TWI243200B - Chemical/mechanical polishing slurry and chemical mechanical polishing method using the same - Google Patents

Abstract

CMP (chemical/mechanical polishing) slurries that can rapidly remove a target layer and can effectively passivate a polishing stopper, with high selectivity. In one aspect, a CMP slurry comprises metal oxide abrasive particles, a removal rate accelerator, an anionic polymeric passivation agent having a molecular weight in a range of about 1,000 to about 100,000, a C1-C12 anionic passivation agent, and water.

Description

1243200 说明 Guilt and explanation (Invention description should state: technical jaw field, prior technology, content, implementation mode, and drawings of the invention are briefly explained.) Refer to the claim of this application for the submission of the relevant application. 8/1 The priority of Korean Patent Application No. 2002-48403 filed on 6/2 0 0 2 is hereby incorporated by reference. FIELD OF THE INVENTION The present invention relates to a CMP (chemical / mechanical removal) slurry used in the manufacture of microelectronic devices. In particular, the present invention relates to a CMP slurry having a Southern selectivity that can be quickly removed from the target formation and effectively removed the terminating layer. BACKGROUND OF THE INVENTION Semiconductor devices continue to become more integrated and smaller due to multilayer connections, and therefore the number of processing steps needs to be increased in order to form multiple conductive or insulating layers on a wafer. In order to reduce the number of steps in the fabrication of semiconductor devices, C MP (which is a combination of chemical and mechanical processes) is often used. CMP was developed after 1980 by the International Business Machines Corporation. Because of its development, CMP is used as the core micro-processing technology in almost all manufacturing stages of manufacturing 64 Mbit or larger memory and non-memory devices. At present, CMP has further consideration for the application of manufacturing next-generation g a g a b i t level DRAM memory or equivalent non-technical devices. CMP is one type of planarization process. In the CMP, “the irregular surface of the wafer is pressed against the relatively rotating grinding pad” and the polishing paddle is flowed to the contact area between the wafer and the grinding pad. C M P smoothes the surface of irregular crystals through chemical and physical reactions. The performance of C MP is determined by various factors, such as the operation strip of the C MP device 1243200 ⑺ hair date dirty 5¾ '. Among these factors, the type of slurry used by C MP is an important factor affecting the performance of the removal. However, for conventional CMP slurry, it is used to form a shallow trench separation (STI) or an interlayer dielectric (ILD) layer in which an automatic alignment contact hole is formed that exposes the source / drain region of the DRA M. The selectivity ratio of the target layer (for example, the oxide layer) to the stop layer (for example, the silicon nitride layer) is 4: 1, and the selectivity is not good. Therefore, the research termination layer will be over-engineered. In order to avoid excessive removal of the termination layer, it is necessary to increase the thickness of the termination layer. Moreover, for general lapping, the thickness of the lapping stop layer left after CMP will change, resulting in uneven wafer surfaces and reducing the latitude of subsequent device manufacturing processes. Therefore, the characteristics of the semiconductor device are impaired. Therefore, a new and highly selective CMP slurry is needed. SUMMARY OF THE INVENTION The present invention is directed to a method for manufacturing a CMP slurry with high selectivity. The C MP slurry of the present invention has high selectivity, can quickly remove the target layer, and effectively passivate the removal termination layer. The selectivity of the target layer of the CMP slurry of the present invention to the removal of the termination layer is about 30: 1 to about 50: 1. An object of the present invention is to provide a slurry, including metal oxide abrasive particles, removal accelerator, anionic polymer passivating agent with a molecular weight of about 1,000 to about 100, 0 0, and C 1-C. 1 2 Anionic passivator and water. Preferably, the metal oxide abrasive particles include hafnium oxide, silicon oxide, oxygen chain, titanium oxide, oxide and germanium oxide, or any combination of the foregoing materials. Preferably, the removal accelerator includes a phosphonate compound or a phosphonate compound. Preferably, the anionic polymer passivation agent includes poly (acrylic acid), poly (methacrylic acid), poly (acrylic acid-maleic acid), poly (methacrylic acid-maleic 1243200 class 0) acid), poly (acrylic acid- Acrylamide), poly (acrylonitrile-butadiene-acrylic acid), poly (acrylonitrile-butadiene-methacrylic acid) or derivatives or salts of the foregoing materials, or any combination of the foregoing materials. The slurry of the present invention may further include a p Η control agent. The pH of the slurry is preferably between about 3 and about 6. According to another object, the CMP slurry of the present invention is used in a chemical / mechanical removal process. For example, the slurry can be used for chemical / mechanical removal of the deposition termination layer and the target layer to be removed. The target layer to be removed may be an oxide layer, and the stop layer may be a silicon nitride layer. The CMP process includes adding a wafer to a CMP device, and performing CMP on a target layer on the surface of the wafer, and applying 'the C MP slurry of the present invention between the surface of the target layer on the wafer and the pad. These and other objects, objects, features and advantages of the present invention will become apparent from the following detailed description and preferred specific examples, which are read in conjunction with the accompanying drawings. Brief Description of the Drawings Figure 1 is a flow chart illustrating a method for preparing a chemical / mechanical removal (CMP) slurry of the present invention. Fig. 2 is a schematic diagram of a CMP apparatus capable of performing a CMP method using the CMP slurry of the present invention. FIG. 3 is a flowchart illustrating a CMP method which is an object of the present invention. Figure 4 is a graph illustrating the change in removal rate of oxide (PE-TEOS) as a function of the amount of ammonium phosphate. Figures 5, 6 and 7 are illustrations of silicon nitride (3 丨 > 〇 and? £-££) parental removal rate and selectivity as different additives used in the various slurries of the invention. Addition amount 1243200 1_ (4) A graph of the daily discriminant function. Figure 8 is a graph illustrating the change in the removal rate of SiN and PE-TEOS as a function of the pH of the slurry. Figure 9 is a graph illustrating the Γ potential of SiN and PE-TEOS as a function of the pH of the slurry. ', Figures 10, 11 and 12 are cross-sectional views illustrating a method for preparing a sample wafer to be removed using the CMP slurry of the present invention. Figure 13 is a sample after CMP using the slurry of the present invention. A cross-sectional view of the wafer. Figure 14 is a graph of oxide removal rate as a function of CMP slurry selectivity. Figure 15 is a list of reaction diagrams illustrating the method of dissolving an anionic passivating agent to produce an anionic polymer. Detailed description of specific examples The chemical / mechanical milling (CMP) slurry according to the present invention and the CMP method using the slurry will be further described with reference to the drawings. It should be understood that the present invention may include many different forms and is described herein The specific examples should not limit the scope of the present invention in any way. Specific examples are provided to make the disclosure more thorough and complete, and fully cover the concept of the invention understood by those skilled in the art. It is necessary to further understand that in the drawings, the thickness of layers and regions has been simplified and enlarged to make it clearer and used The same reference number refers to the same or similar components. Generally, the highly selective CMP slurry of the present invention preferably includes a mixture of abrasive particles and first, second, and third additives to adjust the characteristics of the slurry. 1243200 Issue: Tomorrow and Sun; <% '" k VSW " 7 ,, \', \ >, / (5)

. In particular, the CMP slurry of the present invention includes metal oxides as abrasive particles. Suitable metal oxides include sieves, stone oxides, oxides, titanium oxides, zirconias, germanium oxides, or similar materials or mixtures of the foregoing materials. Preferably, the metal oxide abrasive particles are mixed with deionized water so that the concentration is about 0.5% to about 25% (wt) based on the total weight of the slurry (hereinafter referred to as wt%). If the amount of the metal oxide abrasive particles is less than 0.5 wt%, the removal rate becomes too low. If the amount of the metal oxide abrasive particles is more than 25 wt%, the stability of the slurry dispersion cannot be determined. For these reasons, the above-mentioned concentration range is a preferable range of the abrasive particles. The first additive is preferably a removal accelerator. Preferably, the removal accelerator includes materials that increase the rate at which the target layer to be removed is removed. Suitable removal accelerators include, for example, salt filling compounds or linoleates. Preferred phosphonium salt compounds include, for example, ammonium bisulfate, dihydroxanthate, diratharyl linoleate, bis (2-ethylhexyl) phosphonate '2-aminoethyl dirrolates, 4 -Airborne diazo hexafluorophosphate, nitrobenzene diazo hexafluorophosphate, six *% ·

Ammonium fluorophosphate, bis (2,4-diphenylphenyl) aerophosphate, bis (2-ethylhexyl) hydrogen phosphate, calcium fluorophosphate, diethyl chlorophosphate, diethyl chlorothiophosphate, six Potassium fluorophosphate, pyrophosphate, tetrabutylammonium hexafluorophosphate, tetraethylammonium hexafluorophosphate, or any combination of the foregoing. Preferred underfilling compounds include, for example, bis (2-ethylhexyl) phosphite. According to a specific example, the additive concentration for removing the accelerator is based on the total weight of the slurry, and is preferably about 0.01 to 10 wt%. If the amount of the accelerator removed is less than 0.001 wt%, the removal rate becomes too low. If the amount of accelerator removal is more than 10 wt%, the stability of the slurry dispersion becomes poor, and -10-1243200 (6) the removal rate cannot be controlled. For these reasons, a preferable range of the above-mentioned concentration accelerator. According to another specific example, the removal acceleration is preferably between about 0.01 wt% and about 1 wt%. For the second kind of additive, it is better to use a research removal layer, which can also improve the dispersion stability of the abrasive particles, and adjust the research. When the stop layer is a silicon nitride layer and the target layer is oxidized, the molecular weight of the anionic polymer passivating agent used as the second additive passivating agent is based on the mobility of the research polymer, which is about 1 0 0,0 compared to 4 0 0. Suitable anionic polymer passivating agents include (such as poly (acrylic acid) and poly (fluorenyl acrylic acid)), copolymers of enoic acid-maleic acid), poly (fluorenyl acrylic acid-maleic acid), and polyoxamine) ), Terpolymer (such as poly (acrylonitrile-butadiene-selective (acrylonitrile-butadiene-fluorenyl acrylic acid)), or one of the foregoing materials, or any combination of the foregoing materials. According to one specific example, The total weight of the anion + polymer passivating agent is based on the total weight, preferably about 0.01 to 1 wt%. If the amount of the compound passivating agent is less than 0.0 0 1 wt%, the passivating agent is polymerized without particles. If the amount of chemical passivation agent exceeds about 10 wt%, the research will be low. According to another specific example, the total weight of the anionic polymer passivation agent is about 0.0 1 wt% to about 1 wt%. Passivation is preferably used As an inactive three additives to improve the removal of the terminating layer. When the terminating agent is a silicon nitride layer, C 1-C 1 2 anion passivation agent. Suitable C 1-C 1 2 anions such as phthalic acid S purpose compounds such as Hydrogen phthalate. Mmm: ί: Dialogue agent in the range of the amount of remover added, compared with 4 when the slurry is a fluid layer. Anionic poly-r is about 10,000 to, for example, a homopolymer (such as poly (propyl (propyl-acrylic acid) -propionic acid), a poly derivative or a salt added to grind the slurry. If the anion polymerizes, if the anion rate Become too large to rank first for slurrying, it is better to use a passivator containing 1243200 _ 杳 杳 Obviously according to one specific example, the amount of C 1-C 1 2 anionic passivating agent is based on the total weight of the slurry It is preferably about 0.01 wt% to about 10 wt%. If the amount of the C 1 -C 1 2 anionic passivator is less than about 0.01 wt%, a high selectivity cannot be ensured. The amount of C 1-C 1 2 anionic deactivator exceeds about 10 wt%, and the removal rate becomes too low. For these reasons, the above-mentioned concentration range is a preferred range for removing the accelerator. According to another specific example The addition amount of the passivating agent (the third additive) is preferably about 0.01 wt% to about 1 wt% based on the total weight of the slurry. The CMP slurry of another specific example of the present invention further includes a pH control agent. Provide the best p 研 of the slurry. The p Η of the slurry varies with the composition of the target layer and the removal termination layer. When the target layer to be removed is an oxide layer, and The removal termination layer is a silicon nitride layer, and the ρ Η of the slurry is preferably adjusted between about 3 and about 6. A suitable pH control agent includes a base such as potassium hydroxide (K0Η), ammonium hydroxide (NH4). H), sodium hydroxide (NaOH), tetramethylammonium hydroxide (TMAH) or biliary test. In addition, suitable ρ Η control agents include, for example, sulphuric acid (Η 2 S〇 4), salt s complex ( hci), phosphoric acid (η3ρ〇4), nitric acid (ην〇4), or acetic acid (CH3COOH). Preferably, in the CMP slurry aqueous solution of the present invention, due to the effects of the first, second, and third additives, the removal rate of the target layer can be increased, and the termination layer can be more effectively passivated. Obtain high selectivity. For example, by using a removal accelerator as the first additive, the removal rate of the target layer (such as an oxide layer) to be removed can be adjusted from about 2,000 to about 6,000 angstroms / minute. between. Secondly, by using an anionic polymer passivating agent (preferably having a molecular weight between about 1,000 and about 100,000) as the second additive, the anionic polymer is dissolved in the aqueous CMP As a passivating agent in the slurry, it also restricts the mobility of the abrasive particles 1243200 3200 particles in the overall phase, affecting the flowability of the slurry.

The anion polymer in the positive phase. When the surface is positively charged, the phase synchronizer in the polyion passivation, the point in the oxide's film pH. The anionic polymer passivating agent dissolved in the aqueous slurry produces a large number of ionic polymers. This is illustrated in the reaction diagrams described in FIG. 15. Anionic compounds are strongly absorbed on positively charged surfaces by electrostatic adsorption. J: Inversely, anionic polymers are repelled by negative charges due to electrostatic repulsion. Therefore, the anionic polymer in the CMP slurry is absorbed on the passive surface. Therefore, the negatively-charged regions of the wafer can be selectively removed, while the positively-charged regions are protected from being removed. · As mentioned above, the anionic polymer soluble in aqueous CMP slurry can be used as a passivating agent, and it can also limit the movement of the abrasive particles in the whole, affecting the flowability of the polymerization. When the surface of the wafer is inexperienced, the large step area of the wafer can be quickly removed, and the small step area can be slowly removed by the anion passivation agent. C 1-C 1 2 anion passivation agent is preferably used as the third additive to improve the purification effect of the above anionic polymer agent. In fact, the C 1 -C 1 2 anionic passivation meter is better soluble and negatively charged in aqueous slurry, for example, C 8 Η 40 4 2-when using potassium hydrophthalate. In order to increase the selectivity of the passivation function, the target layer to be removed should be negatively charged in the aqueous slurry, and the nitrogen removal termination layer in the aqueous slurry should be positively charged. The surface of the water-based slurry card is positively charged when the pH of the slurry is lower than the isoelectric point, and it is negatively charged when the pH of the slurry is greater than the isoelectric point. Therefore, by controlling the ρ 研 of the slurry, two different charges can be made to have opposite polarities. Therefore, according to a specific example of the present invention, it is preferable to adjust the pulverizing agent to an optimal level using a ρρ control agent. In order to increase the processing latitude and reduce the occurrence of dishing, it is better to adjust 1243200 Fansang Lion (9) The CMP slurry of the present invention, so that the selectivity of the target layer to remove the termination layer is about 30: 1 to Between about 50: 1. Hereinafter, a method for preparing a highly selective CMP slurry of a specific example of the present invention will be described with reference to FIG. First, the abrasive particles are placed in a high-shear kneader containing deionized water (step S 10). The deionized water and the abrasive particles are mixed in advance (step S 1 2). In the pre-mixing (step S 1 2), the amount of the abrasive particles is based on the total weight of the final slurry, which is adjusted between about 0.5 wt% and about 0.2 5 wt%, and the p system of the slurry is adjusted to a weak acid. Range and weak test range. Using a pump, move the ground polymer mixture into a suitable dispersing device (such as a media grinder or ultra-high pressure dispersing device), followed by sufficient dispersing under high pressure (step S 1 4). Any dispersion device can be used. However, considering various factors, such as the reproducibility of the dispersion, reducing the pollution during the dispersion process, and the average particle size and dispersibility after dispersion, it is better to use an ultra-high pressure dispersion device. When durability is considered, it is preferable that the ultra-hard dispersion chamber (which is the core part of the ultra-high-pressure dispersion apparatus) is formed of diamond. During the high-pressure dispersion process, an appropriate pressure of about 10, 0 0 0 p s i to about 20, 0 0 0 p s i is added. If the pressure is lower than this range, the dispersion efficiency becomes too low. If the pressure is greater than this range, it will negatively affect the system efficiency and the durability of the chamber. After the average slurry size is controlled by ultra-high pressure dispersion, deionized water can be further added to appropriately control the concentration of abrasive particles in the slurry. Next, add the first, second, and third abrasives to achieve the required slurry properties (step S 1 6). In particular, remove the amount of accelerator (which helps remove the target layer to be removed). From about 0.01 wt% to about 10 wt%. Anion 14 1243200 _ no) 丨 fans The amount of polymer passivating agent and C 1-C 1 2 anionic passivating agent are each about 0.0 1 w t% to about 10 w t%. When the first, second, and third additives are not added to the optimum p Η, then the p Η control agent may be added as appropriate to obtain the optimal p 可视. The amount of addition and / or ρ Η controlling agent added to prepare the CMP slurry of the present invention is preferably determined by the effect of the aqueous CMP slurry, and is optimized for the best removal effect. After the additives are mixed and the pH of the slurry is adjusted, the slurry is passed through a filter to quickly remove relatively large particles (step S 1 8). This filtering step reduces scratches that occur on the surface of the target layer during the study. After the slurry has been filtered, the slurry is analyzed to set its general physical properties and properties. The CMP method of each specific example of the present invention will be described later with reference to Figs. 2 and 3, for example. Referring to Fig. 2, in a CMP apparatus, a grinding plate 20 having a grinding pad 21 is connected to a first rotation shaft 22 rotated by a motor (not shown) and rotated therearound. The grinding head 30 is placed on the grinding pad 21 and attached to a second rotation shaft 32 which is rotated by a motor (not shown). The grinding head is rotated in a direction opposite to that of the grinding plate 20. The wafer 36 (to be subjected to CMP) is detachably fixed to the polishing head 30 by a jig 34 provided on the surface of the polishing head 30. The slurry 42 of the present invention is supplied to one side of the slurry removing plate 20 through the slurry supply line 40. According to the CMP process of the present invention (refer to FIGS. 2 and 3), a wafer to be subjected to CMP and a CMP slurry 4 2 are prepared (step S 50). Next, the wafer 36 is fixed to the research head 30, and the CMP slurry 42 is supplied to the wafer 36 (step S52). 1243200 (ii) The wafer 36 may include the oxide layer of the target layer to be removed and the nitride nitride layer as the stop layer for removal. The highly selective CMP slurry of the present invention can be applied to a wafer that will be formed with shallow trench separation (STI) and interlayer dielectric (LD) films. According to the current s TI and ILD model formation process, oxide layers (such as high-density plasma chemical vapor deposition (HDPCVD) formed high-density plasma oxide layer, or plasma-lifted chemical vapor deposition (PECVD) formed The plasma-lifted tetraethylorthosilicate (PE-TEOS) layer) is the layer to be removed, and the silicon nitride layer (which is deposited by low-pressure chemical vapor with a pressure of several hundred mTorr or lower ( LPCVD) formation, or. PEC VD formation at a high temperature of about 500 ° C to about 600 ° C, which functions like removing a termination layer. When the highly selective slurry of the present invention is supplied to a wafer (step S 5 2) After that, the trench filling layer or the IL D layer is removed (step S 5 4). The present invention will be described in more detail with reference to the following experimental examples. Technical information that is familiar to the skilled person and can be easily inferred is not fully described in In the following experimental examples, the following experimental examples are intended to illustrate the use of 'not intended to limit the scope of the present invention. Experimental Example 1 In this experiment', the method described in FIG. 1 shall prevail. Accelerator ammonium hydrogen phosphate (A Η P) added to 1 wt% of the first additive Prepared in an aqueous solution of thallium (metal oxide abrasive particles). PE-butyl EOS blank wafers (each oxide (PE-TEOS) layer with a thickness of 8000 angstroms) are prepared as sample wafers. Then execute it on the sample wafer, and at the same time will contain different amounts of A Η p (see Table 1 1243200

(Shown in) on top of it 'and the oxide removal rate was measured. c MP is performed using Μ IRRA-Μ ES Α device (RODEL.CO., L td) under the following conditions: IC 1000 stacking pad, film force is 3.5 psi, the ring force is maintained It is 4.5 psi, the inner tube force is 3.5 psi, the turntable speed is HO rpm, the head speed is 104 rpm, and the slurry flow rate is 300 ml / min. C MP results are listed in Table 1. Figure 4 is a graphical representation of the results. Table 1 AHP, wt% oxide (PE-TEOS) removal rate, Angstroms / minute pH 〇1655 5 0.05 4602 5 0.1 14499 5 0.5 2875 5 As can be clearly seen from Table 1 and Figure 4, compared to the absence of A Y P, when A Y P is added, it will increase the oxide removal rate. However, when the amount of additive force σ of A Y P is further increased or the oxide removal rate is decreased. This result is believed to be caused by the excess phosphate group dissolving in the slurry and being adsorbed on the abrasive particles to hinder C MP, which can be inferred from the fact that the abrasive particles are precipitated when an excessive amount of A PP is added. Taking into account the appropriate oxide removal rate and the prevention of the precipitation of abrasive particles, the preferred addition amount of AΗP is determined to be about 10 wt% or less, and preferably about 1 wt%. Test Example 2 In this experiment, Various slurries were prepared by adding 0.2 wt% AAP and different amounts of poly (fluorenyl acrylic acid) (PMA) as anionic polymer passivating agents in an aqueous solution containing 1 wt% hafnium oxide. Preparation of PE-TEOS and silicon nitride (Si3N4) control wafers as sample wafers, in which the thickness of the oxide (PE-TE0S) layer and the silicon nitride layer were 1243200 ι_ι (13) | : Thin page 8,000 Egypt 2,000 Angstroms. C MP was performed on the sample wafer, while using the same C MP device as in Experimental Example 1 and under the same operating conditions, a slurry prepared with the composition of Table 2 was supplied. Oxide and silicon nitride removal rates were measured during the CMP process. The results are listed in Table 2 below. Figure 5 is a graphical illustration of the results. Table 2 AHP, wt% PM A, wt% pH removal rate, Angstroms / minute-selective oxide (PE-TEOS) silicon nitride (Si3N4) 0.25 0.05 5 3993 1078 3.7: 1 0.25 0.1 5 3706 975 3.8: 1 0.25 0.5 5 2448 679 3.6: 1 0.25 1 5 1617 478 3.4: 1

It is clear from Table 2 and FIG. 5 that as the amount of PMA as an anionic polymer purification agent increases, the silicon nitride removal rate decreases. Prove the effect of anionic polymer deactivator. However, as mentioned above, increasing the amount of anionic polymer passivating agent causes the oxide removal rate to decrease linearly. For all sample wafers using only PMA as a passivator, the selectivity is relatively low. Experimental Example 3 In this experiment, 0.2 wt% AΗP and different amounts of hydrogen phthalate (P Η P) were added as Cb C 1 2 anionic passivating agent to a 1 wt% hafnium oxide aqueous solution to prepare various slurries. . The same sample wafer as in Experimental Example 2 was prepared, and the same MP device and the same operating conditions as those in Experimental Example 2 were used to perform C MP. The oxide and nitride removal rate and selectivity were measured during the C MP process. . The results are listed in Table 3 below. Figure 6 is a graphical illustration of the results. -18- 1243200 Difficult: Funeral: Still, > ϊ-t V · ν ν > «· V ν > (14)

AHP, wt% PHP, wt% pH Quick removal, Angstrom / minute selective oxide (PE-TEOS) Silicon nitride (Si3N4) 〇 0 5 1242 542 2.3: 1 0.2 〇5 2668 1206 1 2.2: 1 0.2 0.01 5 2615 1155 2.3: 1 0.2 0.1 5 2668 899 3.0: 1 0.2 0.25 5 2744 772 3.6: 1 It is clear from Table 3 and Figure 6 that the amount of P Η P used as C 1-C 1 2 anionic passivating agent Increasing it will decrease the silicon nitride removal rate. Demonstrate the passivation of anionic passivation agents. Moreover, compared to the case of increasing the anionic deactivator, increasing the amount of the anionic deactivator slightly increases the removal rate of the oxide. As in Experimental Example 2 (in which only one type of passivation agent (PMA) is used), when only PΗP is added as a passivation agent, the selectivity in all test samples is relatively low. Experimental Example 4 In this experiment, based on the results of Experimental Examples 1, 2 and 3, it was prepared by adding 0.0 5 wt% of AΗP, PM A and PΗP in an aqueous solution containing 1 wt% scandium oxide. Various mortars. The amount of PMA was fixed at 0.05 wt%, and the amount of PHP was changed to prepare different mortars. The same sample wafer as in Experimental Example 2 was prepared, and the same CMP apparatus as in Experimental Example 2 was used and CMP was performed under the same operating conditions. During CMP, oxide and silicon nitride removal rates and selectivity were measured. The results are listed in Table 4 below. Figure 7 is a graphical illustration of the results. -19-1243200 (15) Table 4 ΑΗΡ, wt% PMA, wt% PHP, wt% pH removal rate, Angstroms / minute Selective Oxide (PE-TEOS) Silicon Nitride (Si3N4) 0.05 0.05 0.01 5 4641 82 57: 1 0.05 0.05 0.05 5 4890 75 65: 1 0.05 0.05 0.1 5 4960 62 80: 1 0.05 0.05 0.5 5902902 95: 1 It can be clearly found from Table 4 and Figure 7 that when the second type of anionic passivating agent (P M A And P Η P) when used together, high oxide selectivity to silicon nitride will be obtained. Experimental Example 5 In this experimental example, by adding 0.0 5 wt% AΗP, 0.0 5 wt% P M A, and 0.0 5 wt% PΡ P in an aqueous solution containing 1 wt% oxidation sieve, followed by 1 M- H2S04 solution and potassium hydroxide standard solution were used to adjust the pH to prepare various mortars with different pH levels. The same sample wafer was prepared as in Experimental Example 2, and the same CMP apparatus was used as in Experimental Example 2 and CMP was performed under the same operating conditions. Measure oxide and silicon nitride removal rates during CMP. The results are listed in Table 5 below. Figure 8 is a graphical illustration of the results. Table 5 pH removal rate, Angstroms / minute Selective Oxide (PE-TE0S) Silicon Nitride (Si3N4) 4 3544 40 89: 1 4.5 3904 44 89: 1 5 4214 61 69: 1 5.5 4458 82 54: 1 6 5190 129 40: 1 7 4750 1197 4: 1 -20-1243200 One by one ... (16) Xi Minglinan: Suspect, it can be clearly found from Table 5 and Figure 8 that when the ρ 研 of the mortar increases, the oxide The removal rate of (PE-TEOS) and silicon nitride will increase, and when the pH reaches and exceeds about 6, the removal rate of silicon nitride will increase significantly. In addition, when ρ Η is about 6 or higher, the selectivity may suddenly decrease. Obviously, CMP with ρ 6 of 6 or less is effective for increasing the selectivity of oxides to nitrides. The decrease in selectivity at higher ρ 系 is due to less passivation agent on the thinly-loaded silicon dioxide layer. Basically, this is due to the degree of decomposition of the passivation agent and the surface charge of the silicon nitride layer as ρ ρ changes. Regarding the degree of decomposition, the decomposition constants of the functional groups-COOH and PMA of PP are about 4.2, so they can be completely decomposed at a pH of 5 or lower. However, when the pH value is neutralized basic ρ Η, the degree of decomposition decreases. Therefore, less negative charges contained in the passivation are generated by the passivation agent, which reduces the selectivity. From the viewpoint of silicon nitride surface charge, the decrease in selectivity can be explained as follows. The intrinsic surface charge of a layer can be expressed in r (Q potential, mV). The solution ρ 时 when the sign of the C potential in the layer changes is called the isoelectric point. As shown in FIG. 9, the isoelectric point of the HDPC VD or PEC VD oxide layer is about pH 3, and the LPCVD or high-temperature PECVD silicon nitride layer is about pH 6. When the pH of the slurry is lower than the isoelectric point of the layer, the surface of the layer is positively charged in the slurry. When the pH of the slurry is greater than the isoelectric point of the layer, the surface of the layer is negatively charged in the slurry. Therefore, when the pH in the slurry is about 3 to 6, the surface of the silicon nitride layer is positively charged and the surface of the oxide layer is negatively charged. Therefore, when the anionic polymer passivating agent and the C 1-C 2 0 anionic passivating agent are decomposed and negatively charged, the passivating agent will load the surface of the silicon nitride layer and passivate it effectively. 1243200 / Ί, Miscellaneous Zen (1 /) j <, 2 ,, Experimental Example 6 In this experiment, by adding 0 0 5 wt% A Η P, 0, 0 5 wt% P Η P and anionic polymer The purifying agent was used to prepare various slurries in an aqueous solution containing 1 wt% oxidized brocade. Different anionic polymer deactivators with different molecular weights are used to prepare different slurries. The same sample wafer 'as in Experimental Example 2 was prepared, and using the same CMP device as in Experimental Example 2 and performing c M p under the same operating conditions. The C M P process measures oxide and silicon nitride removal rates and selectivity. The results are shown in Table 6. Additive removal rate, Angstroms / minute Selective Oxide (PE-TEOS) Nitriding (Si3N4) ΑΗΡ + ΡΗΡ Ten PAA (Mw: 1, 200) 5567 140 40: 1 AHP + PHP + PAA (Mw; 5,000) 6414 139 46: 1 AHP-fPHP + PAA (Mw; 8,000) 5179 123 42: 1 AHP + PHP + PAA-co'MA (Mw; 3'000). 4241 94 45 : 1 AHP + PHP + PAA-co-MA (Mw; 50,000) 3982 117 34: 1 In Table 6, MPAΑΠ is shorthand for poly (acrylic acid) '' 'PAA-co-MA "is poly (acrylic acid-maleic acid) ), And M w ”is a molecular weight. It is clear from Table 6 that as the molecular weight of the anionic polymer passivator increases, the selectivity of the 'oxide to silicon nitride decreases. A better selectivity range for processing latitude is from about 30: 1 to about 50 ·· 1. Therefore, it is preferred to use an anionic polymer passivating agent having a molecular weight of about 1,000 to about 1,000. f Examination Example 7 In this experiment, the sample wafers (each including all 39 wafers) were prepared by the ST I process of 0.1 μm DRMA. Referring to FIG. 10 ′ system via oxide layer 1 0 2 1243200

The sun and the moon explained that the flooded page 1 and the silicon nitride layer 104 were sequentially deposited on the wafer. The silicon nitride layer 104 is LPCVD at a pressure of several hundred mToΓΓ or lower, or PECVD at a high temperature range of about 500 to about 600 ° C, using digas silane and ammonia (N Η 3) As a reactant gas, it was deposited to a thickness of 5 50 angstroms. After the photoresist pattern 106 is formed to define the trench area, the photoresist pattern 106 is used as an etch protection etch to form a silicon nitride layer pattern 104 as a hard protection and removal stop layer. Subsequently, as shown in FIG. 11, the photoresist pattern 106 is removed, and the oxide layer 10 and the wafer 100 are etched using the nitride stone layer pattern 104 as an etch protection part, so that Many shallow trenches 1 0 7. Next, as shown in FIG. 12, an oxide layer 108 is deposited to a thickness of 5500 angstroms to fill the trench 107 and cover the surface of the silicon nitride layer pattern 104. Here, the silicon oxide layer 108 is a PE-TEOS layer formed using PECVD. The highly selective slurry of the present invention is prepared by adding 0.05 wt% AHP, 0.05 wt% PM, and 0.05 wt% PΗP in an aqueous solution containing 1 wt% ytterbium oxide, and then prepared by adjusting the pH to 5. . 4'Yanken Polymer was used to advance 1 '亍 C ΪM P' on the sample wafer and the silicon nitride layer pattern 104 on the sample wafer was used as the removal stop layer. A 6ED device (Strasbaugh Co. Ltd.) was used, and CMP was performed using an IC1000 pad and a Suba4 secondary pad. The resulting final structure is described in Figure I3. With respect to the obtained structure, the remaining thickness of the silicon nitride layer pattern I 0 4 as the removal stop layer was measured. Calculate the average of the remaining thickness and its deviation, and measure the depth of dishing in an area of 100 micrometers by 100 micrometers. The results are listed in Table 7 below. 1243200

Sample wafer number CMP conditions (lower platen speed) Deviation of the thickness of the remaining nitride layer pattern, the average thickness of the remaining nitride layer pattern, _Eb, 7 depth, Angstrom 1 3 psi-93 rpm 53 512 233 2 3.3 psi-93 ipm 55 502 278 3 1 3.5 psi-103 rpm 59 510 1 261 4 3.5 psi — 110 rpm 54 505 250 It is clear from Table 7 that when the slurry of the present invention is added, the nitrides removed are removed. The termination layer is 30-50 angstroms. Moreover, the thickness deviation of the remaining nitride layer is as low as 50 to 60 angstroms. Obviously, the slurry of the present invention can provide high oxide-to-nitride selectivity. It can be clearly found from Table 7 that, according to the condition of CMP, the slurry of the present invention can significantly reduce the dishing phenomenon. Experimental Example 8 In this experiment, a slurry having different oxide-to-nitride selectivity was used to measure the oxide (PE-TEOS) removal rate. The sample wafer manufacturing and CMP were performed as in Experimental Example 7, and the oxide (PE-TEOS) removal rate was measured. The results are shown in Table 8 and FIG. 14.

A Selective oxide removal rate, Angstroms / minute 12: 1 3030 19: 1 3237 20: 1 3327 26: 1 2784 33: 1 1200 36: 1 1233 40: 1 1080 45: 1 1347 50: 1 1396 79: 1 1880 104: 1 1822 108: 1 1911 24 1243200 (20) It can be clearly found from Table 8 and Figure 14 that when the slurry is selected] to about 50: 1, the oxide removal rate is about 1.0. 0 to about 0 minutes. Considering the low removal rate of nitride (both the figure and the oxide removal rate), the preferred oxide shift is between P 1, 0 to about 1,500 angstroms / minute. Therefore, it is better Use: 1 to about 50: 1 of the slurry of the present invention to reduce dishing | As mentioned above, when the highly selective slurry of the present invention is used, the thickness variation of the layer is extremely small, and the surface of the wafer is uniform and without evidence. Therefore, the latitude of subsequent processes can be increased. In addition, compared with the CMP slurry, the removal termination layer and the layer to be removed can be reduced. Although the present invention is also referred to its specific examples, it is familiar to those skilled in the art It should be understood that the types and details can be carried out, but they do not deviate from the original hairpin defined by the scope of the patent application for the subsidiary application. The representation of the symbols on the diagram indicates the result of l in about 30: 1 1, 50 angstroms / min. 7) The rate is about 30 L at a selectivity of about. To study the termination of discontinuation. For use with traditional starting thickness. Various changes in display and narrative Ming spirit and norms 20 Research and removal of boards 2 1 Research and removal of pads 22 Rotary shafts 32 Turns of cars by 30 research and removal of heads 34 Clamps 3 6 Crystal circles 40 Research slurry Supply lines 42 Research slurry

1243200 (21) 100 crystal circle 102 pad oxide layer 104 silicon nitride layer 106 photoresist pattern 108 oxide layer

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Claims (1)

J243200 i amended and replaced this I m.] 〇. I | 〇9ig ^ 〇22 patent application 1 year I file application scope replacement (October 1993) Pick up and apply for the scope of specialty 1. A type used in chemistry / Mechanical grinding of wafer slurry, the slurry includes: metal oxide abrasive particles; removal accelerator; anionic polymer passivating agent with a molecular weight of 10,000 to 100,000, wherein the anionic polymer passivating agent Including poly (acrylic acid), poly (methacrylic acid), poly (acrylic acid-maleic acid), poly (methacrylic acid-maleic acid), poly (acrylic acid-acrylamide), poly (acrylonitrile-butadiene) -Acrylic acid), poly (acrylonitrile-butadiene-methacrylic acid) or derivatives or salts of the foregoing materials, and any of their combinations; C 1-C 1 2 anionic passivating agents; and water. 2. For example, the slurry in the scope of patent application, wherein the metal oxide abrasive particles include hafnium oxide, silicon oxide, aluminum oxide, titanium oxide, zirconia, germanium oxide and any combination thereof. 3. For example, the slurry of the scope of patent application, the amount of abrasive particles of metal oxide is based on the total weight of the slurry, 0.5 wt% to 25 wt%. 4. For the slurry of the first scope of the patent application, the removal accelerator includes one of a salt-filling compound and a salt-filling compound. 5: According to the pulp of item 4 of the patent application scope, the phosphate compounds include ammonium hydrogen phosphate, ammonium dihydrogen phosphate, potassium dihydrogen phosphate, bis (2-ethylhexyl) phosphate, and 2-aminoethyl Dihydrogen phosphate, 4-chlorobenzenediazohexafluorophosphate, nitrobenzenediazohexafluorophosphate, ammonium hexafluorophosphate, bis (2,4-dichlorophenyl) chlorophosphate, bis ( 2-Ethylhexyl) hydrogen phosphate, patent application page illillillliie 1243200 calcium fluorophosphate 1 diethyl chlorophosphate, diethyl chlorothiophosphate, potassium hexafluorophosphate, pyrophosphate, tetrabutyl hexafluorophosphate Ammonium, tetraethyl phosphate, or any combination of the foregoing. 6. The slurry according to item 4 of the patent application, wherein the phosphite compound includes bis (2-ethylhexyl) phosphite. 7. As for the pulp of item 1 in the scope of patent application, the amount of accelerator removed is based on the total weight of the pulp from 0.01% to 10%. 8. As for the slurry in the scope of application for item 1, the amount of accelerator removed is 0.01% to 1% based on the total weight of the slurry. 9. For example, the slurry of the scope of application for patent 1, the amount of anionic polymer passivating agent is based on the total weight of the slurry of 0.01 to 10%. 10. For example, the slurry of the scope of patent application, the amount of anionic polymer passivating agent is based on the total weight of the slurry, which ranges from 0.1% to 1%. 11. The slurry as claimed in item 1 of the patent application, wherein the C 1-C 1 2 anionic passivating agent includes phthalate. 12. As for the pulp of item 11 in the scope of patent application, the phthalic acid salt includes potassium hydrogen phthalate. 13. As for the slurry of the first scope of the patent application, the amount of C 1-C 1 2 anionic passivating agent is based on the total weight of the slurry. 0.01% to 10%. 14. As for the pulp of item 1 in the scope of patent application, the amount of C 1-C 1 2 anionic passivating agent is based on the total weight of the pulp from 0.1 to 1%. 15. For the pulp of item 1 of the patent application scope, the pH control agent is still included. 16. If the slurry of the 15th scope of the patent application, the pH control agent includes one of the following: Patent application scope page 1243200 Alkali includes potassium hydroxide, ammonium hydroxide, sodium hydroxide, tetramethylammonium hydroxide Or choline; and acids include sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid, or acetic acid. 17. For example, the slurry of the scope of patent application No. 1 in which the pH of the slurry is 3 to 6 〇18.-A CMP (chemical / mechanical removal) method using the scope of the patent scope of the patented scope 1 in which The wafer includes a target layer to be researched and a research termination layer, wherein the target layer includes an oxide layer, and the research termination layer includes a silicon nitride layer. 19. A CMP (chemical / mechanical removal) method using a slurry such as the one in the patent application scope, wherein the wafer includes a target layer to be removed and a removal stop layer, wherein the target layer includes an oxide layer The removal layer includes a silicon nitride layer, and the oxide layer thereof includes an HDPCVD or PECVD oxide layer, and the silicon nitride layer includes an LDC VD or a high-temperature PECVD nitride layer. 20. If the CMP method of item 18 or 19 is applied for, the selectivity of the target layer and the removal termination layer provided by the slurry is 30: 1 to 50: 1. 21. A CMP (chemical / mechanical removal) method, comprising the steps of: placing a wafer on a chemical / mechanical removal device, the wafer including a removal termination layer deposited thereon and a removal to be removed The target layer; CMP is performed on the target layer on the wafer, and the CMP slurry is added between the surface of the target layer and the pad; the CMP slurry includes metal oxide abrasive particles, accelerator removal, and molecular weight. Anionic polymer passivating agent from 1000 to 10,000, 1243200 C1-C12 anionic passivating agent and water, wherein the anionic polymer passivating agent includes poly (acrylic acid), poly (methacrylic acid), poly (acrylic acid) -Maleic acid), poly (methacrylic acid-maleic acid), poly (acrylic acid-acrylamide), poly (acrylonitrile-butadiene-acrylic acid), poly (acrylonitrile-butadiene-methacrylic acid) ) Or a derivative or salt of the foregoing, and any combination thereof. 22. The method of claim 21, wherein the metal oxide abrasive particles include hafnium oxide, dream oxide, oxidized iS, titanium oxide, oxide and germanium oxide, and any combination thereof. 23. The method of claim 21 in the scope of patent application, wherein the amount of the metal oxide abrasive particles is based on the total weight of the slurry, 0.5% to 25%. 24. The method of claim 21, wherein the removal accelerator includes one of a phosphate compound and a phosphite compound. 25. The method of claim 24, wherein the phosphate compound includes ammonium hydrogen phosphate, ammonium dihydrogen phosphate, potassium dihydrogen phosphate, bis (2-ethylhexyl) phosphate, and 2-aminoethyldi Hydrogen phosphate, 4-chlorobenzene diazo hexakis (6,6) -carboxylate, benzodiazo hexafluorofiller, ammonium hexafluoroscale, bis (2,4-dichlorophenyl) chlorophosphate Bis (2-ethylhexyl) hydrogen phosphate, calcium fluorophosphate, diethyl chlorophosphate, diethyl chlorothiophosphate, potassium hexafluorophosphate, pyrophosphate, tetrabutylammonium hexafluorophosphate, hexafluoro Tetraethyl phosphate, or any combination of the foregoing. 26. The method of claim 24, wherein the phosphite compound includes bis (2-ethylhexyl) phosphite. 27. The method of claim 21, wherein the amount of the accelerator is removed 1243200 is based on the total weight of the grind pulp, 0.01 to 1%. 28. The method according to item 21 of the scope of patent application, wherein the amount of the accelerator removed is based on the total weight of the grind pulp, 0 _ 0 1% to 1%. 29. The method according to item 21 of the scope of patent application, wherein the amount of the anionic polymer passivating agent is based on the total weight of the slurry, from 0.01% to 10%. 30. The method of claim 21 in the scope of patent application, wherein the amount of the anionic polymer passivating agent is based on the total weight of the slurry. 0.001% to 1%. 31. The method of claim 21, wherein the C1-C12 anionic passivating agent includes a phthalate salt. 32. The method of claim 31, wherein the phthalate salt includes potassium hydrogen phthalate. 33. The method according to item 21 of the scope of patent application, wherein the amount of C 1 -C 12 anionic passivating agent is based on the total weight of the slurry. 0.001% to 10%. 34. The method according to item 21 of the patent application range, wherein the amount of the C 1 -C 12 anionic passivating agent is based on the total weight of the slurry. 0% to 1%. 35. The method according to item 21 of the patent application scope further includes a pH control agent. 36. The method as claimed in claim 35, wherein the pH control agent includes one of the following: the base includes potassium hydroxide, ammonium hydroxide, sodium hydroxide, tetramethylammonium hydroxide or bile test; and acid Including sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid or acetic acid. 37. If the method of the scope of patent application No. 21, wherein the pH of the slurry is 3 to 38. If the method of the scope of patent application No. 21, where the target layer to be researched: the application of the difficult baby; 1243200 including filling crystal An insulating layer of a trench in a circle or an interlayer dielectric layer formed on a wafer having an underlying structure. 39. The method according to item 21 of the patent application, wherein the target layer to be removed includes an oxide layer, and the removal stop layer includes a nitrided layer. 40. The method of claim 39, wherein the oxide layer includes an HDPCVD or PECVD oxide layer, and the silicon nitride layer includes an LDCVD or a high-temperature PECVD silicon nitride layer. 41. The method of claim 21 in the scope of patent application, wherein the slurry provides the selectivity of the target layer to the removal of the termination layer 30: 1 to 50: 1.