1309854 九、發明說明： 【發明所屬之技術領域】 本發明係種轉體製作方法，_涉及—鱗極氧化法成長閑極氧 化層之方法。 【先前技術】 MOS)電晶體之閘極主要由讀料來製作。然而，隨著積體電路树尺寸不斷 縮小，對閘極氧化層質量要求越來越嚴格，使得關於超薄閘極氧化層製造方法 之研究迅速地發展起來。目前’魏金屬氧化物半導體製造方法主要有快速熱 氧化法(Rapid Th_l Oxidation)、氮摻雜氧化法(顧如⑽妬㈣、液相沈 積法(Liquid Phase Deposition)以及陽極氧化法(牆此以―)等。其中，陽 極氧化法成長之氧化層比其他方法所形成之氧化層具有更高均勻性。 傳統陽極氧化法成長氧化層技術’通常以去離子水或稀酸為電解液，以 pt為陰極，矽晶片為陽極，對矽晶片陽極氧化形成氧化矽層。1998年4月7曰公 告之美國第5,736,454號專利提供一種採用純水陽極氧化法於矽基底上製造二 氧化矽層之方法。該方法包括以下步驟：以矽基底為陽極，在室溫下發生電解 反應’於碎基底上形成二氧化矽層；將矽基底移除電解液；在惰性氣體氛圍， 7〇〇°C〜1000°C溫度下，加熱該基底一段時間，以使二氧化矽層密度增加。請 參閱第一圖，係用於該方法之電解反應系統示意圖。該系統包括一電解槽丄； —程控電源2 ; —程控靜電計3 ;以及監控程控電源2及程控靜電計3之電腦4。 在電解槽1内盛有純水以作電解液5，並有一鉑金屬片作陰極6，一晶片作陽極 1309854 7，其浸入純水電解液5中。電解反應時，電流密度為卜聊~咖2，且以 %AW為佳。該綠形觸極氧化財較少孔騎較佳厚度均勻性。但由 於電解時在純水電解液中電場分佈不均勻，使·氧化層均勻度很難獲得進一 步提高’同時造成閘極氧化層漏電流增加。 2〇m年ίο月11日公告之台灣第_腦58號專利提供一種閘極氧化膜之製 造方法，包括如下步驟：真空中加熱半導體基板，以去除自然氧化膜；通過含 有氧電_離《所產生的氧自氧傾半導體基板；停止供應氧自由基； 然後於氧分子氣氛tit行減理。财法时氧魏解魏财魏化氣氛， 通過控Φ腦能量，來㈣厚度方⑽氧化，啸輒化縛度。而水平方向 的乳化反祕由含氧分子氣氛所進行，並由艇善氧频密度，形成具良好控 制性，小於3咖的超_。惟，該製造方法賴設備娜，操條件嚴苛，並 且電裝氧化難以實現氧倾之細均句性，影響·氧化膜之品質。 有鑑於此，提供-種能成長均勻性更高、漏電流低之問極氧化層之方法實 為必要。 【内容】 為克服先前技術中所形成之閘極氧化層均勻性難以提高，且漏電流較高等 不足，本發敗㈣在於提供-魏絲均更高、漏電流低之閘極氧^ 之方法 為實現上述目的，本個提供-誠長超_極氧化層之方法其包括以 下步驟： 提供一矽晶片； 1309854 將石夕晶片置入電解液中，以1或胳抗 Λ其為％極，並以麵為陰極； 採用直流電疊加一固定頻率交流 閣極氡化t 场極魏形成超薄 而且’所述電解液採用去離子水或稀酸。 所採用電流密度範圍為 所述電源通電過程中保持電流密度恨定， 5〜500μΑΑ:ιη2，且以 10〜5〇MA/cm2 為佳。 所述超薄閘極氧化層之厚度範圍為1奈米〜3奈米。 所述石夕晶片採用P型多晶石夕片。 ”所述細L鮮蝴_直_脈衝電源 豎加電源來實現。 又置机 另，還可進-步對形成之超薄祕氧化層進行熱處理。 與先前技術相比，本發明採用直流疊加交流陽極氧化法成長超薄問極氧化 ’通過娜氧化直峨上編定鮮之_，來爾解液中離子 遷移速率及方向，使電解液中離子獲得重新分佈的機會，從而有效改善電解液 中電^勻分佈現象，最終獲得物更佳、漏電流低之超薄 【實施方式】 a 下面結合附圖對本發明作進一步詳細說明。 h閱第_® ’為用於成長超薄祕氧化層之電解线示賴。該電解系 統10包括f解槽H ’其内盛有電解液12 ; 一陽極; 一陰極14 ;—電源 其可供應整個系統的電源；—靜電發生器16’其提供範圍可調之靜電壓， T 〇〜_ ’並且可提供恆定電壓或財電流密度；以及―交流發生器17，其 k供固定鱗、振刚小之交流電。其中，電解㈣為去離子水或稀酸。 1309854 陽極丄3騎晶片，並根據需要將其全部或部分浸人電解液i2中，而陰㈣ 採用始偏。在觀統ίο中，靜電發生器16與交流發生器η之聯接方 式可採用並聯或串聯方式，給電解槽U同時供電，魅電解反應。電解過程 中，去離子水被離解成與0Η·，然後在電場個下分別遷移至陰陽極，相 應地在始陰極14及硬晶片陽極13上發生如下電極反應： 陰極反應：2Η+ + 2e— = Η2 陽極反應：Si + 40Η' =Si〇2 +2Η20 + 4e· 結果，在石夕晶片上陽極氧化形成多孔二氧化石夕層，即為服氧化細未 示）’因而電解液I2中Off會對閘極氧化層之形成具有較大影響。 結合上述裝置，說明本發明所提供之成長超薄間極氧化層之方法，其包括 以下步驟： ⑴提供，晶片。辦晶片可選自p型多晶外等材質，然後對其進行 拋光處理及減理，絲自魄化層謂得平滑表面，㈣卿猶極氧化處 理。 ⑺卿晶片置人電解液12中，以其為陽極13，並以_陰極μ。本實 施例採用去離子水為電解液12，即將經步驟⑴翁後之梦晶片置入去離子水 中，作為電解反應之陽極13，而陰極14採_金屬片。根據需要，發晶片可 全部或部分浸入去離子水中。 ⑶通電树晶#上陽純化成長超薄祕氧化層。特陽極13與陰 極I4接通魏、，财晶片進行陽極氧化處理，於其表面成長超薄二氧化石夕層。 其中所通之電知用直流電疊加一固定頻率之小振幅交流電。該直流電由靜電 1309854 發生器16供應，而固定頻率之小振幅交流電由交流發生器17供應。由於電流 岔度過问％，會增加氧化瞑之燒毀率，因而，在本發明之電解過程中，電解反 應時保持電流密度蚊，並控制在5〜5⑻_em2之間，且以1()〜5{)^^2為 佳。為實現直流疊加交流電源，採用可控石夕調壓，在直流電源基礎上加脈衝電 源，其通斷比為2 : 1~5 : 1 ;也可採用單相交直流疊加電源，此時，靜電發生 杰16之電壓與交流發生器17之最大振幅電壓之比例範圍可採用m 1。 關於交直流疊加電源請參閱涂益川等人在《電艘與塗飾》，vi9⑺，2_， 13-17，‘‘恆定電流密度下鋁合金的硬質陽極氧化，，一文相關介紹。 另，為提高超薄間極氧化膜層品質及密度，可對其進一步進行熱處理。 通常當閘極氧化層厚度祕3nm時，如果氧化層之均勻性較差，將出現 直接穿遂效應(版Ct Tunneling E細），導致閘極氧化層漏電流增加。而本發 B月成長之_氧化層為超薄氧化層，膜厚在㈡肺。為避免產生上述現象， 必須提昇氧化層之均勻性。因而，本發日咖直流疊加交流陽極氧化法，通過 在陽極氧化時施加的直流電壓上疊加一固定頻率之小振幅交流電。如此以來， 直流電壓和提極氧化_魏量，岭加的小觀技電服供離子重 新分^機會’以形成均勻性更高之超薄閘極氧化層，降低其漏電流。 ^閱第二圖’為本發明之成長超相極氧化層之電解原理示意圖。圖 帙線粗...田表不漏電流大小，橫線越粗表示漏電流越大，反之亦然。當電解反 應發生，在綱壓下’如電壓大於：伏時，與傳統陽極氧化法相同，树陽 極η與陰極14⑽現電場分佈叫現象，造成電解独中電場強弱及 。刀佈也不均勻，目而虱滤離子18遷移速率及方向不均勻，在電場強的 1309854 遷料顿快，奴轉龄向上料輕«，_在相應位置 積水較夕魏根離子1δ，使其氧化加劇，如第三a圖中開極氧化層μ中氧化 :置L1或L2所不。如果持續此靜電壓不變’氧化位置之氧化將繼 •.只加深’軸為漏電流較為射顧。•鼓電«加-小滅交流電後， 電佩小至低於1伏，此時，氧化速率相對下降，電場分佈發生變化’氣氧根 中^8獲取重新分佈機會，使敎氧化程度較弱位置氧化加深，如第三B圖 中閉極航層K氧化位置LMU所示。當然，也有電場影攀極小之位置， 如财魏位置L5所示。通過小振幅交流騎直流電之微調刺，來改變整 固電解液中電場分佈，織_ Μ爾歸㈣會，以彌補氧化 ^之不均勾，最终可獲得厚度及孔洞均勾一致之問極氧化層叫如第^圖所 不）而且’讀均勻性更佳之氧化層體現出低漏電流特性。 因此’在本發觀之成長糊極氧化層之方法卜小振幅之交· ^個電解過程帽簡財軒遷移具有微微應，不斷難離子遷移迷率 及方向，使電解液中離子獲得重新分佈的機會，從而可有效改善電解液中奸 不均勻分佈現象，最終獲得均勾性更佳、低漏電流之間極氧化層。" 綜上所述’本發明符合發明專利之要件，妥触提出專利申請。惟，以 者僅為本發明之較佳實施例，自不能以此限制本案之申請專利範圍。舉 无、，《本案技藝之人士，在援依本案發明精神所作之等效修 匕 含於以下之申請專利範圍内。 ；級匕，白應包 【圖式簡單說明】 第圖係習知成長超薄閘極氧化層之電解系統示意圖。 第二圖係本發明之成長超_極氧化層之電解系統示意圖 1309854 意圖 第三A圖係本發明之成長超_極氧化層 之電解電壓偏焉時電解原理示 意圖 第三_係本發.《超薄_魏層之麵輕偏麟電解原理示 之電解最終結果示意 圖 L1 、L2 ' L3、L4、L5 10 電解槽 11 12 陽極 13 14 電源 15 16 交流發生器 17 18 閘極氧化層 19 第三(：_本發明之成長超_極氧化層 【主要元件符號說明】 氧化位置 電解系統 電解液 陰極 靜電發生器 氫氧根離子 121309854 IX. Description of the invention: [Technical field to which the invention pertains] The present invention relates to a method for producing a swivel body, which relates to a method of growing a oxidized layer by a scale-polar oxidation method. [Prior Art] The gate of the MOS) transistor is mainly made of a read material. However, as the size of the integrated circuit tree continues to shrink, the quality of the gate oxide layer is becoming more and more stringent, and research on the manufacturing method of the ultrathin gate oxide layer has rapidly developed. At present, the 'Wei metal oxide semiconductor manufacturing methods mainly include rapid thermal oxidation (Rapid Th_l Oxidation), nitrogen doping oxidation method (Gu Ru (10) 妒 (4), liquid phase deposition (Liquid Phase Deposition) and anodizing method (the wall ―), etc. Among them, the oxide layer grown by the anodic oxidation method has higher uniformity than the oxide layer formed by other methods. The conventional anodization method for growing the oxide layer 'usually uses deionized water or dilute acid as the electrolyte, to pt The cathode is a cathode, and the tantalum wafer is an anode, and the tantalum wafer is anodized to form a tantalum oxide layer. The method of producing a tantalum dioxide layer on a tantalum substrate by a pure water anodization method is provided in US Pat. No. 5,736,454 The method comprises the steps of: forming an erbium oxide layer on a crushed substrate by using a ruthenium substrate as an anode; forming a ruthenium dioxide layer on the ruthenium substrate; removing the electrolyte from the ruthenium substrate; in an inert gas atmosphere, 7 〇〇 ° C 〜 The substrate is heated for a period of time at a temperature of 1000 ° C to increase the density of the cerium oxide layer. See the first figure, which is a schematic diagram of an electrolytic reaction system used in the method. Including an electrolytic cell 丄; - programmable power supply 2; - programmable electrometer 3; and computer 4 monitoring the programmable power supply 2 and the programmable electrometer 3. The electrolytic cell 1 contains pure water for the electrolyte 5, and has a platinum metal The chip is used as the cathode 6, a wafer is used as the anode 1309554, and it is immersed in the pure water electrolyte 5. When the electrolysis is carried out, the current density is 卜聊~咖2, and it is preferably %AW. The green shape is less oxidized. Hole riding is better in thickness uniformity. However, due to the uneven electric field distribution in the pure water electrolyte during electrolysis, it is difficult to obtain a further improvement in the uniformity of the oxide layer, and at the same time, the leakage current of the gate oxide layer is increased. 2〇m年ίο The Taiwan No. 58 patent issued on the 11th of the month provides a method for manufacturing a gate oxide film, comprising the steps of: heating a semiconductor substrate in a vacuum to remove a natural oxide film; and containing oxygen from the generated oxygen. Oxygen tilting the semiconductor substrate; stopping the supply of oxygen free radicals; then reducing the oxygen in the oxygen molecular atmosphere. When the method is used, the oxygen is used to control the Weiqi Weihua atmosphere, and by controlling the Φ brain energy, (4) the thickness side (10) is oxidized, and the smashing degree is bound. Horizontal direction The anti-mystery is carried out by an oxygen-containing molecular atmosphere, and is formed by a boat with a good oxygen density, which is well controlled, and is less than 3 ga. However, the manufacturing method relies on equipment, harsh conditions, and electrical oxidation. It is difficult to achieve the fine-spokenness of oxygen tilting, affecting the quality of the oxide film. In view of this, it is necessary to provide a method for the higher polarity uniformity and low leakage current of the polar oxide layer. The uniformity of the gate oxide layer formed in the prior art is difficult to increase, and the leakage current is high, etc., and the failure (4) is to provide a method in which a gate electrode having a higher Wistron and a low leakage current is used to achieve the above object. The method for providing a long-lasting super-polar oxide layer comprises the steps of: providing a silicon wafer; 1309854 placing the stone wafer into the electrolyte, using 1 or a yoke as a % pole, and a surface as a cathode Using a direct current to superimpose a fixed frequency, the exchange of the poles, the formation of the field, the formation of ultra-thin and the use of deionized water or dilute acid. The current density range used is such that the current density during the energization of the power source is hatched, 5 to 500 μΑΑ: iπ 2 and preferably 10 to 5 〇 MA/cm 2 . The ultrathin gate oxide layer has a thickness ranging from 1 nm to 3 nm. The Shi Xi wafer adopts a P-type polycrystalline stone tablet. The thin L fresh butterfly _ straight _ pulse power supply vertical power supply to achieve. Another machine, but also step-by-step heat treatment of the formation of ultra-thin secret oxide layer. Compared with the prior art, the present invention uses DC superposition The anodic oxidation method of the ultra-thin polar oxidation method is carried out by the oxidization of the ruthenium, and the ion migration rate and direction in the solution are obtained, so that the ions in the electrolyte are re-distributed, thereby effectively improving the electrolyte. The phenomenon of uniform distribution of the intermediate electricity, the final obtaining is better, and the leakage current is low. [Embodiment] a The present invention will be further described in detail below with reference to the accompanying drawings. h read _® 'is used for growing ultra-thin secret oxide layer The electrolysis system 10 includes an unsolving tank H' containing an electrolyte 12 therein; an anode; a cathode 14; a power source that supplies power to the entire system; and an electrostatic generator 16' providing range Adjustable static voltage, T 〇 〜 _ ' and can provide constant voltage or current density; and "AC generator 17, k for fixed scale, vibration of small alternating current. Among them, electrolysis (four) for deionized water or thin Acid. 13098 54 The anode 丄3 rides on the wafer and immerses all or part of it in the electrolyte i2 as needed, while the negative (4) adopts the initial deviation. In the Guan ί, the connection between the electrostatic generator 16 and the AC generator η can be connected in parallel. Or in series, powering the electrolytic cell U at the same time, the electrolysis reaction. During the electrolysis process, the deionized water is dissociated into 0Η·, and then migrated to the anode and cathode respectively under the electric field, correspondingly at the beginning cathode 14 and the hard wafer anode. The following electrode reaction occurred on 13: Cathodic reaction: 2 Η + + 2e - = Η 2 Anode reaction: Si + 40 Η ' = Si 〇 2 + 2 Η 20 + 4e · As a result, anodization was formed on the Shi Xi wafer to form a porous SiO 2 layer. That is, the oxidization fine is not shown) 'Therefore, the Off in the electrolyte I2 has a great influence on the formation of the gate oxide layer. The method for growing the ultra-thin interlayer oxide layer provided by the present invention is described in combination with the above device, and includes The following steps: (1) Providing, wafer. The wafer can be selected from p-type polycrystalline and other materials, and then polished and reduced. The silk self-deuterated layer is said to have a smooth surface, (4) Qing Jue oxidation treatment. Wafer placement In the electrolyte 12, it is used as the anode 13 and the cathode is used. In this embodiment, deionized water is used as the electrolyte 12, that is, the wafer of the step (1) is placed in deionized water as the anode of the electrolytic reaction. The cathode 14 is _metal piece. If necessary, the wafer can be fully or partially immersed in deionized water. (3) Powered tree crystal #上阳 purified and grown ultra-thin secret oxide layer. Special anode 13 and cathode I4 are connected to Wei, the chip Anodizing treatment is carried out to grow an ultra-thin dioxide layer on the surface thereof. The electric current is superimposed with a fixed-frequency small-amplitude alternating current by a direct current. The direct current is supplied by the electrostatic 1308854 generator 16 and has a small amplitude of a fixed frequency. The alternating current is supplied by the alternating current generator 17. The current enthalpy is excessively increased, which increases the burn rate of the cerium oxide. Therefore, in the electrolysis process of the present invention, the current density is maintained during the electrolysis reaction, and is controlled between 5 and 5 (8)_em2. And 1()~5{)^^2 is preferred. In order to realize the DC superimposed AC power supply, the controllable Shihua voltage regulation is adopted, and the pulse power supply is added on the basis of the DC power supply, and the on-off ratio is 2:1~5:1; the single-phase AC-DC superposition power supply can also be used, at this time, the static electricity The ratio of the voltage of the generator 16 to the maximum amplitude voltage of the AC generator 17 can be m 1 . For the AC-DC superimposed power supply, please refer to Tu Yichuan et al. in "Electric Boat and Finishing", vi9(7), 2_, 13-17, ‘The hard anodization of aluminum alloy under constant current density, a related introduction. Further, in order to improve the quality and density of the ultra-thin interlayer oxide film layer, it may be further subjected to heat treatment. Usually, when the thickness of the gate oxide layer is 3 nm, if the uniformity of the oxide layer is poor, a direct tunneling effect (Ct Tunneling E) will occur, resulting in an increase in leakage current of the gate oxide layer. The growth layer of the B-month of this issue is an ultra-thin oxide layer with a film thickness of (2) lung. In order to avoid the above phenomenon, the uniformity of the oxide layer must be improved. Therefore, the present invention is a superimposed AC anodic oxidation method in which a small amplitude alternating current of a fixed frequency is superimposed on a direct current voltage applied during anodization. In this way, the DC voltage and the ED oxidation _Wei amount, Lingjia's small spectroscopy electric service for the ion re-equalization opportunity to form a more uniform ultra-thin gate oxide layer, reducing its leakage current. ^See the second figure' is a schematic diagram of the electrolysis principle of the growing superphase pole oxide layer of the present invention. Figure 帙 Line is thick... The field surface does not leak current, the thicker the horizontal line, the larger the leakage current, and vice versa. When the electrolytic reaction occurs, when the voltage is greater than: volts, the current electric field distribution of the tree anode η and the cathode 14 (10) is called the phenomenon, which causes the electric field to be strong and weak. The knife cloth is not uniform, and the migration rate and direction of the filter ions 18 are not uniform. In the electric field strength of 1,190,854, the material is quickly moved, the slaves turn to the age and the material is light, and the water in the corresponding position is 1δ, so that the Weigen ion is 1δ. Its oxidation is exacerbated, as in the third a diagram of the open oxide layer μ oxidation: set L1 or L2. If this static voltage is kept constant, the oxidation of the oxidation site will continue to be deeper than the axis. • After the drum is charged and added, the electric pebbles are as small as less than 1 volt. At this time, the oxidation rate is relatively decreased, and the electric field distribution changes. [The oxygenation in the oxygen radicals is 8 to obtain a redistribution opportunity, so that the oxidation degree is weak. The position oxidation is deepened, as shown in the third B diagram of the closed-pole aeronautical layer K oxidation position LMU. Of course, there is also a position where the electric field shadow is extremely small, as shown by the financial position L5. Through the small-amplitude AC riding, the fine-tuning of the DC is used to change the electric field distribution in the solid electrolyte. The weaving _ Μ 归 ( (4) will compensate for the unevenness of the oxidation, and finally the thickness and the hole are consistent. It is called “not shown in the figure” and the oxide layer with better read uniformity exhibits low leakage current characteristics. Therefore, the method of growing the oxidized layer of the paste in the present view is the intersection of the small amplitude. The electrolysis process of the Captain Jane Choi-Yuan has a slight response, and it is difficult to ionize the migration rate and direction, so that the ions in the electrolyte can be redistributed. Therefore, the uneven distribution of the traits in the electrolyte can be effectively improved, and finally a highly oxidized layer with better uniformity and low leakage current is obtained. " In summary, the invention conforms to the requirements of the invention patent and makes a patent application. However, the present invention is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application in this case. For those who have the skills of this case, the equivalent amendments made in the spirit of the invention in this case are included in the scope of the following patent application. ; Grade 匕, 白应包 [Simple description of the diagram] The diagram is a schematic diagram of the electrolysis system of the ultra-thin gate oxide layer. The second figure is a schematic diagram of the electrolysis system of the grown super-polar oxide layer of the present invention. 1309854. It is intended that the third embodiment is a schematic diagram of the electrolysis principle of the electrolysis voltage of the super-polar oxide layer of the present invention. Ultra-thin _ Wei layer of light surface lining electrolysis principle shows the final result of electrolysis L1, L2 'L3, L4, L5 10 electrolytic cell 11 12 anode 13 14 power supply 15 16 AC generator 17 18 gate oxide layer 19 third (: _ the growth of the invention super _ pole oxide layer [main component symbol description] oxidation position electrolysis system electrolyte cathode electrostatic generator hydroxide ion 12