by simply and uniformly mixing the above components.

The cleaning solution of the present invention is used for removing the photoresist residue, and after removing the etching residue on the wafer with the photoresist cleaning liquid, it is then rinsed and dried.

The positive progress of the invention is that the toxic substance catechol used in the traditional hydroxylamine cleaning liquid is successfully replaced by adding the thiol benzothiazole organic substance, and the current cleaning ability of the hydroxylamine cleaning liquid is retained. At the same time, the corrosion rate of metal and non-metal is small; the environment is friendly, which is beneficial to ensure the health of operators and better operating environment.

The invention is further illustrated by the following examples.

Example 1~20

In order to further illustrate the effects of the present invention, we have selected some examples to test the corrosion rate of metallic aluminum, non-metal plasma enhanced cerium oxide (PETEOS) and to clean three different types of wafers. 2.

Test method for metal corrosion rate of solution:

1) Using the Napson four-point probe instrument to test the initial resistance value (Rs1) of the 4*4 cm aluminum blank sheet;

2) immersing the 4*4 cm aluminum blank sheet in a solution that has been previously thermostated to a set temperature for 60 minutes;

3) take out the 4*4cm aluminum blank slab, rinse it with high-purity nitrogen, and test the resistance value (Rs2) of the 4*4cm aluminum blank slab using a Napson four-point prober;

4) 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:

1) Testing the thickness (T1) of the 4*4 cm PETEOS cymbal using a Nanospec 6100 thickness gauge;

2) soaking the 4*4 cm PETEOS tablet in a solution that has been previously thermostated to a set temperature for 60 minutes;

3) take out the 4*4cm PETEOS slab, rinse it with high-purity nitrogen, and test the thickness of the 4*4cm PETEOS slab using the Nanospec6100 thickness gauge (T2);

4) Enter the above thickness value and soak time into the appropriate program to calculate the corrosion rate.

Wafer cleaning method:

1) placing the wafer to be cleaned into a solution that has been previously thermostated to a set temperature;

2) Soak the wafer according to the principle of immersing the wire for 20 minutes, immersing the channel and the metal pad for 30 minutes;

3) After the immersion time is reached, the wafer is taken out, rinsed with high-purity nitrogen gas, and sent to the SEM test.

It can be seen from Table 2 that the cleaning liquid composition of the present invention does not substantially erode metals (such as metal aluminum) and non-metals (such as PETEOS) used in semiconductor fabrication, and the corrosion rate thereof is mostly smaller than that of the semiconductor industry. 2 angstroms per minute required. Cleaning the plasma etch residue with this solution revealed that the plasma etch residue was removed and there was no corrosion of metals and non-metals. It is indicated that the cleaning liquid of the invention has a low corrosion rate of metal and non-metal, and can clean the metal wire, the channel and the metal pad.

In summary, the positive progress of the present invention is as follows: 1) A semiconductor wafer cleaning solution which is environmentally friendly and maintains the cleaning ability of a conventional hydroxylamine cleaning solution is provided. It is beneficial to ensure the health of the operators and better operating environment; 2) its corrosion rate to metals and non-metals is small.

Claims (8)

A hydroxylamine-containing cleaning solution comprising: a solvent, water, hydroxylamine, thiol benzothiazole organic substance, and the mass percentage of the solvent is 10 to 80%; and the mass percentage of the water is 10 to 45%. The content of the hydroxylamine is 1% to 40% by mass; the mass percentage of the thiol benzothiazole organic substance is 0.1% to 10%. The cleaning solution according to claim 1, wherein the solvent is one or more selected from the group consisting of an anthraquinone, an anthracene, an imidazolidinone, a pyrrolidone, an imidazolidinone, an ether, a guanamine, and an alcohol amine. The cleaning solution according to claim 2, wherein the hydrazine is dimethyl hydrazine; the hydrazine is cyclobutyl hydrazine; and the imidazolidinone is 1,3-dimethyl- 2-imidazolidinone; the pyrrolidone is N-methylpyrrolidone; the imidazolidinone is 1,3-dimethyl-2-imidazolidinone; the guanamine is dimethylformamide The ether is propylene glycol monomethyl ether and / or dipropylene glycol monomethyl ether; the alcohol amine is selected from the group consisting of monoethanolamine, diethanolamine, triethanolamine, isopropanolamine, 2-(diethylamino)ethanol, One or more of ethyl diethanolamine and diglycolamine. The cleaning solution according to claim 2, wherein the solvent is selected from the group consisting of monoethanolamine, diethanolamine, triethanolamine, isopropanolamine, 2-(diethylamino)ethanol, ethyldiethanolamine, and diethylene glycol. One or more of the amines. The cleaning liquid according to claim 1, wherein the thiol benzothiazole organic substance has the following structure: The cleaning liquid according to claim 5, wherein the substituents R1, R2, R3, and R4 are independently selected from one or more of a hydrogen atom, a hydroxyl group, a thiol group, a carboxyl group, and a sulfonic acid group. The cleaning liquid according to claim 6, wherein the substituent R1, R2, R3, and R4 have two or more thiol benzothiazole organic compounds having a substituent of a hydroxyl group. The use of the cleaning solution according to any one of claims 1 to 7 for removing the residue of the photoresist layer.