201215670 六、發明說明： 【發明所屬之技術領域】 本發明係關於一種長期穩定之水性或半水性漿料懸浮 液。更特定而言，本發明提供—種具有長期穩定性特徵 (即稱為軟沉澱特性）之水性及半水性漿料，其可用於包括 研磨應用、線鋸切割、CMP(化學機械拋光/平面化）金屬製 造及拋光、及無磨料研磨之多種商業應用中。 【先前技術】 先前已將非膠體之高密度研磨顆粒之非水性、半水性及 ^生懸浮㈣於晶K之線㈣割及研磨中，但無法獲得穩 定漿料。頒予Stricot之美國專利第5,〇99,82〇號揭示一種含 於水或油中之碳化矽顆粒懸浮液之研磨漿料。然而，該等 懸浮液不穩定且不能藉由線提供均勻之潤滑及切割。該等 組合物要求劇烈攪拌以保持顆粒之均勻懸浮液，且即使在 仍處於攪拌下之工件切割期間，該等懸浮液在靜置條件下 仍迅速沉澱。 2000年10月08日申請iWard等人之共同待審之專利申請 案第〇9/637’263號（現為專利第6,6〇2,834號，其以引用之方 式併入本文令）揭示與線鋸一起使用之非水性或半水性切 割及潤滑組合物’其依靠界面活性劑、聚合電解質及阳提 供靜電排斥及顆粒間干擾，以保持研磨顆粒之穩定懸浮 液。 頒予Ward等人之美國專利第M54,422號揭示—㈣滑組 合物’其纟利用南及低分+重量之聚烧二醇與懸浮劑之混 15124S,oe , § 201215670 合物之懸浮液中含有高達70重量百分比之磨砂物質。 在用於夕種工業（即微電子裝置、太陽能電池、 L.E.D'S、寬帶寬裝置、光學器件/雷射器、晶圓拋光、CMP 應用、其他多種應用）中之矽、Sic、藍寶石、GaAs、光學 玻璃及其他晶圓之製造中，自較大之鑄錠、磚形料、梨 晶等切割晶圓。該晶圓、圓盤、工件等之最初切割後之下 一步驟包括該切割晶圓之研磨，以使表面光滑、降低 TTV、消除損害性深度缺陷及製備用於最終「拋光」之晶 圓。一般而言，使用水性載體作為用於該步驟之研磨劑之 懸洋介質。研磨劑可包括（但不限於）：Sic、氧化鋁、 Zr〇2、矽石、金剛石等。研磨漿料使用尺寸範圍為約0.5 至20 μπι之研磨顆粒。此意指該等懸浮研磨顆粒在尺寸及 性質上通常為非膠體。此並不排除使用膠體研磨劑（即尺 寸範圍為約o.oomo μηι之研磨顆粒），心玄等顆粒通常 並不用於研磨漿料中。 在該晶圓研磨製程期間，用於晶圓、褒置、陶究等之研 磨毁料係經受許多剪切、磨光、及研磨力。在「行星研 磨」製程期間，將該漿料注射至固定於兩個大鐵片之間之 晶圓表面上。固定該晶圓之上部及下部片之逆方向旋轉壓 縮,玄上部片及該晶圓表面之間之装料。該壓縮聚料内之固 體接觸該晶圓，且角動量引起該磨料活動以移除表面晶圓 缺陷並「钱刻」掉所需量之晶圓表面物質。利用如今用於 研磨之所有水性漿料’該㈣上之活動及研磨設備之設計 促使顆粒聚結在該晶圓上、貯存器内、供料管道内、研磨 151248.doc 201215670 器"片上等。該顆粒聚結另外具有在該研磨晶圓上形 成損害性「到擦」之有害影響。隨後必須廢棄該等高成本 晶圓。 非膠體（即NCOL)性高密度研磨顆粒之水性懸浮液已成 為「晶圓」製造廠之嚴重及棘手問題達數十年。至今為 止，不存在將保持「NCOL」研磨顆粒懸浮液達比幾:數 分鐘之極短時間更久之低黏度水性载體。其後，顆粒開始 凝聚並自懸浮液快速沉殺至容器之底部。即使在持續混: 或再循環期間，該研磨顆粒在現有「水性」聚料中仍= 沉澱。此顆粒沉澱通常係顯示為容器底部之「硬沉澱 塊」。任何使可保持原始磨料之最初粒度分佈之漿料=2 之嘗試皆無法藉由簡單混合、㈣、搖晃或類似方法完 成。因此，該等漿料被迅速廢棄，其浪費昂貴之磨料 間、人力、及努力。 · 在先前技術懸浮液中，溫度及阳影響懸浮液在長期靜置 儲存中保持均質及均勾之時間。無機顆粒可保持懸浮於水 性及非水性溶财（其取決於該顆粒之尺寸、晶格結構及密 度），但在靜置儲存中傾向於凝聚並自懸浮液中沉殿 【發明内容】 本發明剌於—種含於水性或半水性載體中之I機或陶 免顆粒之懸浮液，其係保持在周圍溫度及高溫下，並在包 含約7至8.5之pH之寬廣pH範圍内。根據本發明，利用如溶 膠、凝膠、膠狀物、沉澱物等之顆粒使研磨顆粒由於水性 或半水性載體環境中之顆粒間干擾（據信其亦在該環境中 151248.doc s 201215670 產生穩定排斥性ζ電位）而懸浮。該漿料組合物可含有約〇 l 至70重量％之無機或陶瓷研磨物質及約〇〗至2〇重量％之通 常形成之懸浮顆粒，其係由在约4至12之pH範圍内，於水 中形成懸浮賴物之其他金屬氧化物、氫氧化物、及氧化 物水合物組成。該載體之水性内容物可含有約5至丨00重量 %之水，且呈惰性且不與該水介質及包括研磨物質之懸浮 顆粒反應之有機溶劑補足剩餘部份。該等懸浮顆粒之密度 係近似於或小於該載體溶劑組合物。 本發明之總體目標係提供可用於自鑄旋切割薄片之線鋸 應用、研磨應用、CMP應用及類似應用之長期穩定性研磨 漿料懸浮液。 本發明之另一目標係提供一種含於低毒性载體令之研磨 顆粒之長期穩定懸浮液。 本發明之又一目標係提供一種含於中性或接近中性 介質中之膠體或NCOL磨料或其他顆粒之穩定懸浮液。 本發明之另-目標係、提供一種使膠體或NC0L磨料或其 他顆粒在液體中懸浮之非黏度依賴性方法。 【實施方式】 本發明提供一種提供具有長靜置保存期之無聚結或研磨 顆粒硬沉激之含於水性或半水性介質中之顆粒之穩定縣浮 液之方法。根據本發明之-特徵，其提供潤滑載體及研磨 衆料組合物（其在用於線鑛應用（例如將鑄錠或梨晶切割成 用於半導體或光電設備中之晶圓或圓盤）之載體中保持稃 定㉘位環境)' 研磨或拋光装料、⑽研磨毁料及類似 151248.doc 201215670 物，其中顆粒懸浮液係保持在環境溫度及高溫下。藉由提 供約(U至20$量％之懸浮顆教（其提供抗聚結物或硬沉激 物之顆㈣預且具㈣於或近缺該㈣㈣之顆粒密 度）’將該等研磨顆粒保持為水性或半水性漿料。該等懸 浮顆粒係在pH為約4至12下，於水中形成懸浮顆粒沉殿物 (即溶膠、凝膠塊、膠狀沉澱物等)之金屬氧化物、氫氧化 物及氧化物水合物。該等研磨顆粒包括用於線錯切割、金 屬拋光應用之粒度為約3至100 μηι&用於晶圓研磨應用之 通常在約0.5至20 μιη之較低範圍内及用於CMp應用之通常 在約50至1〇00 nm2更低範圍内之習知研磨顆粒。較佳之 懸序顆粒係彼等在房]立形成者（例如#金屬鹽形成金屬氧 化物時）。在此情況下，與市售形式之原位沉澱形式相 比，該等原位製備之沉澱顆粒之密度通常更低且該顆粒之 表面積係更大。另外，原位形成之懸浮顆粒通常具有更寬 之粒度分佈。 用於上述組合物中之研磨物質可包含金剛石、矽石 '碳 化鎢、碳化矽、碳化硼、氮化矽、氧化鈽、氧化錘、氧化 鋁之粉末；或其他硬砂粒「粉末」物質。最常用的研磨物 質之一係碳化矽》—般而言，在線鋸切割應用中，平均粒 度係在約0.5至30微米之範圍内’且較佳為3至20微米，其 係視砂粒粉末之國際「FEPA或JIS」等級稱號而定。該研 磨物質在線鋸切割應用之懸浮液介質或載體中之濃度通常 可在約0.1至60重量百分比磨料之範圍内，且粒度係在約 0.2至50 μηι且較佳約1至3〇 μιη之範圍内。就金屬拋光或研 151248.doc η 201215670 磨應用而言，磨料尺寸係在約6至200 0111且較佳約1〇至1〇〇 μιη之範圍内。就晶圓CMP(即化學機械拋光/平面化）而 言，磨料粒度通常可在約10至2〇〇〇 nm(奈米）且較佳約5〇 至800 nm(奈米）之範圍内。就陶瓷研磨應用而言磨料粒 度通常可在約2至70μιη且較佳約6至50μm之範圍内。 可與水一起使用之溶劑係極性溶劑，其包含醇、醯胺、 醋、驗、嗣、二醇、二㈣、院内、或亞硬1定而 言，極性溶劑之實例係二甲亞砜、二甲基乙醯胺 (DMAC)、N-曱基吡咯啶酮（ΝΜρ)、（γ)丁内酯、二乙二醇 早乙醚、二丙二醇單曱醚、三丙二醇單甲醚 '各種聚乙二 醇及聚丙二醇及類似物。 在某些情況下使用該等有機溶劑，以為所得之漿料提供 必需的黏度水平。有機溶劑之其他用途可包括降低該浆料/ 載體之凝固點。該溶劑之選擇係相對不重要，只要該溶劑 係惰性、不與水或懸浮研磨顆粒反應且具有低毒性及低氣 味即可。 可使用之懸浮顆粒包括（但不限於）形成水性或半水性懸 洋液（即凝膠、膠狀沉澱物、溶膠、膠體或非膠體懸浮 液、固體乳液等）之金屬氫氧化物、氧化物水合物及料 磨顆粒氧化物。此等懸浮顆粒作為本發明之重要組分將不 隨時間沉澱。其包括（但不限於）彼等在介質内或介質外原 位轉變成氫氧化物形式之化合物’例如，如以下實例反應 ，所述之利用金屬或非金屬Br()nstead驗（例如氫氧化卸' 氫氧化四甲基敍、氫氧化鈉、氫氡化四乙基敍、氫氧化鎖 15 ] 248.doc 201215670 等）轉變成氫氧化物形式之金屬硫酸鹽： A12(S04)3+6[(CH3)4N]0H_4 2A1(〇h)3+3[(CH3)4N]2(S04) 在約4與12之pH之間形成完全不溶性懸浮鋁沉澱物。 適用於本發明之金屬氫氧化物包括（但不限於）、 氫氧化錳、氫氧化鋁及Zn(〇H；)2。 可作為懸浮顆粒或於原位形成以作為懸浮顆粒之金屬氧 化物或氧化物水合物係Mn〇2、Mg〇、Zn〇、SnQ2xH2〇、201215670 VI. Description of the Invention: TECHNICAL FIELD OF THE INVENTION The present invention relates to a long-term stable aqueous or semi-aqueous slurry suspension. More particularly, the present invention provides aqueous and semi-aqueous slurries having long-term stability characteristics (referred to as soft precipitation characteristics) that can be used to include abrasive applications, wire saw cutting, CMP (chemical mechanical polishing / planarization) Metal fabrication and polishing, and abrasive-free grinding in a variety of commercial applications. [Prior Art] The non-aqueous, semi-aqueous and suspending (four) non-colloidal high-density abrasive particles have been previously cut and ground in the line of the crystal K, but a stable slurry cannot be obtained. U.S. Patent No. 5,99,82, to Stricot, discloses a pulverizing slurry of a cerium carbide particle suspension containing water or oil. However, such suspensions are unstable and do not provide uniform lubrication and cutting by the wires. These compositions require vigorous agitation to maintain a uniform suspension of the particles, and the suspension precipitates rapidly under standing conditions even during the cutting of the workpiece while still under agitation. The copending patent application No. 9/637'263 to the iWard et al., which is hereby incorporated by reference in its entirety in its entirety in A non-aqueous or semi-aqueous cutting and lubricating composition for use with wire saws that relies on surfactants, polyelectrolytes, and cations to provide electrostatic repulsion and interparticle interference to maintain a stable suspension of abrasive particles. U.S. Patent No. M54,422, issued to Ward et al., discloses the disclosure of the disclosure of the disclosure of the disclosure of the disclosure of the disclosure of the disclosure of the disclosure of the disclosure of the disclosure of the disclosure of the disclosure of the disclosure of the disclosure of It contains up to 70% by weight of scrub material. Used in industrial applications (ie, microelectronics, solar cells, LED's, wide bandwidth devices, optics/lasers, wafer polishing, CMP applications, and many other applications), Sic, Sapphire, GaAs, In the manufacture of optical glass and other wafers, wafers are cut from larger ingots, bricks, and pears. The next step after the initial dicing of the wafer, disk, workpiece, etc., includes grinding of the dicing wafer to smooth the surface, reduce TTV, eliminate damaging depth defects, and prepare a crystal for final "polishing." In general, an aqueous carrier is used as the suspension medium for the abrasive used in this step. Abrasives can include, but are not limited to, Sic, alumina, Zr 〇 2, vermiculite, diamond, and the like. The abrasive slurry uses abrasive particles ranging in size from about 0.5 to 20 μm. This means that the suspended abrasive particles are generally non-colloid in size and nature. This does not preclude the use of colloidal abrasives (i.e., abrasive particles having a size in the range of about o.oomo μηι), and particles such as Xinxuan are generally not used in the abrasive slurry. During the wafer polishing process, the abrasives used in wafers, enamels, ceramics, etc. are subjected to a number of shearing, polishing, and grinding forces. During the "plane grinding" process, the slurry is injected onto the surface of the wafer that is fixed between two large iron pieces. The reverse rotation of the upper and lower sheets of the wafer is fixed, and the loading between the upper sheet and the surface of the wafer is fixed. The solid within the compressed polymer contacts the wafer and the angular momentum causes the abrasive to move to remove surface wafer defects and "money" the desired amount of wafer surface material. Utilizing all of the aqueous slurry currently used for grinding, the design of the activity and grinding equipment on the (4) causes the particles to coalesce on the wafer, in the reservoir, in the supply pipe, and on the 151248.doc 201215670 " on-chip, etc. . The coalescence of the particles additionally has the deleterious effect of damaging "to rub" on the abrasive wafer. These high cost wafers must then be discarded. Aqueous suspensions of non-colloidal (i.e., NCOL) high density abrasive particles have been a serious and thorny problem for "wafer" manufacturers for decades. To date, there are no low viscosity aqueous carriers that will hold the "NCOL" abrasive particle suspension for a short period of time: a few minutes. Thereafter, the particles begin to coalesce and quickly sink from the suspension to the bottom of the container. Even during continuous mixing: or recycling, the abrasive particles still precipitate in existing "aqueous" aggregates. This pellet precipitation is usually shown as a "hard precipitated mass" at the bottom of the vessel. Any attempt to maintain a slurry of the initial particle size distribution of the original abrasive = 2 can not be accomplished by simple mixing, (d), shaking or the like. Therefore, the slurry is quickly discarded, which wastes expensive abrasives, labor, and effort. • In prior art suspensions, the temperature and positive impact suspensions remained homogeneous and consistent during long-term storage. The inorganic particles may remain suspended in an aqueous and non-aqueous solvent (which depends on the size, lattice structure and density of the particles), but tend to agglomerate and settle in the suspension in the static storage. [Invention] A suspension of an I machine or a ceramic granule contained in an aqueous or semi-aqueous carrier maintained at ambient temperature and elevated temperature and in a broad pH range comprising a pH of from about 7 to 8.5. According to the present invention, particles such as sols, gels, gels, precipitates and the like are used to cause abrasive particles to interfere with each other in an aqueous or semi-aqueous carrier environment (it is believed that they are also produced in the environment 151248.doc s 201215670) Stabilize the repulsion potential and suspend. The slurry composition may contain from about 1 to 70% by weight of the inorganic or ceramic abrasive material and from about 至 to 2% by weight of the normally formed suspended particles, which are in the pH range of about 4 to 12 The water forms a composition of other metal oxides, hydroxides, and oxide hydrates of suspended matter. The aqueous content of the carrier may contain from about 5 to about 00% by weight water and is inert and does not complement the aqueous medium and the organic solvent comprising the suspended particles of the abrasive material to make up the remainder. The density of the suspended particles is approximately equal to or less than the carrier solvent composition. The overall object of the present invention is to provide long-term stable abrasive slurry suspensions for wire saw applications, grinding applications, CMP applications, and the like that can be used for self-casting and cutting sheets. Another object of the present invention is to provide a long-term stable suspension of abrasive particles contained in a low toxicity carrier. A further object of the present invention is to provide a stable suspension of colloid or NCOL abrasive or other particles contained in a neutral or near neutral medium. Another object of the present invention is to provide a non-viscous-dependent method of suspending colloidal or NCOL abrasives or other particles in a liquid. [Embodiment] The present invention provides a method for providing a stable county float containing particles in an aqueous or semi-aqueous medium having a long static storage period without agglomeration or abrasive grain hardening. According to a feature of the invention, it provides a lubricating carrier and a abrasive mass composition (which is used in wireline applications (eg, cutting ingots or pear crystals into wafers or disks for use in semiconductor or optoelectronic devices) The carrier is maintained in a 28 position environment) 'grinding or polishing charge, (10) grinding residue and similar 151248.doc 201215670, wherein the particle suspension is maintained at ambient temperature and elevated temperature. By providing about (U to 20% by volume of suspended particles (which provide anti-agglomerates or hard-sinking particles (four) pre-and (4) at or near the (four) (four) particle density) 'the abrasive particles Maintaining as an aqueous or semi-aqueous slurry. The suspended particles are formed at a pH of about 4 to 12 to form a metal oxide of suspended particles (ie, sol, gel, gelatinous precipitate, etc.) in water. Hydroxides and oxide hydrates. These abrasive particles include a particle size of about 3 to 100 μηιιη for wire-cutting, metal polishing applications, typically in the lower range of about 0.5 to 20 μm for wafer grinding applications. Internal and CMp applications are conventional abrasive particles typically in the lower range of about 50 to 1.0 nm. Preferably, the suspended particles are in the form of a metal former. In this case, the density of the precipitated particles prepared in situ is generally lower and the surface area of the particles is larger than that of the commercially available in situ precipitated form. In addition, the suspended particles formed in situ are usually Has a wider particle size distribution. Used in the above composition The abrasive material may comprise diamond, vermiculite 'tungsten carbide, tantalum carbide, boron carbide, tantalum nitride, yttria, oxidized hammer, alumina powder; or other hard sand "powder" material. One of the most commonly used abrasive materials In the case of wire sawing applications, the average particle size is in the range of about 0.5 to 30 microns 'and preferably 3 to 20 microns, which is based on the international "FEPA or JIS" rating of the sand powder. The concentration of the abrasive in the suspension medium or carrier for wire sawing applications can generally range from about 0.1 to 60 weight percent abrasive, and the particle size is from about 0.2 to 50 μηι and preferably from about 1 to 3. Within the range of 〇μιη. For metal polishing or grinding 151248.doc η 201215670 grinding applications, the abrasive size is in the range of about 6 to 200 0111 and preferably about 1 〇 to 1 〇〇 μηη. In the case of chemical mechanical polishing/planarization, the abrasive particle size can generally be in the range of about 10 to 2 〇〇〇 nm (nano) and preferably about 5 〇 to 800 nm (nano). Abrasive grain size can usually be from about 2 to 70μ And preferably in the range of about 6 to 50 μm. The solvent which can be used together with water is a polar solvent comprising alcohol, guanamine, vinegar, test, hydrazine, diol, di(four), in-hospital, or sub-hard Examples of polar solvents are dimethyl sulfoxide, dimethylacetamide (DMAC), N-decyl pyrrolidone (ΝΜρ), (γ) butyrolactone, diethylene glycol early diethyl ether, dipropylene glycol monoterpene Ether, tripropylene glycol monomethyl ether 'various polyethylene glycols and polypropylene glycols and the like. These organic solvents are used in some cases to provide the necessary viscosity levels for the resulting slurry. Other uses of organic solvents may include lowering The freezing point of the slurry/carrier. The choice of solvent is relatively unimportant as long as the solvent is inert, does not react with water or suspended abrasive particles and has low toxicity and low odor. Suspended particles that can be used include, but are not limited to, metal hydroxides, oxides that form aqueous or semi-aqueous suspensions (ie, gels, gelatinous precipitates, sols, colloidal or non-colloidal suspensions, solid emulsions, etc.) Hydrate and milled particulate oxide. These suspended particles will not precipitate as a significant component of the present invention over time. These include, but are not limited to, compounds which are converted in situ to a hydroxide form within or outside the medium', for example, as exemplified by the following example, which utilizes a metal or non-metal Br()nstead test (eg, hydroxide) Unloading 'tetramethyl hydroxide hydroxide, sodium hydroxide, hydroquinone tetraethyl sulphate, hydrazine lock 15 248.doc 201215670, etc.) converted to hydroxide form of metal sulphate: A12 (S04) 3 + 6 [(CH3)4N]0H_4 2A1(〇h)3+3[(CH3)4N]2(S04) A completely insoluble suspended aluminum precipitate is formed between pHs of about 4 and 12. Metal hydroxides suitable for use in the present invention include, but are not limited to, manganese hydroxide, aluminum hydroxide, and Zn(〇H;)2. It can be used as a suspended particle or a metal oxide or oxide hydrate system Mn〇2, Mg〇, Zn〇, SnQ2xH2〇 which is formed as a suspended particle in situ.
Ti〇2、Α12〇3.χΗ2〇及類似物。該等氧化物亦可用於原位提 供相應之氫氧化物，以為載體系統提供穩定懸浮溶膠、凝 膠、膠狀或膠體或非膠體懸浮液。 在Al(OH)3或其他鋁氧化物或氫氧化物種類之情況下， 用於該載體之pH範圍係約4至12。較佳範圍係5 5至9且最 佳範圍係7至8.5 ^在最佳範圍内，據信在該等顆粒周圍存 在穩定ζ電位環境，其增加該系統内顆粒之相互排斥力。 懸浮沉澱物或顆粒不包括彼等密度顯著大於載體溶劑之 顆粒、及彼等非天然沉澱或可懸浮者。應瞭解存在彼等除 在忒載體溶劑中或在隨後添加至本發明載體系統之另一介 質中原位形成或’/儿殿時以外具有較高密度之金屬氧化物或 氫氧化物。 為在數量上測定研磨漿料（即SiC漿料）之「軟沉澱」特 徵水平，PPT研究化學家及工程師使用精確測量工具。特 定載體之漿料穩定性係藉由其軟沉澱特性（SSR)或（換言之） 固體懸浮液對於在容器底部形成硬塊之抵抗性、及懸浮體 積保留性（SVR)(其測量固體顆粒在懸浮液中之保留程度） 151248.doc 201215670 測量。為測定載體是否能夠形成穩定漿料，製備含有15°Λ 碳化矽（SiC)(JlS 1000等級）（即平均粒度在約13至16 ^^之 間）之漿料並儲存於環境溫度及5(rc下之5〇 mL離心管中， 並在長時間内測量該5^及SVR。使用IMADa VerticalTi〇2, Α12〇3.χΗ2〇 and the like. The oxides can also be used to provide corresponding hydroxides in situ to provide a stable suspension sol, gel, gel or colloidal or non-colloidal suspension for the carrier system. In the case of Al(OH)3 or other aluminum oxide or hydroxide species, the pH range for the support is from about 4 to about 12. The preferred range is from 5 5 to 9 and the optimum range is from 7 to 8.5. Within the optimum range, it is believed that there is a stable zeta potential environment around the particles which increases the mutual repulsive force of the particles within the system. The suspended precipitates or granules do not include those particles having a density substantially greater than the carrier solvent, and those which are not naturally precipitated or suspensable. It will be appreciated that there are metal oxides or hydroxides which have a higher density than those which are formed in situ in the ruthenium carrier solvent or in another medium which is subsequently added to the carrier system of the present invention. In order to quantitatively determine the "soft precipitation" characteristic level of the abrasive slurry (i.e., SiC slurry), PPT research chemists and engineers use accurate measurement tools. The slurry stability of a particular carrier is based on its soft precipitation properties (SSR) or (in other words) the stability of the solid suspension on the formation of lumps at the bottom of the vessel, and the suspension volume retention (SVR) (which measures the solid particles in suspension) The degree of retention in the 151248.doc 201215670 measurement. To determine if the support is capable of forming a stable slurry, a slurry containing 15° 碳 SiC (JlS 1000 grade) (ie, having an average particle size between about 13 and 16 ^^) was prepared and stored at ambient temperature and 5 ( The 5 〇mL centrifuge tube under rc and measure the 5^ and SVR over a long period of time. Using IMADa Vertical
Manual Lever F〇rce Test Stand，Model LV-100測量軟沉 屣。該IMADA測量在軸底部具有標準直徑圓墊之探針穿過 該漿料並到達該管之底部所需之力。為測量該力，藉由加 長該探針軸改進該IMADA之設備，以使該探針可在丨mm 以内到達該離心管之錐形底部。藉由將長螺桿連接至該探 針來加長該探針。*IMADA測量之力係精確至百分之一 磅。低SSR顯示可容易使該磨料再懸浮，且如之高數 值顯不該磨料已硬沉澱且不容易再懸浮。 藉由/則量固體在該離心管内佔有之體積（以Μ計），將該 體積除以該離心管内之漿料之總體積（以ml計）並乘以100 來汁才該SVR。該SVR值越高（接近100%)，則載體保持磨 2懸浮之能力越好。漿料之SVR通常隨時間減少，且不一 ’”員示及聚料之軟沉澱特性。每天檢查該SSR及SVR，歷 時週’之後每週檢查一次。 因此，該工具以可重複及精確之方式測量「塊狀物抗穿 透陡」每天檢查標準棒穿透深度及該工具之校準。就於 極佳懸汙液載體内形成之漿料而言，預期抗穿透性之「軟 T殿讀數」（即SSR)較低；在控制賴條件下之長儲存期 (4週）内為<0·2 ibs.。就於較差懸浮液載體（例如標準 PEG-200、3〇〇、或4〇〇、或水）内形成之漿料而言在極短 15J248.doc 201215670 之儲存」日夺間内，SSR通常在。至^即高值）之範圍 ^換言之’給定漿料隨時間之SSR越低，則該漿料越穩 疋均勻，且就自性能至儲存能力至漿料懸浮保持力至可 回收利用性之各項而言越佳。 由於本發明係M於水性及半水性介f，因此本發明調配 物與諸如碳鋼、鐵、彈簧鋼等金屬（其為線鑛、金屬抛光 研磨機曰曰圓研磨機等之通常組分）之持續接觸可導致該 等金屬之腐蝕或生銹，可採取添加阻蝕劑。 本發月之另一目標係提供一種不腐钱諸如鐵'碳鋼等金 屬之水性或半水性載體/漿料系統。 可將阻姓劑添加至本發明載體調配物中，以抑制或消除 金屬腐蝕。合適之抑制劑不應引起起泡，干擾調配物提供 長期穩定性磨料或固體懸浮液之能力，及損害該等載體調 配物及其相關之磨料或固體懸浮液之黏度、流變性、pH、 或均勻性。 可添加至本發明水性或半水性載體中之合適阻蝕劑包括 (但不限於）脂肪族及芳族緩酸、使用烧醇胺（即二乙醇胺、 二乙醇胺等）中和之羧酸、烷胺或芳族胺或Bronstead—。 亦可包含相關技術中已知之其他金屬阻蝕劑，例如商標名 為（諸如）DeForest DeCore-APCI-95、DeTrope CA-100之經 長鏈修飾之市售羧酸酯。同樣適用於防止或抑制CMP方法 中所用之金屬（即 Al/Cu ' Cu、Al/Si、Al/Si/Cu、GaAs、 LnP、及類似物）之腐蝕的習知阻蝕劑之其他實例可包括 (但不限於）苯甲酸、焦掊驗、沒食子酸、硫代硫酸銨、8-151248.doc 201215670 羥基喹啉、兒茶酚、笨并三唑等。 另外’存在其他作為氧吸㈣或清除劑之合適阻敍劑， 其包括（但不限於）經基啥琳、8_經基㈣、亞硝㈣亞 硫酸酯等。 針對本發明目標之該等阻蝕劑之選擇並不重要，只要該 抑制劑符合以上所述之性能標準即可，其包括·_ -抑制或消除金屬腐蝕； -不引起載體或所得之漿料之明顯起泡； •不損害或干擾該载體提供長期漿料穩定性之能力； 不有害地衫響该載體或所得之研磨固體懸浮液之黏 度、pH或流變性； -不有害地影響該載體懸浮液或含於該載體中之研磨固 體懸浮液之均勻性或均質性。 以下實例闡述本發明方法之實踐。然而，應瞭解並不意 欲以任何限制本發明之整體範圍之方式解釋所列之實例， 因為本文含有根據上述指導原則之多種變化。除非另有說 明’否則本文所述之所有百分比皆以重量計。 實例1 將十六水合硫酸鋁之0.5 Μ水溶液添加至自來水中，以 使水中之硫酸铭百分比係〇 94〇/〇。藉由〇 5 μ氫氧化四甲基 銨（ΤΜΑΗ)溶液將該溶液中和至ρΗ 7.52。列出該調配物之 軟沉澱讀數（SSR)及懸浮體積保留性（SVR)數據。該SSRi 「零」讀數顯示極佳懸浮液。在4週之最後之「2〇」之 SVR係與良好「軟沉澱」懸浮液一致。 151248.doc 12 201215670 表la調配物數據 %固體 g g0.4M g0.5M pH Al2(S〇4)316 h2o 自來水 (AI2(S〇4)3 TMAH 0.94 300.00 9.75 43.24 7.52 表lb黏度、SSR、及SVR數據 %固體 AI2(S〇4)3.16H20 環境溫度軟沉澱及SVR 50°C軟沉澱及SVR 第1天 第4週 第1天 第4週 0.94 SVR SSR SVR SSR SVR SSR SVR SSR 29 0 22 0 28 0 20 0 實例2 將固體十六水合硫酸鋁添加至自來水中，以使硫酸鋁在 水中之濃度係1〇·76%。藉由TMAH(25%水溶液）將該溶液 中和至pH 7.69。該調配物、黏度、SSR及SVR數據係列於 下表中。即使在4週之後，SSR及SVR讀數仍再次顯示極佳 之穩定研磨顆粒懸浮液。 表2a調配物數據 %固體 Al2(S〇4)3.16H20 G 自來水 g固體 (Al2(S〇4)3 g25% TMAH pH 10.76 267.73 32.24 99.25 7.69Manual Lever F〇rce Test Stand, Model LV-100 measures soft sinking. The IMADA measures the force required to pass a probe of a standard diameter dome at the bottom of the shaft through the slurry and to the bottom of the tube. To measure this force, the IMADA device is modified by lengthening the probe shaft so that the probe can reach the conical bottom of the centrifuge tube within 丨mm. The probe is lengthened by attaching a long screw to the probe. * The force measured by IMADA is accurate to one hundredth of a pound. The low SSR shows that the abrasive can be easily resuspended, and as the high number indicates that the abrasive has hard precipitated and is not easily resuspended. The SVR is obtained by dividing the volume occupied by the solid in the centrifuge tube (in twips) by dividing the volume by the total volume of the slurry in the centrifuge tube (in ml) and multiplying by 100. The higher the SVR value (close to 100%), the better the ability of the carrier to maintain the mill 2 suspension. The SVR of the slurry usually decreases with time, and does not indicate the soft precipitation characteristics of the material. The SSR and SVR are inspected every day and are checked once a week after the week. Therefore, the tool is repeatable and accurate. Method of measuring "block resistance to penetration" daily inspection of the standard rod penetration depth and calibration of the tool. For the slurry formed in the excellent suspension liquid carrier, the "soft T-reading" (ie, SSR) for anti-penetration is expected to be low; in the long storage period (4 weeks) under controlled conditions <0·2 ibs. For slurries formed in poor suspension carriers (eg standard PEG-200, 3〇〇, or 4〇〇, or water), the SSR is usually in the very short storage period of 15J248.doc 201215670. . Range to ^, ie high value) ^ In other words, the lower the SSR of a given slurry over time, the more stable and uniform the slurry, and from the performance to the storage capacity to the slurry suspension retention to recyclability The better each item. Since the present invention is based on an aqueous and semi-aqueous medium, the formulation of the present invention and a metal such as carbon steel, iron, spring steel (which is a common component of a wire ore, a metal polishing grinder, a round grinder, etc.) Continued contact can cause corrosion or rusting of such metals, and the addition of a corrosion inhibitor can be employed. Another objective of this month is to provide an aqueous or semi-aqueous carrier/slurry system that does not burn money such as iron 'carbon steel. A dragging agent can be added to the carrier formulation of the present invention to inhibit or eliminate metal corrosion. Suitable inhibitors should not cause foaming, interfere with the ability of the formulation to provide long-term stability of the abrasive or solid suspension, and impair the viscosity, rheology, pH, or the viscosity of the carrier formulation and its associated abrasive or solid suspension. Uniformity. Suitable corrosion inhibitors which may be added to the aqueous or semi-aqueous carrier of the present invention include, but are not limited to, aliphatic and aromatic acid retardants, carboxylic acids, alkane neutralized with an alcoholic amine (i.e., diethanolamine, diethanolamine, etc.). Amine or aromatic amine or Bronstead-. Other metal corrosion inhibitors known in the art may also be included, such as long-chain modified commercial carboxylic acid esters of the trade names such as DeForest DeCore-APCI-95, DeTrope CA-100. Other examples of conventional corrosion inhibitors that are equally suitable for preventing or inhibiting corrosion of metals used in CMP processes (ie, Al/Cu 'Cu, Al/Si, Al/Si/Cu, GaAs, LnP, and the like) may be Including, but not limited to, benzoic acid, pyrolysis, gallic acid, ammonium thiosulfate, 8-151248.doc 201215670 hydroxyquinoline, catechol, stupid triazole and the like. Further, there are other suitable anti-suppressants as oxygen (4) or scavengers including, but not limited to, quinone, 8-trans (4), nitros (tetra) sulfite, and the like. The selection of such corrosion inhibitors for the purposes of the present invention is not critical as long as the inhibitor meets the performance criteria described above, including: - inhibiting or eliminating metal corrosion; - not causing the carrier or the resulting slurry Significant foaming; • does not impair or interfere with the ability of the carrier to provide long-term slurry stability; does not deleteriously smear the viscosity, pH or rheology of the carrier or the resulting ground solid suspension; - does not adversely affect the The uniformity or homogeneity of the carrier suspension or the ground solid suspension contained in the carrier. The following examples illustrate the practice of the method of the invention. However, it is to be understood that the examples are not to be construed as limiting the scope of the invention as the All percentages stated herein are by weight unless otherwise indicated. Example 1 An aqueous solution of 0.5 Torr of aluminum sulfate hexadecahydrate was added to tap water so that the percentage of sulphuric acid in water was 〇94 〇/〇. The solution was neutralized to pH Η 7.52 by 〇 5 μ of tetramethylammonium hydroxide (hydrazine) solution. The soft sedimentation reading (SSR) and suspension volume retention (SVR) data for this formulation are listed. The SSRi "zero" reading shows an excellent suspension. At the end of the 4th week, the "2" SVR system was consistent with a good "soft precipitate" suspension. 151248.doc 12 201215670 Table la Formulation data % solid g g0.4M g0.5M pH Al2(S〇4)316 h2o Tap water (AI2(S〇4)3 TMAH 0.94 300.00 9.75 43.24 7.52 Table lb viscosity, SSR, and SVR data % solid AI2 (S〇4) 3.16H20 Ambient temperature soft precipitation and SVR 50 °C soft precipitation and SVR Day 1 Week 4 Day 1 Week 4 0.94 SVR SSR SSR SSR SVR SSR SVR SSR 29 0 22 0 28 0 20 0 Example 2 Solid aluminum hexahydrate hexahydrate was added to tap water so that the concentration of aluminum sulfate in water was 1 〇 76%. The solution was neutralized to pH 7.69 by TMAH (25% aqueous solution). The formulation, viscosity, SSR and SVR data series are in the table below. Even after 4 weeks, the SSR and SVR readings again showed excellent stable abrasive particle suspension. Table 2a Formulation data % solid Al2 (S〇4 ) 3.16H20 G tap water g solid (Al2(S〇4)3 g25% TMAH pH 10.76 267.73 32.24 99.25 7.69
表2b黏度、SSR及SVR %固體 Al2(S〇4)3 250下 i (c] 匕黏度 Ε») 環境溫度軟沉澱及SVR 50°C軟沉澱及SVR 載體 漿料 第1天 第4週 第1天 第4週 SVR SSR SVR SSR SVR SSR SVR SSR 10.76 16.0 74.0 66 0 42 0 56 0 51 0 實例3 將固體十六水合硫酸鋁添加至自來水中以使硫酸鋁在水 中之濃度係15.54%。藉由TMAH(25%水溶液）將該溶液中 151248.doc -13- 201215670 和至pH 7.73。該調配物、黏度、SSR及SVR數據係列於下 表中。就漿料穩定性而言，觀察到與先前實例相似之結 果。然而，在此實例中，4週後50°C下之74之SVR顯示極 穩定之裝料。 表3a調配物數據 %固體 Al2(S〇4)3 g 自來水 g固體 (A12(S04)3 g25% ΤΜΑΗ PH 15.54 253.37 46.62 146.03 7.73 表3b黏度、SSR及SVR數據 %固體 Al2(S〇4)3 25°下之黏度 (cP) 環境溫度軟沉澱及SVR 50°C軟沉澱及SVR 載體 漿料 第1天 第4週 第1天 第4週 SVR SSR SVR SSR SVR SSR SVR SSR 15.54 29.4 236.5 71 0 58 0 71 0 74 0 實例4 在此實例中，使用採用二甘醇（DEG)之半水性溶劑代替 自來水作為溶劑。由於硫酸銘不溶於DEG，因此在將其添 加至該DEG中之前必須製備硫酸铭之水溶液。在此情況 下，製備0.4 Μ硫酸鋁溶液並添加至該DEG中。隨後藉由 ΤΜΑΗ之25%水溶液增加pH。測量SSR、SVR及黏度。藉 由利用15%氧化錯（Zr〇2)代替SiC來製備軟沉澱管。結果係 列於下表中。表4b之SSR結果顯示在環境溫度下，當該 A1(S04)3_16H20之起始量超過2.0%時，一週後存在穩定懸 浮液。在此情況下，SSR=0.16，其顯示「軟沉澱性」極高 之穩定懸浮液。在50°C下，即使0.49%之A1S水平在一週後 仍形成穩定懸浮液。 151248.doc 14 201215670 表4a調配物數據 %固體 Al2(S〇4)3 % 0.4 Μ Al2(S〇4)3 DEG*之重量 (g) 0.4 M Al2(S〇4)3 之重量 (ε) 25% ΤΜΑΗ 之重量 (s) pH 0.49 2.03 386.16 7.99 5.84 8.01 0.99 4.12 703.91 30.25 22.09 8.05 1.50 6.28 589.22 39.45 28.83 7.80 2.03 8.50 566.14 52.57 38.42 7.79 2.58 10.77 336.74 40.66 29.20 8.80 *DEG=二甘醇 表4b SSR及SVR數據 %固體 Al2(S〇4)3 25。。— F之黏度(cP) 環境溫度SSR及SVR 50°C SSR及SVR 載體 含有18% Zr02之漿料 第1天 第1週 第1天 第1週 SSR SSR SSR SSR 0.49 31 212 0 1.16 0 0.21 0.99 49 218 0 1.24 0 0 1.50 27 217 0 1.03 0 0.51 2.03 34 353 0 0.16 0 0 2.58 32 330 0 0 0 0 實例5 以下調配物之目的係藉由以自來水稀釋該載體來降低實 例4中所描述之調配物之黏度。藉由水將該載體稀釋25% 及50%，並使硫酸鋁之濃度在各種稀釋液之間保持恆定。 就此實例而言，下表指出50%稀釋液。藉由利用18%氧化 锆（Zr02)代替SiC來製備軟沉澱管。結果係列於下表中。 表5a調配物數據 °/。固體 Al2(S〇4)3 實例4之載體之重量 (g) 自來水之重量 (ε) pH 0.25 140 140 7.77 0.50 140 140 7.86 0.75 140 140 7.63 1.01 140 140 7.71 1.29 140 140 7.61Table 2b Viscosity, SSR and SVR % Solid Al2(S〇4)3 250 i (c) 匕 Viscosity Ε») Ambient temperature soft precipitation and SVR 50 °C soft precipitation and SVR carrier slurry Day 1 Week 4 Day 4 Week 4 SVR SSR SVR SSR SVR SSR SVR SSR 10.76 16.0 74.0 66 0 42 0 56 0 51 0 Example 3 Solid aluminum hexahydrate hexahydrate was added to tap water so that the concentration of aluminum sulfate in water was 15.54%. The solution was 151248.doc -13 - 201215670 and to pH 7.73 by TMAH (25% aqueous solution). The formulation, viscosity, SSR and SVR data series are listed below. In terms of slurry stability, similar results to the previous examples were observed. However, in this example, the SVR of 74 at 50 °C after 4 weeks showed an extremely stable charge. Table 3a Formulation data % solid Al2(S〇4)3 g Tap water g solid (A12(S04)3 g25% ΤΜΑΗPH 15.54 253.37 46.62 146.03 7.73 Table 3b Viscosity, SSR and SVR data % solid Al2(S〇4)3 Viscosity at 25° (cP) Ambient Temperature Soft Precipitation and SVR 50°C Soft Precipitation and SVR Carrier Slurry Day 1 Week 4 Day 1 Week 4 SVR SSR SVR SSR SVR SSR SVR SSR 15.54 29.4 236.5 71 0 58 0 71 0 74 0 Example 4 In this example, a semi-aqueous solvent using diethylene glycol (DEG) was used instead of tap water as a solvent. Since sulfuric acid is insoluble in DEG, it must be prepared before adding it to the DEG. In this case, a 0.4 Μ aluminum sulfate solution was prepared and added to the DEG. The pH was then increased by a 25% aqueous solution of hydrazine. The SSR, SVR and viscosity were measured. By using 15% oxidative error (Zr〇2) The soft precipitation tube was prepared instead of SiC. The results are summarized in the table below. The SSR results in Table 4b show that at ambient temperature, when the starting amount of A1(S04)3_16H20 exceeds 2.0%, a stable suspension is present after one week. In this case, SSR = 0.16, which shows that "soft precipitation" is extremely high. Stable suspension. Stable suspension formed at 50 ° C even after 0.49% of A1S level. 151248.doc 14 201215670 Table 4a Formulation data % solid Al2(S〇4)3 % 0.4 Μ Al2(S 〇4)3 Weight of DEG* (g) 0.4 M Al2(S〇4)3 Weight (ε) 25% ΤΜΑΗ Weight (s) pH 0.49 2.03 386.16 7.99 5.84 8.01 0.99 4.12 703.91 30.25 22.09 8.05 1.50 6.28 589.22 39.45 28.83 7.80 2.03 8.50 566.14 52.57 38.42 7.79 2.58 10.77 336.74 40.66 29.20 8.80 *DEG=diethylene glycol Table 4b SSR and SVR data % solid Al2(S〇4)3 25. —F viscosity (cP) Ambient temperature SSR and SVR 50°C SSR and SVR carrier containing 18% Zr02 slurry Day 1 Day 1 Day 1 Week 1 SSR SSR SSR SSR 0.49 31 212 0 1.16 0 0.21 0.99 49 218 0 1.24 0 0 1.50 27 217 0 1.03 0 0.51 2.03 34 353 0 0.16 0 0 2.58 32 330 0 0 0 0 Example 5 The following formulation was intended to reduce the viscosity of the formulation described in Example 4 by diluting the carrier with tap water. The carrier was diluted 25% and 50% with water and the concentration of aluminum sulfate was kept constant between the various dilutions. For this example, the table below indicates a 50% dilution. A soft precipitation tube was prepared by using 18% zirconia (ZrO 2 ) instead of SiC. The results are listed in the table below. Table 5a Formulation data °/. Solid Al2(S〇4)3 The weight of the carrier of Example 4 (g) The weight of tap water (ε) pH 0.25 140 140 7.77 0.50 140 140 7.86 0.75 140 140 7.63 1.01 140 140 7.71 1.29 140 140 7.61
S 151248.doc -15- 201215670 表5b黏度、SSR及SVR數據 %固體 Al2(S〇4)3 25〇C下之黏度(cP) 環境溫度SSR及SVR 50〇C SSR及SVR 載體 含有18°/。 Zr02之漿料 第1天 第1週 第1天 第1週 SSR SSR SSR SSR 0.25 6 63 0 1.3 0 1.6 0.50 8 73 0 1.5 0 1.16 0.75 10 86 0 0.76 0 0.53 1.01 9 87 0 1.1 0 0.14 1.29 16 185 0 0.73 0 0 表5b之SSR結果顯示當該硫酸鋁％含量20.75%時之環境 溫度漿料之「軟沉澱」特性之最低可接受讀數。在50°C 下，當該硫酸鋁％含量>0.50%時，一週後，SSR顯示穩定 「軟沉澱」聚料。 實例6 本實例研究是否可使用金屬氫氧化物鹼（如KOH)代替在 其他實例中使用之非金屬鹼TMAH。藉由首先製備0·1 Μ硫 酸鋁溶液，隨後將該溶液添加至去離子水中，以使該0.1 Μ 硫酸鋁在溶液中之濃度為10重量％來製備該載體。隨後藉 由0.1 Μ ΚΟΗ中和該溶液直至該溶液之pH為8.05。結果係 列於下表中。由此實例明顯可知，即使在儲存4週之後， 金屬氫氧化物鹼仍將形成非常穩定之水性磨料懸浮液。 表6a調配物數據 %固體 Al2(S〇4)3 g 去離子水 gO.lM Al2(S〇4>3 gO.lM KOH pH 0.60 90.01 10.00 50.90 8.05 表6b SSR及SVR數據 環境溫度軟沉澱及SVR 50°C軟沉澱及SVR 第1天 第4週 第1天 第4週 SVR SSR SVR SSR SVR SSR SVR SSR 26 0 17 0 21 0 20 0 151248.doc -16- 201215670 比較例 此實例測試pH是否確實需要大於4。製備0.1 Μ十六水合 硫酸鋁水溶液並添加至DI水中。該0.1 Μ硫酸鋁溶液在此 載體中之濃度為1〇重量％ Al(S〇4)3 · 16Η20。最終pH為約4。 如先前實例中所述，製備及監測軟沉澱管。結果係列於下 表中。此最終列舉之實例之結果顯示：在環境溫度及50°C 下，當pH低至4.0時，該等SSR值即使在4週後仍顯示「軟 沉澱性」穩定漿料懸浮液。 SSR及SVR數據表 環境溫度軟沉澱及SVR 50°C軟沉澱及SVR 第1天 第4週 第1天 第4週 SVR SSR SVR SSR SVR SSR SVR SSR 14 0.21 11 0.69 11 0.66 11 0.65 151248.doc 17-S 151248.doc -15- 201215670 Table 5b Viscosity, SSR and SVR Data % Solid Al2(S〇4)3 Viscosity at 25〇C (cP) Ambient Temperature SSR and SVR 50〇C SSR and SVR Carrier Contains 18°/ . Zr02 slurry Day 1 Day 1 Day 1 Week 1 SSR SSR SSR SSR 0.25 6 63 0 1.3 0 1.6 0.50 8 73 0 1.5 0 1.16 0.75 10 86 0 0.76 0 0.53 1.01 9 87 0 1.1 0 0.14 1.29 16 185 0 0.73 0 0 The SSR results in Table 5b show the lowest acceptable readings for the "soft precipitation" characteristics of the ambient temperature slurry when the aluminum sulfate content is 20.75%. At 50 ° C, when the % aluminum sulfate content was > 0.50%, one week later, the SSR showed a stable "soft precipitated" polymer. Example 6 This example investigates whether a metal hydroxide base such as KOH can be used in place of the non-metal base TMAH used in other examples. The support was prepared by first preparing a 0.11 bismuth aluminate solution, which was then added to deionized water so that the concentration of the 0.1 Å aluminum sulfate in the solution was 10% by weight. The solution was then neutralized by 0.1 Torr until the pH of the solution was 8.05. The results are listed in the table below. It is apparent from this example that the metal hydroxide base will form a very stable aqueous abrasive suspension even after 4 weeks of storage. Table 6a Formulation data % solid Al2(S〇4)3 g Deionized water gO.lM Al2(S〇4>3 gO.lM KOH pH 0.60 90.01 10.00 50.90 8.05 Table 6b SSR and SVR data ambient temperature soft precipitation and SVR 50 °C soft precipitation and SVR Day 1 Week 4 Day 1 Week 4 SVR SSR SVR SSR SVR SSR SVR SSR 26 0 17 0 21 0 20 0 151248.doc -16- 201215670 Comparative Example This example tests whether the pH is indeed It is required to be greater than 4. A 0.1 Μ aqueous solution of aluminum sulphate hexahydrate is prepared and added to DI water. The concentration of the 0.1 Μ aluminum sulfate solution in the carrier is 1% by weight of Al(S〇4)3 · 16Η20. The final pH is about 4. Prepare and monitor the soft precipitation tube as described in the previous examples. The results are summarized in the table below. The results of this final example show that at ambient temperature and 50 ° C, when the pH is as low as 4.0, The SSR value shows a "soft-precipitating" stable slurry suspension even after 4 weeks. SSR and SVR data sheet ambient temperature soft precipitation and SVR 50 °C soft precipitation and SVR Day 1 Week 4 Day 1 Week 4 SVR SSR SVR SSR SVR SSR SSR SSR 14 0.21 11 0.69 11 0.66 11 0.65 151248.doc 17-