KR20170064736A - Photoresist Stripping Method Using Organic Solvent - Google Patents

Abstract

The present invention provides a method for removing photoresist by treating an organic solvent at a high temperature. By treating the organic solvent according to the present invention, the photoresist can be removed from the surface of the semiconductor without damage due to etching, oxidation, or the like.

Description

[0001] The present invention relates to a photoresist stripping method using an organic solvent,

The present invention relates to a method for removing photoresist by treating a high temperature organic solvent.

Conventional photoresist stripping techniques remove the bulk of the photoresist by removing the implanted photoresist on silicon or treating the organic solvent by treating the sulfuric acid mixture (SPM) or ozonated water, . However, the method of treating with SPM or ozone water causes a slight deformation on the surface of the semiconductor, which is difficult to apply to highly integrated transistors. In general, when an organic solvent is treated at a low temperature or a normal temperature, there is a problem that the crust and residue of the ion-implanted photoresist can not be efficiently removed.

Korean Patent Publication No. 2012-0036030

The present invention relates to a method for removing photoresist by treating a high temperature organic solvent, wherein a high dose implant photoresist processed semiconductor is treated by removing the organic solvent. In particular, it is an object of the present invention to provide a photoresist removing method that does not cause damage to the surface of Ge or III-V semiconductor by etching or oxidation.

According to the present invention,

And removing the photoresist by treating the photoresist-treated semiconductor with an organic solvent at a temperature of 110 캜 or higher.

The photoresist removing method according to the present invention can effectively remove the photoresist without damaging the semiconductor surface by etching or oxidation.

1 is a schematic view showing a process of removing a photoresist according to the present invention.
Figure 2 is a graph showing the thickness of the photoresist residue with temperature during photoresist removal.
FIG. 3 is an image of a scanning electron microscope (SEM) in which a semiconductor supported on an organic solvent is photographed at each temperature.
4 is an image of an atomic force microscope (AFM) in which a semiconductor supported on an organic solvent is photographed at each temperature.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail.

It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

In the present invention, the terms "comprising" or "having ", and the like, specify that the presence of a feature, a number, a step, an operation, an element, a component, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

In the present invention, "Hansen solubility" refers to solubility that reflects the cohesive force (for example, affinity) between a solute and a solvent derived from a molecular structure.

Hereinafter, the present invention will be described in detail.

A method of removing a photoresist according to an embodiment of the present invention includes:

Treating the photoresist-treated semiconductor with an organic solvent to remove the photoresist at a temperature of 110 DEG C or higher.

The step of treating the organic solvent to remove the photoresist may be performed at a temperature of 110 ° C or higher. Specifically, the temperature of the step of treating the organic solvent and removing the photoresist may be in the range of 110 캜 to 200 캜, 115 캜 to 200 캜, 115 캜 to 190 캜, 120 캜 to 185 캜, 125 캜 to 180 캜, 175 ° C, 135 ° C to 170 ° C, or 110 ° C to 170 ° C. It is possible to remove the photoresist residue on the semiconductor as well as the crust generated upon implantation of the photoresist ion by treating the semiconductor with the organic solvent at a high temperature of 110 DEG C or higher.

The photoresist-treated semiconductor may comprise a germanium element (Ge) or a group III-V compound. Specifically, the group III-V compound includes any two or more selected from the group consisting of indium element (In), gallium element (Ga), aluminum element (Al), arsenic element (As) . The method of removing the photoresist according to the present invention can use various kinds of metal semiconductors as described above.

The thickness of the photoresist formed on the photoresist-treated semiconductor may be 0.1 to 20 占 퐉. Specifically, the thickness of the photoresist may be 0.2 to 20 μm, 0.2 to 18 μm, 0.25 to 18 μm, 0.25 to 15 μm, 0.3 to 15 μm, 0.3 to 13 μm, 0.35 to 13 μm, 0.4 to 10 μm or 0.5 to 10 μm. By forming the photoresist in the thickness range described above, the organic solvent can be treated to prevent damage to the substrate and remove the photoresist when removing the photoresist.

Further, the lateral width of the photoresist pattern may be 20 to 100 mu m. Specifically, the lateral width of the photoresist pattern may be 20 to 95 占 퐉, 25 to 95 占 퐉, 30 to 90 占 퐉, 30 to 85 占 퐉, 35 to 80 占 퐉, or 40 to 80 占 퐉.

Further, a dopant can be implanted into the photoresist-processed semiconductor through ion implantation. The dopant may be B (boron), P (phosphorus), or As (arsenic). In addition, the dopant may be added in an ion state upon implantation into a semiconductor. At this time, photoresist and dopant ions can react with each other to form a crust.

Also, the ion implantation dose of the photoresist-treated semiconductor may be between 5 × ^{10 12} and 5 × ^{10 15} atoms · cm ^-2 . Specifically, the ion implantation (ion implantation) dose (dose) is 7.5X10 ¹² to ^{5X10 15 atom · cm -2, 7.5X10} 12 to ^{2.5X10 15 atom · cm -2, 1X10} 13 to about 2.5X10 ¹⁵ atom · cm ^{- 2,} may be 1X10 ¹³ to ^{1X10 14 atom · cm -2, 2.5X10} 13 to 1X10 ¹⁴ atom · cm ^-2 and 2.5X10 ¹³ to 7.5X10 ¹³ atom · cm ^-2. By limiting the dose of the ion implantation to the above-mentioned range, it is possible to remove the photoresist without causing micro-transformation on the semiconductor at the treating temperature of the organic solvent and the organic solvent according to the present invention. In the present invention, the unit of dose (atom · cm ^-2 ) means the number of doping atoms per unit area.

The photoresist removing method according to the present invention can satisfy the following general formula (1).

[Formula 1]

R _a / R _0? 1.2

Here, R _a is the Hansen solubility parameter distance (HSP Distance) of the organic solvent (solvent)

R ₀ is the Hansen solubility parameter distance (HSP Distance) of the photoresist (solute).

The above general formula (1) is an expression derived from the Hansen solubility parameter.

When the R _a / R _o value is less than 1, the affinity between the solute and the solvent is high, and when the R _a / R ₀ value is more than 1, the affinity between the solute and the solvent is low. The organic solvent and the photoresist used in the present invention have an R _a / R ₀ value of 1.2 or less, and the organic solvent and the photoresist have high affinity with each other, so that the organic solvent easily permeates the photoresist. As a result, the photoresist removal efficiency can be improved while preventing damage to the semiconductor.

The Hansen solubility parameter may be represented by the following general formula (2).

[Formula 2]

隆² = 隆_D ² + 隆_P ^{2 +}隆_H ²

Here, 隆 is E / V, E is binding energy, V is molar volume, 隆_D is dispersion parameter, 隆_P is polarity parameter, and 隆_H is hydrogen bonding parameter.

From the Hansen solubility parameter, an Ra value that represents the HSP distance between two molecules and satisfies the following general formula (3) can be obtained.

[Formula 3]

(Ra) ² = 4 (delta _D2 - delta _D1 ) ² + (delta _P2 - delta _P1 ) ² + delta _H2 - delta _H1 ²

The organic solvent used in the method of removing the photoresist according to the present invention may include N-methyl-2-pyrrolidone (NMP), dimethyl sulfoxide (DMSO), benzyl alcohol alcohol, BA) and propylene carbonate (PC). In general, a semiconductor containing germanium (Ge) or group III-V causes damage to the substrate when using a mixture solution of sulfuric acid (SPM) or ozone water as a solvent. However, by treating the organic solvent according to the present invention, the photoresist can be efficiently removed on the semiconductor containing germanium (Ge) or III-V group. In addition, the organic solvent can remove the photoresist injected at a high dose without damaging the substrate. The organic solvent may be at least 90% pure, specifically at least 95%, 96%, 97%, 98% or 99% in order to remove the photoresist injected at a high dose.

The method of removing the photoresist according to the present invention may further include, after the step of removing the photoresist, cleaning the semiconductor from which the photoresist has been removed with ultrapure water.

The step of cleaning with ultra pure water may be performed by washing with ultra-pure water for 10 seconds or more. Specifically, the cleaning time may be 10 seconds to 30 minutes, 10 seconds to 20 minutes, 20 seconds to 20 minutes, 30 seconds to 15 minutes, or 30 seconds to 10 minutes. When the photoresist-treated semiconductor supported on the organic solvent is washed with ultra-pure water for 10 seconds or more, the organic solvent remaining in the semiconductor can be sufficiently removed. Therefore, cleaning with ultra-pure water can prevent the organic solvent from remaining on the semiconductor and damaging the semiconductor substrate.

In the method of removing the photoresist according to the present invention, the step of treating the organic solvent to remove the photoresist may be performed for about 0.5 to about 60 minutes. Specifically, the step of removing the photoresist may be 1 to 60 minutes, 2 to 55 minutes, 2 to 50 minutes, 3 to 45 minutes, 3 to 40 minutes, 4 to 40 minutes, 4 to 35 minutes, or 5 to 30 minutes have.

The method of removing photoresist according to the present invention may further include removing ultrapure water using nitrogen gas after cleaning with ultra pure water.

Hereinafter, the present invention will be described in more detail with reference to the following Examples. However, the scope of the present invention is not limited by the following Examples.

Example 1

A semiconductor including photoresist-processed germanium (Ge) implanted at ⁵ * ¹⁰ < ¹³ > atoms * cm <& quot ^{; 2} > was cut to a width of 1 cm and a length of 0.5 cm to prepare semiconductor samples, (NMP) at 150 ° C for 5 minutes, rinsed in ultrapure water for 30 seconds, and ultrapure water was removed using nitrogen gas to remove the photoresist.

Example 2

5X10 ¹⁴ atom · cm ^- was except that the semiconductor layers containing ion-implanted photoresist processing germanium (Ge) to ^2, and remove the same photoresist as in Example 1.

Example 3

5X10 ¹⁵ atom · cm ^- in the same manner as in Example 1 except that the semiconductor layers containing ion-implanted photoresist processing germanium (Ge) as a ² to remove the photoresist.

Example 4

The photoresist was removed in the same manner as in Example 1, except that dimethyl sulfoxide (DMSO) was used as the organic solvent.

Example 5

5X10 ¹⁴ atom · cm ^- the same manner as in Example 4 except that the semiconductor layers containing ion-implanted photoresist processing germanium (Ge) as a ² to remove the photoresist.

Example 6

5X10 ¹⁵ atom · cm ^- was except that the semiconductor layers containing ion-implanted photoresist processing germanium (Ge) to ^2, and remove the same as Example 4 with the photoresist.

Example 7

The photoresist was removed in the same manner as in Example 1, except that benzyl alcohol (BA) was used as the organic solvent.

Example 8

5X10 ¹⁴ atom · cm ^- the same manner as in Example 7 except that the semiconductor layers containing ion-implanted photoresist processing germanium (Ge) as a ² to remove the photoresist.

Example 9

5X10 ¹⁵ atom · cm ^- was except that the semiconductor ² including the ion-implanted photoresist processing germanium (Ge), and remove the same as Example 7 with the photoresist.

Example 10

The photoresist was removed in the same manner as in Example 1 except that propylene carbonate (PC) was used as an organic solvent.

Example 11

5X10 ¹⁴ atom · cm ^- was except that the semiconductor ² including the ion-implanted photoresist processing germanium (Ge), and remove the same photoresist as in Example 10.

Example 12

5X10 ¹⁵ atom · cm ^- was except that the semiconductor ² including the ion-implanted photoresist processing germanium (Ge), and remove the same photoresist as in Example 10.

Example 13

The photoresist was removed in the same manner as in Example 1, except that a semiconductor containing photoresist-treated germanium (Ge) without ion implantation was used.

Example 14

The photoresist was removed in the same manner as in Example 13 except that dimethyl sulfoxide (DMSO) was used as an organic solvent.

Example 15

The photoresist was removed in the same manner as in Example 13 except that benzyl alcohol (BA) was used as the organic solvent.

Example 16

The photoresist was removed in the same manner as in Example 13, except that propylene carbonate (PC) was used as an organic solvent.

Comparative Example 1

The photoresist was removed in the same manner as in Example 1 except that sulfuric acid and hydrogen peroxide were mixed as a solvent at a molar ratio of 10: 1.78 at a temperature of 25 占 폚 in a sulfuric peroxide mixture (SPM). As a result of analyzing the surface of the semiconductor from which the ultrapure water was removed, it was confirmed that the photoresist on the surface was removed and the surface was damaged.

Comparative Example 2

The procedure of Comparative Example 1 was repeated except that ozonated water (DIO ₃ ) was used as a solvent. As a result of analyzing the surface of the semiconductor from which the ultrapure water was removed, it was confirmed that a photoresist residue was present.

Experimental Example 1

(NMP), dimethylsulfoxide (DMSO), benzyl alcohol (BA), and propylene carbonate (PC), in an organic solvent, in the presence of an ion implantation- And the thickness of the photoresist residue on the semiconductor was measured by varying the temperature of the organic solvent carrying the semiconductor from 30 ° C to 150 ° C at 30 ° C intervals. The results are shown in FIG. ≪ Examples 13 to 16 >

The graph of FIG. 2 is a graph showing the thickness of the photoresist residue according to the temperature of the organic solvent. 2, all of the organic solvents almost completely remove the residues at a temperature of 150 ° C or higher, and dimethylsulfoxide (DMSO) and benzyl alcohol (BA) . In addition, propylene carbonate (PC) showed almost no residue at a temperature of 130 ° C or higher.

Experimental Example 2

In order to confirm the removal efficiency of the photoresist removing method according to the present invention, the degree of removal with respect to the temperature of the organic solvent, specifically, the remaining amount and thickness of the photoresist residue was measured. At this time, the temperature of the organic solvent was changed from 30 占 폚 to 150 占 폚 at 20 占 폚 intervals.

In Examples 6 5X10 ¹⁵ atom · cm ^of-2 were analyzed for the ion implantation the photoresist process photoresist residues thickness intended for semiconductor, including germanium (Ge) as a scanning electron microscope (SEM), the remaining Status Were evaluated by Atomic Force Microscope (AFM). The results are shown in FIG. 3 and FIG.

In addition, the average thickness of the photoresist residue of the semiconductor from which the photoresist was removed by the methods of Examples 1 to 12 was analyzed by a scanning electron microscope (SEM), and the residual was evaluated by an atomic force microscope (AFM). The results are shown in Table 1 below.

Temperature
Dose
(atom cm ^-2 ) 30 ℃ 50 ℃ 70 ℃ 90 ° C 110 ° C 130 ℃ 150 ℃ NMP 5 × 10 ¹³ ○ ○ ○ ○ ○ × × 5 x 10 ¹⁴ ○ ○ ○ ○ ○ × × 5 × 10 ¹⁵ ◎ ◎ ◎ ◎ ◎ ○ × DMSO 5 × 10 ¹³ ○ ○ ○ ○ × × × 5 x 10 ¹⁴ ○ ○ ○ ○ × × × 5 × 10 ¹⁵ ◎ ◎ ◎ ○ × × × BA 5 × 10 ¹³ ○ ○ ○ ○ × × × 5 x 10 ¹⁴ ○ ○ ○ ○ × × × 5 × 10 ¹⁵ ◎ ◎ ◎ ◎ ◎ ○ × PC 5 × 10 ¹³ ○ ○ ○ ○ ○ × × 5 x 10 ¹⁴ ○ ○ ○ ○ ○ × × 5 × 10 ¹⁵ ◎ ◎ ◎ ◎ ◎ ◎ ×

In Table 1,

◎: existence of crust,

?: Presence of residues,

X: means removed.

As shown in FIG. 3 and FIG. 4, when the temperature of the organic solvent is 110.degree. C. or more, it can be confirmed that the photoresist has been completely removed. Specifically, referring to FIG. 3, a photoresist having a thickness of 1.2 .mu.m was confirmed at 30.degree. C., and it was confirmed that the thickness of the photoresist residue remained at 9 nm at 90.degree. On the other hand, it was confirmed that no photoresist residue remained at 130 占 폚.

Also, referring to FIG. 4, it can be seen that the crust exists in the ion-implanted photoresist at 30 ° C., and the photoresist residue remained at 90 ° C. On the other hand, it was confirmed that no photoresist residue remained at 130 占 폚.

As shown in Table 1, when N-methyl-2-pyrrolidone was used as the organic solvent, the ion-implanted dose of ⁵ × ^{10 13} atoms · cm ^-2 and 5 × ^{10 14} atoms · cm ^-2 And the photoresist residue was removed at a temperature of 150 ° C or higher in the ion-implanted dose of ⁵ × ^{10 15} atoms · cm ^-2 . In the case of using dimethylsulfoxide as the organic solvent, the ion implantation dose of ⁵ × ^{10 13} atoms · cm ^-2 , 5 × ^{10 14} atoms · cm ^-2 and 5 × ^{10 15} atoms · cm ^-2 , The residue was removed. In the case of using benzyl alcohol, photoresist residues were removed at a temperature of 110 ° C or higher in an ion-implanted dose of ⁵ × ^{10 13} atoms · cm ^-2 and 5 × ^{10 14} atoms · cm ^-2 , and a dose of 5 × ^{10 15} atoms · cm ^-2 Lt; RTI ID = 0.0 > 150 C < / RTI > In the case of using the propylene kaboneyiteueul, 5X10 ¹³ atom · cm ^-2 and 5X10 ¹⁴ atom · cm ^-2 implanted dose (dose) was in the photoresist residue was removed from the more than 130 ℃ temperature, 5X10 ¹⁵ atom · cm ^-2 of It was confirmed that the photoresist residue was removed at a temperature of 150 ° C or higher in the ion-implanted dose. As a result of the above experimental results, the temperature at which the residue can be removed is increased when the ion-implanted dose is increased, and the organic solvent having high photoresist removal efficiency has a dimethyl sulfoxide Seed.

Claims (7)

And removing the photoresist by treating the photoresist-treated semiconductor with an organic solvent at a temperature of 110 占 폚 or higher.
The method according to claim 1,
A photoresist removing method satisfying the following general formula 1:
[Formula 1]
R _a / R _0? 1.2
Here, R _a is the Hansen solubility parameter distance (HSP Distance) of the organic solvent (solvent)
R ₀ is the Hansen solubility parameter distance (HSP Distance) of the photoresist (solute).
The method according to claim 1,
The organic solvent is selected from the group consisting of N-methyl-2-pyrrolidone (NMP), dimethyl sulfoxide (DMSO), benzyl alcohol (BA), and propylene carbonate PC). ≪ / RTI >
The method according to claim 1,
After the step of removing the photoresist,
Further comprising the step of cleaning the semiconductor from which the photoresist has been removed with ultrapure water.
The method according to claim 1,
Wherein removing the photoresist is performed for 30 seconds to 60 minutes.
The method according to claim 1,
Wherein the photoresist-treated semiconductor comprises a germanium element (Ge) or a group III-V compound.
5. The method of claim 4,
After the step of washing with ultra pure water,
And removing ultrapure water by using nitrogen gas.

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