45 13 37 _— ------— —~—— ----—-------——— ----— 五、發明說明（1) 發明之領域 本發明提供一種去除半導體晶片之蝕刻殘留物的方法 與其設備，尤指一種利用超臨界流體（supercritical liquid)去除半導體晶片之蝕刻殘留物的方法舆其設備。 背景說明 Ο 在目前的蝕刻製程中，多半採用電漿蝕刻的乾蝕刻方 式。然而，電漿的蝕刻事實上是由蝕刻反應舆高分子生成 反應等兩種平行的機制所構成的，也就是說，在進行電漿 蝕刻時，半導體晶片表面也會有蝕刻殘留物（etch residue)的產生。這些蝕刻殘留物多半以高分子 (polymer)的狀態存在，不僅會成為污染或腐蝕的來源， 有時亦會給予元件電器特性不良影響·»因此，在蝕刻製程 之後’通常要在進行一清洗製程來去除高分子或其他蝕刻 殘留物^ Ο 習知蝕刻殘留物的去除方式為使用溶劑（solvent)(例 如Act93 5或EKC27 0等型號的溶劑），將蝕刻殘留物中的大 分子分解後再溶解，以去除蝕刻殘留物。當半導體晶片表 ! 面之接觸洞（contact hole)或介層洞（via hole)的高深比 ；(asPect ratio)太高時’液態溶劑往往無法擴散至接觸洞 或介層洞的深處，造成深處的蝕刻殘留物不易去除，進一 步造成產品的功能失效（function fail)。此外，習知去 除方式需要使用多種溶劑而溶劑價格又十分昂貴，亦為習45 13 37 _-- ---------~ —— -------------------------------- V. Description of the invention (1) Field of the invention The present invention provides a A method and equipment for removing etching residues of semiconductor wafers, especially a method for removing etching residues of semiconductor wafers using a supercritical fluid (supercritical liquid). Background 〇 In the current etching process, plasma etching is mostly used for dry etching. However, plasma etching is actually composed of two parallel mechanisms, such as an etching reaction and a polymer generation reaction, that is, when plasma etching is performed, there will also be etch residues on the surface of the semiconductor wafer. ). Most of these etching residues exist in the state of polymer, which will not only become a source of contamination or corrosion, but also adversely affect the electrical characteristics of the device. "Therefore, after the etching process, it is usually necessary to perform a cleaning process. To remove macromolecules or other etching residues. ^ Conventionally, the way to remove etching residues is to use a solvent (such as Act93 5 or EKC27 0 and other types of solvents). The macromolecules in the etching residue are decomposed and then dissolved. To remove etching residues. When the height ratio of the contact hole or via hole of the semiconductor wafer surface is too high; (asPect ratio) is too high, the liquid solvent often cannot diffuse to the depth of the contact hole or via hole, causing Deep etching residues are not easy to remove, which further causes the product to fail. In addition, the conventional removal method requires the use of multiple solvents, and the solvent is very expensive.
第4頁 451337 五、發明說明（2) 知去除方式的缺點。 發明概述 本發明之主要目的在於提供一種利用超臨界流體去除 半導體晶片之蝕刻殘留物的方法與其設備’以徹底去除半 導體晶片中接觸洞或介層洞深處的蝕刻殘留物。 本發明為一種利用超臨界流體清洗半導體晶片的方 法，係用來去除至少一半導雄晶片表面或縫隙中的蝕刻殘 留物。該方法首先將該半導體晶片置入一清除室内，接著 將一流體通入該清除室内。該清除室之壓力係大於該流體 之臨界壓力，且該清除室之溫度係高於該流艘之臨界溫 度，使該流體成為一氣態與液態共存之超臨界流逋來清洗 該半導體晶片表面。該流體可為二氧化碳、水或氧化亞 氮β該方法可另外將一化學液舆該流饉一起通入該清除室 内，以增加該流體去除該半導體晶片表面之髒污的效果。 本發明另一實施例為一種利用超臨界流體來清洗半導 體晶片的設備，用來清除至少一半導體晶片表面或缝隙中 的蝕刻殘留物。該設備包含有一清除室、至少一供應槽、 一管線、一加熱裝置以及一加壓装置《該清除室與該供應 槽分別用來容納該半導體晶片舆一流體，該管線則用來將 該供應槽内之流體導入該清除室内。該加熱裝置用來使該 清除室内之流體溫度高於該流體之臨界溫度，而該加壓裝Page 4 451337 V. Description of the invention (2) Know the disadvantages of the removal method. SUMMARY OF THE INVENTION The main object of the present invention is to provide a method and an apparatus for removing etching residues of semiconductor wafers by using a supercritical fluid, so as to completely remove etching residues deep in contact holes or via holes in a semiconductor wafer. The present invention is a method for cleaning a semiconductor wafer by using a supercritical fluid, which is used to remove at least half of the etching residue on the surface or gap of the male wafer. The method first places the semiconductor wafer in a cleaning chamber, and then passes a fluid into the cleaning chamber. The pressure of the cleaning chamber is greater than the critical pressure of the fluid, and the temperature of the cleaning chamber is higher than the critical temperature of the flow vessel, so that the fluid becomes a supercritical flow coexisting with gaseous and liquid to clean the surface of the semiconductor wafer. The fluid may be carbon dioxide, water, or nitrous oxide β. The method may additionally pass a chemical liquid into the cleaning chamber together with the flow to increase the effect of the fluid on removing dirt on the surface of the semiconductor wafer. Another embodiment of the present invention is an apparatus for cleaning semiconductor wafers by using a supercritical fluid, for removing etching residues on the surface or gaps of at least one semiconductor wafer. The equipment includes a cleaning chamber, at least one supply tank, a pipeline, a heating device, and a pressurizing device. The cleaning chamber and the supply tank are respectively used to accommodate the semiconductor wafer and a fluid, and the pipeline is used to supply the supply The fluid in the tank is introduced into the cleaning chamber. The heating device is used to make the temperature of the fluid in the cleaning chamber higher than the critical temperature of the fluid, and the pressure device
451337 -----—_ __ 五 '發明說明（3) 置用來，該清除室内之流體壓力高於該流體之臨界壓力。 該清除室内之流骰會形成一氣態與液態共存之超臨界流體 以清洗該半導想晶片表面。該流體可為二氡化碳、水或氧 化^氣。該方法可另外將一化學液與該流體一起通入該清 除室内’以增加該流體去除該半導體晶片表面之辨污的效 果。 〇 本發明的特點在於利用超臨界流體並同時通入該化學 液’來分解並溶解蝕刻後所產生的高分子或其他雜質。對 於具有高深比較大之接觸洞或介層洞的半導髏晶片，會有 較好的清除效果。該化學液可分解蝕刻殘留物中的高分 子’使分解後的高分子容易溶解於超臨界流體而撝出該去 除室之外’而達到清除該半導髖晶片表面髒污的目的。 發明之詳細說明 請參考圈一，圊一為本發明利用超臨界流體來清洗半 導艘晶片之設備10的示意圖β本發明清除設備10是用來清 潔至少一半導親晶片i 2的表面。在本發明中，半導體晶片 12為一完成蝕刻製程的半導體晶片，而清除設備1〇是用來 去除其表面之縫隙（trench)中的#刻殘留物。 清除設備10包含有一清除室（strip chamber) 14用來 放置半導艘晶片12’至少一供應槽16用來容納一流醴18, 以及一管線2 0用來將供應槽16内的流體18導入清除室14451337 -----—_ __ Five 'Explanation (3) is used to set the pressure of the fluid in the cleaning chamber higher than the critical pressure of the fluid. The flow dice in the clearing chamber will form a gaseous and liquid co-existing supercritical fluid to clean the surface of the semiconductor wafer. The fluid may be carbon dioxide, water or oxidized gas. The method can additionally pass a chemical liquid into the cleaning chamber together with the fluid 'to increase the effect of the fluid in removing the stain on the surface of the semiconductor wafer. 〇 The present invention is characterized by using a supercritical fluid and simultaneously passing in the chemical liquid 'to decompose and dissolve polymers or other impurities generated after etching. For semiconducting wafers with contact holes or vias that are relatively high in depth and depth, there will be better removal effects. The chemical liquid can decompose the high molecules in the etching residue, make the decomposed polymers easily dissolve in the supercritical fluid and scoop out the removal chamber ', so as to remove the dirt on the surface of the semiconductor hip chip. Detailed description of the invention Please refer to circle 1, which is a schematic diagram of an apparatus 10 for cleaning semiconductor wafers using a supercritical fluid according to the present invention. Β The cleaning device 10 of the present invention is used to clean at least half of the surface of the guide wafer i 2. In the present invention, the semiconductor wafer 12 is a semiconductor wafer that has been subjected to an etching process, and the removing device 10 is used to remove #nick residues in a trench on the surface thereof. The cleaning device 10 includes a strip chamber 14 for placing semi-conductor wafers 12 ′, at least one supply tank 16 for receiving first-line 醴 18, and a line 20 for introducing the fluid 18 in the supply tank 16 to the cleaning. Room 14
第6頁 451337 五、發明說明（4) 内。清除設備10另包含有一加熱裝置（未顯示）與一加壓裝 置’分別用來使清除室U内的流體溫度與流體壓力高於流 艘18的臨界溫度（critical temperature，TC)與臨界塵力 (critical pressure, PC)0 本發明利用超臨界流體清洗半導體晶片的方法，首先 丨將半導體晶片12置入清除室14之内，然後再將流體ι8通入 丨清除室14内。由於清除室14的壓力大於流艘18的臨界壓 力’而且清除室14的溫度高於流體18的臨界溫度，使流效 I 1 8成為一氣態與液態共存之超臨界流艎，以清洗半導髏晶 片12表面或去除其表面的蝕刻殘留物》 在本發明中，加壓裝置是指在管線20上設置一幫浦 (pump) 22’用來對供應槽16内的流艘18加壓，並將流髋 1 8輸入到清除室1 4之内。加熱裝置則可利用加熱線圏或電 阻絲等等加熱逋，透過直流或交流電流來加熱。清除室14 上另設有一限流閥（restrictor) 24’用來限制超臨界流 饉排出的流量，以維持清除室14内的壓力。清除設備1〇自 半導體晶片12上清除的髒污或殘渣，也可經由限流閥22# 出。 清除設備10所使用的流體18可以是二氧化碳（carbon dioxide，CO2)、水（Η20)或氧化亞氮（nitrous oxide, N20)等等具有可轉化成超臨界狀態的物質。而本發明以使Page 6 451337 V. Description of Invention (4). The cleaning device 10 further includes a heating device (not shown) and a pressurizing device 'to make the temperature and pressure of the fluid in the cleaning chamber U higher than the critical temperature (TC) and the critical dust force of the flow vessel 18, respectively. (critical pressure, PC) 0 In the method for cleaning semiconductor wafers by using a supercritical fluid, the semiconductor wafer 12 is first placed in the cleaning chamber 14, and then the fluid 8 is passed into the cleaning chamber 14. Because the pressure of the cleaning chamber 14 is greater than the critical pressure of the flow vessel 18 and the temperature of the cleaning chamber 14 is higher than the critical temperature of the fluid 18, the flow efficiency I 1 8 becomes a supercritical flow coexisting with gaseous and liquid to clean the semiconducting In the present invention, the pressurizing device refers to a pump 22 ′ provided on the pipeline 20 to pressurize the flow boat 18 in the supply tank 16. The flow hips 18 are entered into the clearing chamber 14. The heating device can use a heating wire 圏 or a resistance wire to heat the 透过 and heat it by DC or AC current. The cleaning chamber 14 is further provided with a restrictor 24 'for limiting the flow rate of the supercritical flow 馑 to maintain the pressure in the cleaning chamber 14. The dirt or residue removed by the cleaning device 10 from the semiconductor wafer 12 can also be discharged through the restrictor valve 22 #. The fluid 18 used in the removal device 10 may be carbon dioxide (CO2), water (Η20), or nitrous oxide (N20), etc., which can be converted into a supercritical state. And this invention makes
第7頁 ；4 51337 ! ' " —^___ _ | 五、發明說明（5) 用二氛化破為k’因為二氧化碳的臨界溫度與臨界壓力 (分別為31. 3t與γ2· 9 atm)較其他物質為低，在實用上十 I分方便’也較不會對半導體晶片12造成損害。除此之外， !使用二氧化碳還具有純度高、價格便宜以及生產量 (throughput)高的優點。 請參考圖二，鬮二為本發明清洗設備1〇之第二實施例 的示意圈β清洗設備10可另外設置一供給裝置26，用來供 應一化學液（modifier) 28，以增加超臨界流髏清洗半導 體晶片12表面的效果β化學液28與超臨界流體將同時通入 清除室1 4内’化學液28會先與蝕刻殘留物或髒污中的高分 子反應’等到高分子分解成較小的分子時，再由超臨界流 體溶解帶出。化學液28的使用量不用太多，其流量控制在 流體1 8流量的1 %〜2¾左右即可。此外，化學液28也可直接 存放於如圈一的供應槽16内，與流體18—起輸入清除室14 之内。 化學液28可以為氨水（ammonia, NH3)或醯胺類化合物 等之胺基（amine based)化合物，也可以是包含聚乙稀 (polyethylene)與鐵氟龍（teflon)的混合溶液（型號 A c 19 3 5 )，或是包含乙醇胺（e t h a η ο 1 a m i n e， H0CH2CH2NH2)、氫氧化胺（Hydroxylamine，NH20H)、異丙醇 胺（Isopropanol amine, CH3CH(OH)CH2NH2)與鄰-苯二紛 (Pyrocatecol，C6H4(〇H)2)的混合溶液（型號 EKC270)。Page 7; 4 51337! '&Quot; — ^ ___ _ | V. Description of the invention (5) Breaking into k by diatomization because of the critical temperature and critical pressure of carbon dioxide (31.3 t and γ 2 · 9 atm, respectively) It is lower than other materials, and it is convenient in practical use. It is also less likely to cause damage to the semiconductor wafer 12. In addition, the use of carbon dioxide has the advantages of high purity, low price, and high throughput. Please refer to FIG. 2, which is a schematic circle of the second embodiment of the cleaning device 10 of the present invention. The β cleaning device 10 may further be provided with a supply device 26 for supplying a modifier 28 to increase the supercritical flow. The effect of skeletal cleaning on the surface of the semiconductor wafer 12 β chemical liquid 28 and supercritical fluid will pass into the cleaning chamber 14 at the same time. 'The chemical liquid 28 will first react with the polymers in the etching residue or dirt' and wait until the polymers decompose into Small molecules are carried out by dissolution of the supercritical fluid. The amount of the chemical liquid 28 need not be too much, and its flow rate can be controlled to about 1% to 2¾ of the flow rate of the fluid 18. In addition, the chemical liquid 28 can also be directly stored in the supply tank 16 such as a circle, and is input into the cleaning chamber 14 together with the fluid 18. The chemical liquid 28 may be an amine based compound such as ammonia (NH3) or ammonium compounds, or may be a mixed solution containing polyethylene and teflon (type A c 19 3 5), or it contains ethanola (etha η ο 1 amine, H0CH2CH2NH2), hydroxylamine (NH20H), isopropanol amine (CH3CH (OH) CH2NH2), and ortho-phenylenediline (Pyrocatecol , C6H4 (〇H) 2) mixed solution (model EKC270).
第8頁 4 5-1 337 五、發明說明（6) Ο 本發月的特點在於利用超臨界流艘並加入化學液28， 來分解並溶解蝕刻後所產生的高分子或其他雜質。超臨界 流體是一種非極性、液態與氣態共存的流體，因此其擴散 速度較液體快，且氣態的流體能深入接觸洞或介層洞深 處。對於具有高深比較大之接觸洞或介層洞的半導體晶 片’會有較好的去除效果。本發明並加入化學液28,藉由 化學液28來分解蝕刻殘留物中的高分子，使分解後的高分 子容易溶解於超臨界流體而攜出去除室14外，進而達到清 除半導艘晶片1 2表面髒污的目的。 相較於習知使用溶劑去除蝕刻殘留物的方式，本發明 利用超臨界流體的清除方式可深入半導體晶片12表面的細 縫中’以確保接觸洞或介層洞深處内的蝕刻殘留物可以完 全去除。本方法並加入化學液28，來分解蝕刻殘留物或高 分子，以加速清洗製程的進行。 以上所述僅本發明之較佳實施例，凡依本發明申請專 利範圍所做之均等變化與修飾，皆應屬本發明專利之涵蓋 範圍》Page 8 4 5-1 337 V. Description of the invention (6) 〇 The feature of this month is to use supercritical flow vessel and add chemical liquid 28 to decompose and dissolve the polymer or other impurities generated after etching. A supercritical fluid is a non-polar, liquid and gaseous coexisting fluid, so its diffusion rate is faster than that of a liquid, and a gaseous fluid can penetrate deep into the cavity or the depth of a cavity. For semiconductor wafers with high depth and large contact holes or via holes, it will have a good removal effect. In the invention, a chemical liquid 28 is added, and the polymer in the etching residue is decomposed by the chemical liquid 28, so that the decomposed polymer is easily dissolved in the supercritical fluid and carried out of the removal chamber 14, thereby achieving the removal of the semiconductor wafer 1 2 The purpose of the surface is dirty. Compared with the conventional method of using solvents to remove etching residues, the present invention utilizes a supercritical fluid removal method to penetrate deep into the fine slits on the surface of the semiconductor wafer 12 to ensure that the etching residues in the depth of the contact hole or via hole can Remove completely. In this method, a chemical solution 28 is added to decompose the etching residues or polymers to accelerate the cleaning process. The above are only the preferred embodiments of the present invention, and all equivalent changes and modifications made in accordance with the scope of the patent application for the present invention shall fall within the scope of the patent of the present invention "
第9頁 451337 圖式簡單說明 圖示之簡單說明 ^ 圖一為本發明利用超臨界流體來清洗半導體晶片之設 備的示意圖。 圖二為本發明清洗設備之第二實施例的示意圖》 圖示之符號說明 10 清除設備 12 半導體晶片 14 清除室 16 供應槽 18 流體 20 管線 22 幫浦 24 限流閥 26 供給裝置 30 化學液Page 9 451337 Brief Description of the Drawings Brief Description of the Drawings ^ Figure 1 is a schematic diagram of a device for cleaning semiconductor wafers using a supercritical fluid according to the present invention. Figure 2 is a schematic diagram of the second embodiment of the cleaning equipment according to the present invention. "Symbols shown in the diagram 10 Cleaning equipment 12 Semiconductor wafer 14 Cleaning chamber 16 Supply tank 18 Fluid 20 Pipe 22 Pump 24 Restriction valve 26 Supply device 30 Chemical liquid
第10頁Page 10