Plasma chamber for wafer etching and method of wafer etching using the plasma chamber - Patents.com

Abstract

The present invention relates to a plasma chamber for etching a wafer and a method for etching a wafer using the plasma chamber. The plasma chamber of the present invention includes a housing having a reaction space therein for etching a wafer using plasma; a base plate provided inside the housing and on which the wafer is placed; and a pressure adjusting unit for adjusting a pressure inside the housing, the pressure adjusting unit adjusting the pressure inside the housing to 50 to 150 mTorr. The method for etching a wafer using the plasma chamber of the present invention includes a pressure adjusting step of adjusting the pressure inside the housing to 50 to 150 mTorr via the pressure adjusting unit; and a source power adjusting step of adjusting a source power of the plasma source to 300 to 1000 W via the plasma source.

Description

[Technical field]

[0001] The present invention relates to a plasma chamber for etching a wafer and a method for etching a wafer using the plasma chamber, and more particularly to a plasma chamber for etching a wafer and a method for etching a wafer using the plasma chamber, which can improve selectivity while maintaining a high etch rate. [Background technology]

[0002] In general, it is very important to ensure uniformity in a semiconductor manufacturing process, and the uniformity of a semiconductor can be ensured or controlled in an etching process among the semiconductor manufacturing processes.

[0003] The semiconductor etching process may be performed inside a plasma chamber, which generates plasma within a reaction space therein and performs the semiconductor etching process using the plasma.

[0004] A plasma source for generating plasma is provided at the top of the plasma chamber. Representative examples of the plasma source include a capacitively coupled plasma (CCP) source and an inductively coupled plasma (ICP) source.

[0005] A capacitively coupled plasma (CCP) source uses an electric field and generally allows etching to proceed at a slightly higher pressure than an inductively coupled plasma (ICP). Although the etch rate is slow, the CCP source is known to have excellent selectivity characteristics and process repeatability.

[0006] However, the capacitively coupled plasma (CCP) source has a plasma density non-uniformity characteristic in which the plasma density at the center of the wafer is relatively higher than the plasma density at the edge of the wafer, and since the overall plasma density is relatively low, there is a problem in that high RF power must be applied to increase the plasma density.

[0007] Inductively coupled plasma (ICP) uses an induced magnetic field and has the advantage of a higher overall plasma density compared to capacitively coupled plasma (CCP) sources. Although ICP can increase the etching rate at a lower pressure than CCP sources, the plasma density at the center of the wafer is relatively higher than that at the edge of the wafer, resulting in a high etching rate but low selectivity and poor process repeatability.

[0008] As such, conventional plasma sources such as capacitively coupled plasma (CCP) and inductively coupled plasma (ICP) have the problem that it is difficult to simultaneously increase the etching rate and selectivity, and it has been recognized that there is a trade-off between the etching rate and the selectivity. Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention relates to a plasma chamber for wafer etching that can improve selectivity while maintaining a high etch rate, and a method for etching a wafer using the plasma chamber. [Means for solving the problem]

[0010] In order to solve the above-mentioned problems, the plasma chamber for wafer etching of the present invention is a plasma chamber that forms plasma for etching a wafer, and includes: a housing having a reaction space therein for etching a wafer via plasma; a base plate that is provided inside the housing and on which the wafer is placed; and a pressure adjusting unit that adjusts the pressure inside the housing; wherein the pressure adjusting unit adjusts the pressure inside the housing to 50 to 150 mTorr. In order to solve the above problems, the plasma chamber for wafer etching of the present invention further includes a plasma source provided on an upper portion of the housing to generate plasma inside the housing, and the source power of the plasma source may be 300 to 1000 W.

[0011] In order to solve the above problems, the plasma source of the plasma chamber for wafer etching of the present invention can be configured so that the driving frequency of the plasma source is the same as the collision frequency between particles inside the housing.

[0012] In order to solve the above-mentioned problems, the plasma formed in the reaction space of the housing of the plasma chamber for wafer etching of the present invention has a density of cubic centimeters (cm -3 ) can be 5E10 to 5E11.

[0013] In order to solve the above-mentioned problems, the plasma chamber for wafer etching of the present invention further includes a temperature control unit that controls the temperature of the base plate, and the temperature control unit can control the temperature of the base plate to 20 to 50 degrees (°C).

[0014] In order to solve the above-mentioned problems, the plasma chamber for wafer etching of the present invention further includes a bias RF source connected to the base plate and capable of applying a bias to the base plate, and the bias power of the bias RF source may be 1000 to 3000 W.

[0015] In order to solve the above-mentioned problems, the plasma formed in the reaction space of the housing of the plasma chamber for wafer etching of the present invention includes ions and radicals, and the wafer can be etched by a synergy effect of the ions and the radicals.

[0016] In order to solve the above-mentioned problems, the plasma formed in the reaction space of the housing of the plasma chamber for wafer etching of the present invention includes electrons, and the electron energy relaxation length of the electrons may be smaller than the diameter of the housing.

[0017] In order to solve the above-mentioned problems, the present invention provides a wafer etching method using a plasma chamber, which etches a wafer through a plasma chamber including a housing having a reaction space therein for etching a wafer through plasma, a base plate provided inside the housing and on which the wafer is placed, a pressure adjusting unit for adjusting a pressure inside the housing, and a plasma source provided on an upper portion of the housing and forming plasma inside the housing, the method comprising the steps of: adjusting a pressure inside the housing to 50 to 150 mTorr through the pressure adjusting unit; and adjusting a source power of the plasma source to 300 to 1000 W through the plasma source.

[0018] In order to solve the above-mentioned problems, the wafer etching method using the plasma chamber of the present invention includes a frequency adjusting step of adjusting a driving frequency of the plasma source, and in the frequency adjusting step, the driving frequency of the plasma source can be adjusted so that the driving frequency of the plasma source is equal to a collision frequency between particles inside the housing.

[0019] In the wafer etching method using the plasma chamber of the present invention for solving the above-mentioned problems, the density of the plasma formed in the reaction space of the housing is cubic centimeters (cm -3 ) can be 5E10 to 5E11.

[0020] In order to solve the above-mentioned problems, the plasma chamber of the wafer etching method using a plasma chamber of the present invention may further include a temperature adjusting step of adjusting the temperature of the base plate to 20 to 50 degrees (°C) via the temperature adjusting unit, wherein the plasma chamber includes a temperature adjusting unit that adjusts the temperature of the base plate to 20 to 50 degrees (°C).

[0021] In order to solve the above-mentioned problems, the plasma chamber of the wafer etching method using the plasma chamber of the present invention may further include a bias RF source connected to the base plate and capable of applying a bias to the base plate, and a bias power adjusting step of adjusting a bias power of the bias RF source to 1000 to 3000 W via the bias RF source.

[0022] In accordance with the present invention, in order to solve the above-mentioned problems, the plasma formed in the reaction space of the housing of the wafer etching method using the plasma chamber includes ions and radicals, and the wafer can be etched by a synergy effect between the ions and the radicals.

[0023] In the wafer etching method using the plasma chamber of the present invention to solve the above-mentioned problems, the plasma formed in the reaction space of the housing contains electrons, and the electron energy relaxation length of the electrons may be smaller than the diameter of the housing. Effect of the Invention

[0024] The present invention relates to a plasma chamber for wafer etching and a wafer etching method using the plasma chamber, and has an advantage in that the pressure inside the chamber is relatively higher than that of a conventional chamber, thereby maintaining a high etch rate while improving the PR selectivity.

[0025] Also, the present invention has the advantage that a high etch rate and high PR selectivity can be obtained while using lower power than the conventional chambers in the plasma source and bias RF source. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 illustrates ions and radicals etching a wafer. [Diagram 2] FIG. 1 illustrates a plasma chamber for wafer etching according to an embodiment of the present invention. [Diagram 3] 1A to 1C are diagrams illustrating a wafer etching method using a plasma chamber according to an embodiment of the present invention. [Figure 4] FIG. 2 illustrates a source power adjusting step and a frequency adjusting step according to an embodiment of the present invention. [Diagram 5]FIG. 11 is a diagram comparing the etching rate (ER), selectivity, chuck temperature (Chuck temp), source power (S / P), bias power (B / P), and pressure for a plasma chamber according to an embodiment of the present invention, an inductively coupled plasma (ICP), and a capacitively coupled plasma (CCP). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] The present specification explains the principles of the present invention and discloses embodiments so as to clarify the scope of the present invention and enable those skilled in the art to practice the present invention. The disclosed embodiments may be embodied in various forms.

[0028] The terms "include" or "may include" as used in various embodiments of the present invention indicate the presence of the disclosed feature, operation, or component, and do not limit the presence of one or more additional features, operations, or components. Furthermore, in various embodiments of the present invention, the terms "include" or "have" as used herein are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and should not be understood as precluding the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0029] When an element is referred to as being "connected or coupled" to another element, it should be understood that the element may be directly connected or coupled to the other element, but that there may be another element between the element and the other element. On the other hand, when an element is referred to as being "directly connected" or "directly coupled" to another element, it should be understood that there is no another element between the element and the other element.

[0030] The terms "first", "second", etc., used in this specification may be used to describe various components, but the components should not be limited by the terms. The terms are used only to distinguish one component from another component.

[0031] The present invention relates to a plasma chamber for wafer etching and a method for etching a wafer using the plasma chamber, and more particularly to a plasma chamber for wafer etching and a method for etching a wafer using the plasma chamber, which can improve selectivity while maintaining a high etch rate.

[0032] 1, plasma is largely composed of electrons, ions 21, and radicals 22. In a detailed look at the conventional method of etching a wafer using plasma, the dominant species during the plasma etching process is either ions or radicals.

[0033] Specifically, in the conventional method of etching a wafer via plasma, metal etch primarily uses radicals, while oxide etch primarily uses ions.

[0034] In the plasma chamber for wafer etching and the method for etching a wafer using the plasma chamber according to the embodiment of the present invention, the dominant species during the plasma etching process is not formed of either ions or radicals, but rather, ions 21 and radicals 22 can be used simultaneously.

[0035] In other words, the plasma chamber for wafer etching and the wafer etching method using the plasma chamber according to the embodiment of the present invention use a process region in which ions 21 and radicals 22 act together to produce a synergy effect, rather than performing an ion-dominated reaction or a radical-dominated reaction during the plasma etching process.

[0036] More specifically, the plasma chamber for wafer etching and the method of etching a wafer using the plasma chamber according to the embodiment of the present invention can improve selectivity while maintaining a high etch rate by using ions and radicals simultaneously and by using a synergy effect caused by resonance between the ions and radicals.

[0037] The plasma chamber for wafer etching and the wafer etching method using the plasma chamber according to the embodiments of the present invention may solve problems and improve upon the conventional method using an inductively coupled plasma (ICP) source.

[0038] The plasma chamber for etching a wafer and the method for etching a wafer using the plasma chamber according to the embodiment of the present invention may be synergistic resonance ICP (SRICP) that utilizes a synergy effect generated by a resonance state.

[0039] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A plasma chamber for etching a wafer and a method of etching a wafer using the plasma chamber according to an embodiment of the present invention can adjust the conditions of the plasma chamber to simultaneously use ions and radicals.

[0040] The plasma chamber for wafer etching and the method for etching a wafer using the plasma chamber according to the embodiment of the present invention can adjust the pressure inside the chamber, the temperature of the chuck, the source power of the plasma source, the driving frequency of the plasma source, the plasma density inside the chamber, the bias power of the bias RF source, etc., and the plasma chamber for wafer etching and the method for etching a wafer using the plasma chamber according to the embodiment of the present invention can use ions and radicals simultaneously by changing the above conditions in the plasma chamber.

[0041] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0042] Referring to FIG. 2, a plasma chamber 100 for wafer etching according to an embodiment of the present invention includes a housing 110, a base plate 111, and a pressure control unit 120. The housing 110 includes a base plate 111 and a pressure control unit 120. The base plate 111 is a pressure adjusting unit.

[0043] The housing 110 has a reaction space therein for etching the wafer 10 using plasma. The housing 110 may be an outer chamber wall of the plasma chamber 100 for etching a wafer according to an embodiment of the present invention, and has a space therein. When the wafer 10 is loaded into the housing 110, the wafer 10 may be etched by the plasma generated inside the housing 110.

[0044] The base plate 111 is provided inside the housing 110 and supports the wafer 10. The base plate 111 may be a plate provided inside the housing 110 and supports the wafer 10.

[0045] More specifically, the base plate 111 may be a wafer chuck that supports the wafer 10 by placing the wafer 10 thereon, and when the wafer 10 is placed on the base plate 111, etching of the wafer 10 may proceed.

[0046] The pressure adjusting unit 120 adjusts the pressure inside the housing 110. The pressure adjusting unit 120 may be a pressure adjusting device that adjusts the pressure inside the housing 110, and the pressure adjusting unit 120 may be a device having various configurations as long as it can adjust the pressure inside the housing 110.

[0047] According to an embodiment of the present invention, the pressure adjusting unit 120 can adjust the pressure inside the housing 110 to 50 to 150 mTorr. As described above, the plasma chamber for wafer etching according to an embodiment of the present invention can use ions 21 and radicals 22 simultaneously.

[0048] In the plasma chamber for wafer etching according to the embodiment of the present invention, the pressure inside the housing 110 can be adjusted to 50 to 150 mTorr through the pressure adjusting unit 120 in order to simultaneously use ions 21 and radicals 22.

[0049] When ions 21 and radicals 22 are used simultaneously, if the pressure inside the housing 110 is less than 50 mTorr, there is a risk of the etching rate decreasing. Conversely, if the pressure inside the housing 110 is greater than 150 mTorr, the reaction between particles becomes too frequent, shortening the reaction time, and the etching rate may decrease.

[0050] Therefore, in the plasma chamber for wafer etching according to the embodiment of the present invention, it is preferable that the pressure inside the housing 110 is adjusted to 50 to 150 mTorr through the pressure adjusting unit 120 .

[0051] The plasma chamber for wafer etching according to the embodiment of the present invention may further include a plasma source 130 disposed on the upper portion of the housing 110 to generate plasma within the housing 110 .

[0052] The plasma source 130 can generate plasma and may include a coil 131 and an RF power generator 132. According to an embodiment of the present invention, the source power of the plasma source 130 may be adjusted to 300 to 1000W.

[0053] If the source power generated by the plasma source 130 is less than 300W, the etching rate decreases. Therefore, it is preferable that the source power generated by the plasma source 130 is greater than 300W.

[0054] As described above, the plasma chamber for wafer etching according to an embodiment of the present invention adjusts the pressure inside the housing 110 to 50 to 150 mTorr via the pressure adjusting unit 120, so that the pressure inside the housing 110 can be higher than that of a conventional plasma chamber.

[0055] If the source power generated by the plasma source 130 is greater than 1000 W, the plasma density may become excessively high due to the relatively high internal pressure of the housing 110. If the plasma density becomes excessively high, the reaction between particles becomes too frequent, shortening the reaction time and decreasing the etching rate.

[0056] Therefore, in the plasma chamber for wafer etching according to the embodiment of the present invention, it is preferable that the source power of the plasma source 130 is adjusted to 300 to 1000W.

[0057] In the plasma source 130 of the plasma chamber for wafer etching according to the embodiment of the present invention, it is preferable to set the driving frequency of the plasma source 130 to be the same as the collision frequency between particles inside the housing 110 .

[0058] As described above, the plasma chamber for wafer etching according to the embodiment of the present invention can improve selectivity while maintaining a high etch rate by using ions and radicals simultaneously and by using a synergy effect caused by resonance between the ions and radicals.

[0059] In the plasma chamber for wafer etching according to an embodiment of the present invention, it is preferable to set the driving frequency of the plasma source 130 to be the same as the collision frequency between particles inside the housing 110 in order to induce resonance occurring between ions and radicals.

[0060] The collision frequency between particles inside the housing 110 can be determined by the product of the number of particles per unit volume and the rate constant for the collision reaction. The plasma source 130 according to the embodiment of the present invention can first analyze data on the collision frequency, and then adjust the driving frequency of the plasma source 130 to be the same as the collision frequency between particles inside the housing 110 based on the data.

[0061] A plasma chamber for wafer etching according to an embodiment of the present invention may include a collision frequency analyzer for analyzing the collision frequency between particles generated inside the housing 110, and the plasma source 130 may receive data from the collision frequency analyzer to adjust the driving frequency of the plasma source 130.

[0062] According to an embodiment of the present invention, the driving frequency of the plasma source 130 can be adjusted via the RF power generator 132 provided in the plasma source 130 .

[0063] According to an embodiment of the present invention, the density of the plasma formed in the reaction space of the housing 110 is 1 / 3 cubic centimeter (cm -3 ) is preferably 5E10 to 5E11.

[0064] The density of the plasma formed in the reaction space of the housing 110 is 1 / 3 cubic centimeter (cm -3 If the difference is less than 5E10 per 1000 sq. m, the target etching rate cannot be obtained.

[0065] On the other hand, the density of the plasma formed in the reaction space of the housing 110 is 1 / 3 cubic centimeter (cm -3 ) is greater than 5E11, the ions 21 and the radicals 22 may separate, adversely affecting the selectivity.

[0066] That is, in the plasma chamber for wafer etching according to the embodiment of the present invention, the density of the plasma formed in the reaction space of the housing 110 is set to cubic centimeters (cm 3 ) in order to improve the etching rate and the selectivity by simultaneously using ions 21 and radicals 22. -3 ) is formed with 5E10 to 5E11.

[0067] The density of the plasma formed in the reaction space of the housing 110 according to the embodiment of the present invention can be adjusted by the plasma source 130. Specifically, a plasma density suitable for simultaneously using ions 21 and radicals 22 can be formed inside the housing 110 through the plasma source 130.

[0068] Referring to FIG. 2, the plasma chamber 100 for wafer etching according to an embodiment of the present invention may further include a temperature control unit 140 for controlling the temperature of the base plate 111 .

[0069] The temperature control unit 140 may be a temperature control device connected to the base plate 111 and capable of controlling the temperature of the base plate 111. The temperature control unit 140 may include various configurations as long as it can control the temperature of the base plate 111.

[0070] By adjusting the temperature of the base plate 111 through the temperature adjustment unit 140, the temperature of the wafer 10 placed on the base plate 111 can be adjusted.

[0071] According to an embodiment of the present invention, it is preferable that the temperature control unit 140 controls the temperature of the base plate 111 to 20 to 50 degrees (°C). Ions 21 are independent of the temperature of the wafer 10, but radicals 22 may sensitively react to the temperature of the wafer 10.

[0072] Therefore, if the temperature of the base plate 111 is lower than 20° C., the temperature of the wafer 10 decreases, which may limit the activity of radicals. Also, if the temperature of the base plate 111 is higher than 50° C., there is a risk of burning.

[0073] In accordance with an embodiment of the present invention, the wafer 10 is preferably set to a temperature in the range of room temperature (20 to 50°C) in order to react simultaneously with the ions 21 and radicals 22, and therefore, it is preferable to adjust the temperature of the base plate 111 to 20 to 50°C via the temperature control unit 140.

[0074] Referring to FIG. 2, the plasma chamber 100 for wafer etching according to an embodiment of the present invention may further include a bias RF source 150 connected to the base plate 111 and capable of applying a bias to the base plate 111.

[0075] The bias RF source 150 can apply a bias to the base plate 111 to apply a bias to the plasma during an etching process.

[0076] According to an embodiment of the present invention, the bias power of the bias RF source 150 is preferably adjusted to 1000 to 3000 W. The bias power has a direct effect on the ions 21.

[0077] If the bias power of the bias RF source 150 is less than 1000 W, the activity of the ions 21 is restricted and the radicals 22 become predominantly active, so that the synergy effect between the ions 21 and the radicals 22 cannot be expected.

[0078] On the other hand, if the bias power of the bias RF source 150 is greater than 3000 W, the ions become predominantly active, and the synergy effect between the ions 21 and the radicals 22 cannot be expected.

[0079] As a result, in the plasma chamber 100 for wafer etching according to an embodiment of the present invention, the bias power of the bias RF source 150 must be adjusted to 1000 to 3000 W in order to generate a synergy effect between the ions 21 and the radicals 22.

[0080] According to an embodiment of the present invention, the plasma formed in the reaction space of the housing 110 includes ions 21 and radicals 22, and the wafer 10 can be etched by a synergistic effect of the ions 21 and the radicals 22.

[0081] Furthermore, according to an embodiment of the present invention, the plasma formed in the reaction space of the housing 110 may include electrons, and an electron energy relaxation length (EERL) of the electrons may be smaller than a diameter of the housing.

[0082] The plasma chamber 100 for wafer etching according to an embodiment of the present invention can be performed in a local electron kinetics process region. Conventional etching processes are performed in a nonlocal electron kinetics process region where the electron energy relaxation length (EERL) is always larger than the diameter of the process chamber.

[0083] However, the plasma chamber 100 for wafer etching according to an embodiment of the present invention may be operated in a local electron kinetics process region in which the electron energy relaxation length (EERL) is smaller than the diameter of the process chamber (the diameter of the housing 110).

[0084] As a result, the plasma chamber 100 for wafer etching according to an embodiment of the present invention can have a higher plasma density at the ends of the housing 110 than at the center of the housing 110, and the etching rate can also be higher at the ends of the housing 110 than at the center of the housing 110.

[0085] In conventional etching processes, a problem of weak etching at the edge of a wafer (low edge yield problem) can occur, but the plasma chamber 100 for wafer etching according to an embodiment of the present invention is able to prevent the occurrence of this problem by forming the etching rate at the edge of the housing 110 to be higher than that at the center of the housing 110.

[0086] In addition, in the conventional etching process, in order to solve the problem of weak etching at the edge of the wafer (low edge yield problem), an independent RF power is applied or a heater, a lift device to prevent corrosion of the edge ring, etc. are used.

[0087] However, in the plasma chamber 100 for wafer etching according to an embodiment of the present invention, the etching rate at the edge of the housing 110 is higher than that at the center of the housing 110, so that a separate device is not required, which has the advantage of reducing manufacturing costs and improving yields.

[0088] The wafer etching method using the plasma chamber according to the embodiment of the present invention relates to a method of etching the wafer 10 through the plasma chamber 100 for wafer etching according to the embodiment of the present invention described above.

[0089] In the above description, the plasma chamber 100 for etching a wafer according to an embodiment of the present invention has been described in detail. Therefore, a detailed description of the plasma chamber 100 for etching a wafer according to an embodiment of the present invention will be omitted below.

[0090] Referring to FIG. 3, the method for etching a wafer using a plasma chamber according to the embodiment of the present invention includes a pressure adjusting step (S110) and a source power adjusting step (S120).

[0091] The pressure adjusting step (S110) is a step of adjusting the pressure inside the housing 110 to 50 to 150 mTorr through the pressure adjusting part 120.

[0092] According to an embodiment of the present invention, when ions 21 and radicals 22 are used simultaneously, if the pressure inside the housing 110 is less than 50 mTorr, there is a risk of the etching rate decreasing. On the other hand, if the pressure inside the housing 110 is greater than 150 mTorr, the reaction between particles becomes too frequent, shortening the reaction time and decreasing the etching rate.

[0093] Therefore, in the pressure adjusting step (S110), it is preferable to adjust the pressure inside the housing 110 to 50 to 150 mTorr through the pressure adjusting part 120.

[0094] The source power adjusting step (S120) is a step of adjusting the source power of the plasma source 130 to 300 to 1000 W via the plasma source 130.

[0095] If the source power generated by the plasma source 130 is less than 300W, the etching rate decreases. Therefore, it is preferable that the source power generated by the plasma source 130 is greater than 300W.

[0096] As described above, since the pressure inside the housing 110 is adjusted to 50 to 150 mTorr through the pressure adjusting unit 120 in the pressure adjusting step S110, the internal pressure of the housing 110 may be higher than that of a conventional plasma chamber.

[0097] If the source power generated by the plasma source 130 is greater than 1000 W, the plasma density may become excessively high due to the relatively high internal pressure of the housing 110. If the plasma density becomes excessively high, the reaction between particles becomes too frequent, shortening the reaction time and decreasing the etching rate.

[0098] Therefore, in the source power adjusting step (S120), it is preferable to adjust the source power of the plasma source 130 to 300 to 1000W.

[0099] Referring to FIG. 4, the method for etching a wafer using a plasma chamber according to the embodiment of the present invention may include a frequency adjusting step (S121) of adjusting a driving frequency of the plasma source 130.

[0100] In the frequency adjusting step (S121), the driving frequency of the plasma source 130 may be adjusted so that the driving frequency of the plasma source 130 is equal to the collision frequency between particles inside the housing 110.

[0101] As described above, the plasma chamber 100 for wafer etching according to an embodiment of the present invention is capable of improving selectivity while maintaining a high etch rate through a synergy effect generated by resonance between the ions and radicals while simultaneously using ions and radicals.

[0102] According to an embodiment of the present invention, in order to induce a resonance state occurring between ions and radicals, it is preferable to set the driving frequency of the plasma source 130 to be the same as the collision frequency between particles inside the housing 110.

[0103] The collision frequency between particles inside the housing 110 can be determined by the product of the number of particles per unit volume and the rate constant for the collision reaction. The plasma source 130 according to the embodiment of the present invention can first analyze data on the collision frequency, and then adjust the driving frequency of the plasma source 130 to be the same as the collision frequency between particles inside the housing 110 based on the data.

[0104] The plasma chamber for wafer etching according to the embodiment of the present invention may include a collision frequency analyzer for analyzing a collision frequency between particles generated within the housing 110 .

[0105] The frequency adjusting step (S121) according to an embodiment of the present invention is a step of receiving data from the collision frequency analysis unit and adjusting the driving frequency of the plasma source 130 to be the same as the collision frequency between particles inside the housing 110.

[0106] According to an embodiment of the present invention, the density of the plasma formed in the reaction space of the housing 110 is 1 / 3 cubic centimeter (cm -3 ) is preferably 5E10 to 5E11.

[0107] The density of the plasma formed in the reaction space of the housing 110 is 1 / 3 cubic centimeter (cm -3 If the difference is less than 5E10 per 1000 sq. m, the target etching rate cannot be obtained.

[0108] In contrast, the density of the plasma formed in the reaction space of the housing 110 is 1 / 3 cubic centimeter (cm -3 ) is greater than 5E11, the ions 21 and the radicals 22 may separate, adversely affecting the selectivity.

[0109] That is, in the plasma chamber for wafer etching according to the embodiment of the present invention, the density of the plasma formed in the reaction space of the housing 110 is set to cubic centimeters (cm 3 ) in order to improve the etching rate and the selectivity by simultaneously using the ions 21 and the radicals 22. -3 ) is formed with 5E10 to 5E11.

[0110] According to an embodiment of the present invention, the density of the plasma formed in the reaction space of the housing 110 may be adjusted in the source power adjusting step S120. In the source power adjusting step S120, the source power of the plasma source 130 is adjusted to adjust the density of the plasma formed in the reaction space of the housing 110 to 100 cubic centimeters (cm -3 ) can be formed at 5E10 to 5E11.

[0111] Referring to FIG. 3, the wafer etching method using a plasma chamber in an embodiment of the present invention may further include a temperature adjusting step (S130) of adjusting the temperature of the base plate 111 to 20 to 50 degrees (°C) via the temperature adjusting unit 140.

[0112] The temperature control unit 140 may be a temperature control device connected to the base plate 111 and capable of controlling the temperature of the base plate 111. By controlling the temperature of the base plate 111 through the temperature control unit 140, the temperature of the wafer 10 placed on the base plate 111 can be controlled. According to an embodiment of the present invention, in the temperature adjusting step (S130), it is preferable to adjust the temperature of the base plate 111 to 20 to 50 degrees (°C). Ions 21 are independent of the temperature of the wafer 10, but radicals 22 may sensitively react to the temperature of the wafer 10.

[0113] Therefore, if the temperature of the base plate 111 is lower than 20° C., the temperature of the wafer 10 decreases, which may limit the activity of radicals. Also, if the temperature of the base plate 111 is higher than 50° C., there is a risk of burning.

[0114] In accordance with an embodiment of the present invention, it is preferable to set the temperature of the wafer 10 in the room temperature range (20 to 50°C) in order to react simultaneously with the ions 21 and radicals 22. To this end, in the temperature control step (S130), the temperature of the base plate 111 can be controlled to 20 to 50°C via the temperature control unit 140.

[0115] Referring to FIG. 3, the wafer etching method using a plasma chamber in an embodiment of the present invention may further include a bias power adjusting step (S140) of adjusting the bias power of the bias RF source 150 to 1000 to 3000 W via the bias RF source 150.

[0116] The bias RF source 150 can apply a bias to the base plate 111 to apply a bias to the plasma during an etching process.

[0117] The bias power may have a direct effect on the ions 21. If the bias power of the bias RF source 150 is less than 1000 W, the activity of the ions 21 is restricted and the radicals 22 are allowed to dominate the activity, so that a synergy effect between the ions 21 and the radicals 22 cannot be expected.

[0118] On the other hand, if the bias power of the bias RF source 150 is greater than 3000 W, the ions become predominantly active, and the synergy effect between the ions 21 and the radicals 22 cannot be expected.

[0119] Therefore, in order to generate a synergy effect between the ions 21 and the radicals 22, the bias power of the bias RF source 150 may be adjusted to 1000 to 3000 W in the bias power adjusting step S140.

[0120] In the embodiment of the present invention, the pressure adjusting step (S110), the source power adjusting step (S120), the frequency adjusting step (S121), the temperature adjusting step (S130), and the bias power adjusting step (S140) of the wafer etching method using a plasma chamber do not need to be performed in order, and each process can be performed regardless of the order.

[0121] In addition, the pressure adjusting step (S110), the source power adjusting step (S120), the frequency adjusting step (S121), the temperature adjusting step (S130), and the bias power adjusting step (S140) of the wafer etching method using a plasma chamber according to an embodiment of the present invention may be performed simultaneously.

[0122] As described above, the plasma chamber for wafer etching and the method of etching a wafer using the plasma chamber according to the embodiment of the present invention can adjust the pressure inside the housing 110 through the pressure adjustment unit 120, adjust the source power through the plasma source 130, adjust the temperature of the base plate 111 through the temperature adjustment unit 140, and adjust the bias power through the bias RF source 150.

[0123] The plasma chamber for etching a wafer and the method for etching a wafer using the plasma chamber according to the embodiment of the present invention can improve selectivity while maintaining a high etch rate by simultaneously using ions 21 and radicals 22 to generate a synergy effect by controlling the pressure inside the housing 110, the source power, the temperature of the wafer, and the temperature of the bias power.

[0124] According to an embodiment of the present invention, the plasma formed in the reaction space of the housing 110 includes ions 21 and radicals 22, and the wafer 10 can be etched by a synergistic effect of the ions 21 and the radicals 22.

[0125] Furthermore, according to an embodiment of the present invention, the plasma formed in the reaction space of the housing 110 may include electrons, and an electron energy relaxation length (EERL) of the electrons may be smaller than a diameter of the housing.

[0126] The plasma chamber 100 for wafer etching according to an embodiment of the present invention can be performed in a local electron kinetics process region where the electron energy relaxation length (EERL) is smaller than the diameter of the process chamber (the diameter of the housing 110), unlike conventional etching methods which are performed in a nonlocal electron kinetics process region where the electron energy relaxation length (EERL) is larger than the diameter of the process chamber.

[0127] As a result, the plasma chamber 100 for wafer etching according to an embodiment of the present invention can have a higher plasma density at the ends of the housing 110 than at the center of the housing 110, and the etching rate can also be higher at the ends of the housing 110 than at the center of the housing 110.

[0128] The plasma chamber 100 for wafer etching according to an embodiment of the present invention can solve the problem of weak etching at the edge of the wafer (low edge yield problem) by forming the etching rate at the edge of the housing 110 to be higher than that at the center of the housing 110, and has the advantage of not requiring the use of a separate device to solve the problem.

[0129] In FIG. 5, ER (A / min) is the etch rate, S / P (W) is the source power, B / P (W) is the bias power, Chuck temp (°C) is the temperature of the base plate 111, ICP is inductively coupled plasma, and CCP is capacitively coupled plasma.

[0130] Referring to FIG. 5, the plasma chamber for wafer etching and the wafer etching method using the plasma chamber according to an embodiment of the present invention can improve the PR selectivity while maintaining a high etch rate by forming a higher pressure than conventional capacitively coupled plasma (CCP) and inductively coupled plasma (ICP).

[0131] In addition, the plasma chamber for wafer etching and the wafer etching method using the plasma chamber according to the embodiments of the present invention can obtain a high etch rate and high PR selectivity while using lower power than conventional capacitively coupled plasma (CCP) and inductively coupled plasma (ICP). The plasma chamber for wafer etching according to an embodiment of the present invention may include a control unit that controls the operation of the pressure control unit 120, the plasma source 130, the RF power generator 132, the temperature control unit 140, and the bias RF source 150.

[0132] According to an embodiment of the present invention, the pressure control unit 120, the plasma source 130, the RF power generator 132, the temperature control unit 140, and the bias RF source 150 are controlled in operation via the control unit, so that a condition can be created in which the ions 21 and the radicals 22 can be used simultaneously.

[0133] In addition, the pressure adjusting step (S110), the source power adjusting step (S120), the frequency adjusting step (S121), the temperature adjusting step (S130), and the bias power adjusting step (S140) of the wafer etching method using a plasma chamber according to an embodiment of the present invention may be performed under control via the control unit.

[0134] The plasma chamber for wafer etching and the method for wafer etching using the plasma chamber according to the above-described embodiments of the present invention have the following advantages.

[0135] The plasma chamber for wafer etching and the method for etching a wafer using the plasma chamber according to the embodiment of the present invention have the advantage that the pressure inside the chamber is relatively high compared to that of a conventional chamber, thereby maintaining a high etch rate while improving the PR selectivity.

[0136] In addition, the plasma chamber for wafer etching and the wafer etching method using the plasma chamber according to the embodiment of the present invention have the advantage that a high etch rate and high PR selectivity can be obtained while using lower power than conventional chambers due to the plasma source and bias RF source.

[0137] The plasma chamber for wafer etching and the wafer etching method using the plasma chamber according to the embodiment of the present invention may be performed in a pressure range (50 to 150 mTorr) where local electron kinetics is applied, in which case the etching rate at the edge may be higher than that at the center.

[0138] Therefore, the plasma chamber for etching a wafer and the method for etching a wafer using the plasma chamber according to the embodiment of the present invention have an advantage in that it is possible to prevent a decrease in uniformity at the edge of the wafer.

[0139] The plasma chamber for wafer etching and the wafer etching method using the plasma chamber according to the embodiment of the present invention are suitable for HARC (High aspect ratio etch) processes, and can obtain high etching rates and high selectivity at low power in other processes as well.

[0140] Although the plasma chamber for wafer etching and the method for wafer etching using the plasma chamber according to the embodiment of the present invention have been described mainly for the etching process, the present invention is not limited thereto. The plasma chamber for wafer etching and the method for wafer etching using the plasma chamber according to the embodiment of the present invention can be applied to processes such as deposition, ashing, PR stripping, doping, etc. in addition to the etching process.

[0141] The plasma chamber for wafer etching and the wafer etching method using the plasma chamber according to the embodiments of the present invention may be applied to etching processes and deposition processes that require an etching rate, but are not limited thereto, and may of course be applied to many processes that simultaneously require a high etching rate and improved selectivity at low power.

[0142] The plasma chamber for wafer etching and the method of etching a wafer using the plasma chamber according to the embodiment of the present invention can be used to improve on inductively coupled plasma (ICP), but is not limited to this and can also be used with various types of plasma.

[0143] Although the present invention has been described with reference to the embodiment shown in the drawings, this is merely illustrative, and a person skilled in the art will understand that various modifications and variations of the embodiment are possible. Therefore, the true technical scope of the present invention should be determined by the technical ideas of the appended claims.

Claims

1. In a plasma chamber for forming a plasma for etching a wafer, a housing having an internal reaction space for etching a wafer via plasma; a base plate provided within the housing on which the wafer is placed; a pressure adjusting portion for adjusting the pressure inside the housing; 2. A plasma chamber for wafer etching, wherein the pressure adjusting unit adjusts the pressure inside the housing to 50 to 150 mTorr.

2. The plasma source is disposed on the upper portion of the housing and configured to generate plasma within the housing.

2. The plasma chamber for wafer etching as claimed in claim 1, wherein the source power of the plasma source is 300 to 1000 W.

3. The plasma source is 3. The plasma chamber for wafer etching as claimed in claim 2, wherein a driving frequency of the plasma source is set to be the same as a collision frequency between particles inside the housing.

4. The density of the plasma formed in the reaction space of the housing is Cubic centimeters (cm －３ 2. The plasma chamber for wafer etching according to claim 1, characterized in that the ion exchange coefficient is 5E10-5E11 per 1000 sq. m.

5. The temperature control unit further includes a temperature control unit for controlling the temperature of the base plate.

2. The plasma chamber for wafer etching as set forth in claim 1, wherein the temperature control unit controls the temperature of the base plate to 20 to 50 degrees (.degree. C.).

6. The base plate further includes a bias RF source connected to the base plate and capable of applying a bias to the base plate; 2. The plasma chamber for wafer etching as claimed in claim 1, wherein the bias power of the bias RF source is 1000-3000W.

7. the plasma formed in the reaction space of the housing includes ions and radicals; 2. The plasma chamber for etching a wafer as set forth in claim 1, wherein the wafer is etched by a synergy effect of the ions and the radicals.

8. the plasma formed in the reaction space of the housing includes electrons; 2. The plasma chamber for wafer etching as set forth in claim 1, wherein an electron energy relaxation length of the electrons is smaller than a diameter of the housing.

9. A wafer etching method for etching a wafer through a plasma chamber including a housing having a reaction space therein for etching the wafer through plasma, a base plate provided within the housing and on which the wafer is placed, a pressure adjusting unit for adjusting a pressure within the housing, and a plasma source provided on an upper portion of the housing for forming plasma within the housing, a pressure adjusting step of adjusting the pressure inside the housing to 50 to 150 mTorr via the pressure adjusting unit; a source power adjusting step of adjusting a source power of the plasma source to 300 to 1000 W via the plasma source.

10. A frequency adjusting step of adjusting a driving frequency of the plasma source is included, In the frequency adjustment step, 10. The method of claim 9, further comprising adjusting a driving frequency of the plasma source so that the driving frequency of the plasma source is equal to a collision frequency between particles inside the housing.

11. The density of the plasma formed in the reaction space of the housing is Cubic centimeters (cm －３ 10. The wafer etching method using a plasma chamber according to claim 9, wherein the concentration of the plasma in the plasma chamber is 5E10 to 5E11 per 1000 s.p.m.

12. the plasma chamber includes a temperature control unit for controlling a temperature of the base plate, 10. The method of claim 9, further comprising: adjusting the temperature of the base plate to 20 to 50 degrees (.degree. C.) via the temperature controller.

13. The plasma chamber includes a bias RF source connected to the base plate and capable of applying a bias to the base plate; 10. The method of claim 9, further comprising: adjusting a bias power of the bias RF source to 1000 to 3000 W via the bias RF source.

14. the plasma formed in the reaction space of the housing includes ions and radicals; 10. The method of claim 9, wherein the wafer is etched by a synergy effect between the ions and the radicals.

15. the plasma formed in the reaction space of the housing includes electrons; 10. The method of claim 9, wherein an electron energy relaxation length of the electrons is smaller than a diameter of the housing.

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