1239048 玖、發明說明： t發明所屬之技術領域3 發明領域 本發明，係關於半導體裝置之製造方法，特別，關於 5 具有含氮之閘絕緣膜的半導體裝置之製造方法。 I：先前技術3 發明背景 為了提高半導體積體電路之積體度，及動作速度，而 將MOSFET(金屬半導體場效應電晶體)小型化，及將閘緣膜 10 薄膜化。閘絕緣膜上所形成之閘極，一般而言，由多晶石夕 層，或多晶矽層與矽化物之疊層所形成。多晶矽層，通常， 與源/汲區域同時被離子注入雜質。在表面通道型p通道 MOSFET之閘極。源/汲區極，離子注入有p型離質。 當閘絕緣膜變薄時，離子注入於表面通道型P通道 15 MOSFET之閘極的p型雜質即硼，即穿透閘絕緣膜，而產生 到達通到區域之現象。若硼被注入η型區域即通道區域，則 不只使閾值變動，且使移動度劣化。 導入氮於閘絕緣膜事宜對於抑制硼之穿透有效之事已 為眾所熟知。為了向氧化矽層中導入氮，而在ΝΗ3氣體、 20 NO氣體、Ν20氣體等之氮化性氣體氛圍氣中藉電阻加熱或 燈加熱來加熱矽基板之方法，已為眾所周知。使用氮電漿， 將更高濃度之氮導入於氧化矽膜表面之方法，也已為眾周 知。 當閘絕緣膜一變薄，隧道電流即通流於閘極與通道區 1239048 二古吏?冷漏增加之現象也已為眾所周知。若使用電容 部八 1電谷率絕緣膜，以替代氧化矽之閘絕緣膜（之一 )曰财-面把反轉電容換算财變薄，—面把物理膜 5二旱一抑制閘洩漏電流。氮化氧化矽，一般而言，電容 率门於氧化石夕，所以對於一面抑制反轉電容換算膜厚，一 面把物理―厚變厚也有效。 特開2002-198531號，提案有：藉由遠距電毅氮化處 理將氮¥入於形成在矽基板上之氧化矽的閘絕緣膜，接 著以800 C〜ll〇(TC之溫度，在n2〇氛圍氣中將閘絕緣膜氧 1〇化乳化退火，藉此使氮再分佈，形成具有均一氮濃度之閘 絕緣膜事。且揭露一種形成6扣％以上，例如8at%、1〇at%之 均一氮濃度的閘絕緣膜，藉此得以獲取長壽命、高可靠性 之電晶體。 在此’所謂遠距電漿氮化係指，在與收容有基板之處 15理室不同之另外電漿產生室内，藉微波等來產生氮電漿， 將活性氮搬運至處理室來進行氮化之處理而言。 若用N20氛圍氣來進行退火，則可考慮到N20氣體之一 部分分解成N2、02、NO等，從而在控制氧化膜厚增加量、 氮濃度增加量之晶圓面内之均一性，晶圓間之均一性方 20 面，可能產生問題。 特開2002-110674號，更提案有：由於氮一進入Si基板 側之界面附近，MOST(MOS Transister :金氧半導體電晶體） 之移動度即降低，所以為了抑制以基板界面附近之氮濃 度’及減低閘泡漏電流’而導入許多乳事且。就是提案有： 1239048 化預鼠之矽乳氮化臈’進行使用氮氣體之自由基氮 ，猎此抑制從表面擴散之氮流動，並抑制向石夕基板界面 附近之氮之導入量，藉以提高膜表面之氮濃度事宜。 【明内容-j 發明概要 本毛月之目的，係在於提供一種具有薄閉絕緣膜，且 有優點特性之MOSFET的半導難置之製造方法。、 本發明之其他目的係在於，提供一種可抑制離子注入 於閘極之硼之閘絕緣膜穿透，且，抑制通道區域之移動度 10降低的半導體裝置之製造方法。 又 依據本發明之第一觀點，提供半導體之製造方法，其 包含有： Μ 閘絕緣層形成工程，係在半導體基板之活性區域上， 形成閘絕緣層； 15 11導人卫程’係藉*活性氮從上述閘絕緣層表面側導 入氣，及1239048 (ii) Description of the invention: t Technical field of the invention 3 Field of the invention The present invention relates to a method for manufacturing a semiconductor device, and more particularly, to a method for manufacturing a semiconductor device having a nitrogen-containing gate insulating film. I: Prior Art 3 Background of the Invention In order to improve the integration of the semiconductor integrated circuit and the operating speed, the MOSFET (Metal Semiconductor Field Effect Transistor) is miniaturized and the gate film 10 is thinned. The gate formed on the gate insulating film is generally formed by a polycrystalline silicon layer or a stack of a polycrystalline silicon layer and a silicide. Polycrystalline silicon layers are typically ion-implanted with impurities simultaneously with the source / drain regions. Gate of surface channel type p-channel MOSFET. Source / drain region, p-type ion implantation. When the gate insulating film becomes thin, the p-type impurity, which is ion implanted into the gate of the surface channel type P-channel 15 MOSFET, is boron, that is, it penetrates the gate insulating film and reaches the pass-through region. When boron is injected into the n-type region, that is, the channel region, not only the threshold value is changed, but the mobility is also deteriorated. It is well known that introducing nitrogen into the gate insulating film is effective in suppressing the penetration of boron. In order to introduce nitrogen into a silicon oxide layer, a method of heating a silicon substrate by resistance heating or lamp heating in a nitrogenous gas atmosphere such as NH 3 gas, 20 NO gas, and N20 gas is well known. It is also known to use a nitrogen plasma to introduce a higher concentration of nitrogen on the surface of the silicon oxide film. As the gate insulation film becomes thinner, the tunnel current flows through the gate and channel area. 1239048 Ergu? The phenomenon of increased cold leakage is also well known. If the capacitor part is used to replace the insulating film of the silicon gate insulation film (one), the thin film will be converted into a thin film by converting the reverse capacitor to the thin film, and the physical film 5 will be used to reduce the gate leakage current. . Generally speaking, silicon nitride oxide has a permittivity gate that is similar to that of oxidized silica. Therefore, it is also effective to increase the physical-thickness while suppressing the inverse capacitance conversion film thickness. Japanese Patent Application Laid-Open No. 2002-198531 proposes that nitrogen be charged into a gate insulating film of silicon oxide formed on a silicon substrate by a long-distance electro-nitriding process, and then at a temperature of 800 ° C to 110 ° C in The gate insulation film is oxygenated and emulsified in an atmosphere of n20 to oxidize and emulsify the oxygen, thereby redistributing nitrogen to form a gate insulation film having a uniform nitrogen concentration. Also disclosed is a formation of more than 6%, such as 8at%, 10at The gate insulation film with a uniform nitrogen concentration of% can obtain a long-life, high-reliability transistor. Here, the so-called remote plasma nitridation means that it is different from the 15 chambers where the substrate is stored. In the plasma generation chamber, microwave plasma is used to generate nitrogen plasma, and the active nitrogen is transported to the processing chamber for nitridation. If N20 atmosphere is used for annealing, a part of N20 gas can be considered to be decomposed into N2. , 02, NO, etc., in order to control the uniformity of the increase in the thickness of the oxide film and the increase in the concentration of nitrogen, the uniformity between the wafers and the uniformity among the wafers may be problematic. JP 2002-110674, more The proposals are: as nitrogen enters near the interface on the Si substrate side, MO ST (MOS Transister: metal oxide semiconductor transistor) mobility is reduced, so in order to suppress the concentration of nitrogen near the substrate interface 'and reduce the leakage current leakage' many problems. The proposals are: 1239048 pre-mouse The silicon emulsion samarium nitride 'uses free radical nitrogen of nitrogen gas to suppress the flow of nitrogen diffused from the surface, and to suppress the amount of nitrogen introduced near the interface of the Shixi substrate, so as to increase the nitrogen concentration on the film surface.明 内容 -j SUMMARY OF THE INVENTION The purpose of this month is to provide a method for manufacturing a semi-conducting MOSFET which has a thin closed insulating film and has advantageous characteristics. Another object of the present invention is to provide a method capable of suppressing A method for manufacturing a semiconductor device in which a gate insulating film of ion-implanted boron penetrates and suppresses a decrease in the mobility 10 of a channel region. According to a first aspect of the present invention, a method for manufacturing a semiconductor is provided, including: Μ Gate insulation layer forming process is to form the gate insulation layer on the active area of the semiconductor substrate; Induction gas is introduced into the surface of the insulation layer, and
退火處理工程，係在NO氣體氛圍氣中施行退火處理， 以便在導入有氮之閘絕緣層内，在表面側保持氮之高濃度 分佈’並在同半導體基板之界面保持低濃度分佈。 X 20圖式簡單說明 第1A〜1F圖為斷面圖及圖表，係用來說明本發明者所 進行之實驗及其結果。 第2A〜2D圖為斷面圖及圖表，係用來說明本發明者所 進行之實驗及其結果。 1239048 第从、36圖為表及 實驗之條件及結果。 圖表’係顯示本發明所進行的其他 圖為表及圖表，係顯示本發明者所、仓^ 其他實驗之條件及結果。 Μ進行的更 5 10 15 第5Α〜5D圖為半導體基板之斷面圖， 本發明實施例之半導财置之製造方法。Μ明依據 他實娜侧麵進行的其 第 7A、7B、7 距電漿氮 示使用高 、7C圖為斷面圖，係概略地顯示遠 化表置’去她·電漿裝置之構成，及概略地顯 K材料之閘絕緣層之構成。 較佳實施例之詳細說明 若把氮導入於氧化石夕膜，則在對於閘極之石朋之離子注 入時’可有效地防止爛之閘絕緣獻穿透。然而，隨著間 絕緣膜之變L成難⑽止狀穿透，導朗達至閘 絕緣膜與絲板之界面。m彳達料區域，即令移動 度降低。又，界面中之硼濃度易成為不均等。 將由電漿所產生之活性氮導入於氧化石夕膜或氧化氮化 石夕膜二藉此可取得絕_表面及财具有峰值之氮濃度分 佈:藉著使用此種電漿氮化，一面抑制與基板之界面中的 氮/辰度面可導人更多之氮。高氮濃度可有效地抑制石朋 之穿透。 又，導入更多之氮’藉此可把絕緣膜之電容率弄大， 20 1239048 一面把反轉電谷換鼻厚（Teff)壓薄，一面使物理性膜厚徵 更，藉此可有效地抑制閘之漏電流。 將絕緣膜與矽基板之界面中之氮濃度壓低，藉此可抑 制通道區域中之移動度之降低。又，可有效地抑制 5 NBTI(negative bias temperature instability :負偏壓溫度不穩 定性)特性之劣化。又，NBTI特性為加大應力使溫度上升時 之劣化特性。 使氮電漿產生於自基板離開之場所並導入活性氮於基 板之技術，叫做對基板不添加損傷之表面無損傷製程。 10 本發明者認為：儘管將電漿中所產生之活性氮導入於 一從電漿隔開配置之矽基板的絕緣膜，恐也有可能對於基 板添加某種之損傷。為了恢復此損傷而在比氮導入工程更 冋之溫度中退火處理必有效。於是調查了由退火處理所造 成之影響。 15 第1A〜1E圖為斷面圖，係顯示由本發明者所進行的實 驗之樣品製作工程。 、 第ία圖所示’在碎基板1之表面形成用來覆蓋活性區 域4之遮罩，並對矽基板1進行各向異性蝕刻，形成元件分 離用溝2。堆積氧化矽等之絕緣層，以填補元件分離用溝2， 20藉化學機械研磨(CMP)來除去秒基板丨表面上之無用的絕緣 層，藉此形成一藉淺溝隔離膜（ST1)而成之元件分離區域 3其中，該淺溝隔離膜(ST1)係埋入絕緣膜於溝内而成者。 如第1B圖所示，在965°C之氧氛圍氣中，將厚度丨^此㈤ 之氧化膜5形成於矽基板1之活性區域4表面。 1239048 如第1C圖所示，從用1.5W微波來激勵之氮電漿導出活 性氮，利用此活性氮，在45〇°C之氛圍氣中將氮導入於間絕 緣膜5。氮被導入於氧化膜表面後，成為氮化氧化石夕膜5χ。 使用遠距電漿氮化裝置來導入之活性氮’此遠距電货氮化 5裝置可從美國加州聖大克拉（甘 > 夕夕予予）阿布雷特馬特 二 里阿爾公司7。今彳社)取得。 第7Α圖，係顯示遠距電漿氮化裝置之概略構成。將Ν2 、 氣體導入電漿產生室21，使之產生氮電漿。從氮電製產生 活性氮（自由基），供給反應室22内。在反應室2中，備有一 隹 10 含有多數燈之燈加熱裝置23，可加熱晶圓24。 如第1D圖所示，在105(TC之氮氛圍氣中進行退火處 理’使因活性氮之導人而產生之基板之損傷恢復。氮化& 化矽膜5x，即在退火處理下成為氮化氧化矽膜外。 如第1E圖所示，在閘絕緣膜上，藉CVD來堆積厚度 15剛⑽之多晶石夕層，並使用保護層圖案來圖案形成_以 _g)’藉此形成了問長〇.5_〜1〇_左右之閉極6。間 絕緣膜5y也被圖案形成後，成為閉絕緣膜& 籲 、待把間極形成圖案之後，離子注入p型雜質（即B)，形 成了擴展區域7。其後，藉由化學氣相堆積(CvD)將厚度大 .· 2〇約⑼⑽之氧切卿胁絲上，叹覆錢極，接著進 - 盯反應性離子钱刻’以除去平坦面上之氧化石夕膜，只在間 極壁上留下側壁隔片8。 側壁隔片8形成後，進一步， 一曲 ^ ^ 離子庄入p型雜質B，形成 了高漠度源/縣域9。在離子注人H也對於閘極6離 10 1239048 子注入P型雜質B。其後，形成層間絕緣膜，接著，形成用 來露出源/汲區域，閘極之開口，以形成電極。藉此取得了 樣品S1。 又，為了比較而在第1c圖所示之活性氮導入工程之 5後，不進行第1D圖所示之退火處理，如第1£圖所示，製作 了形成有MOSFET之比較樣品S2。 第11?圖為圖案，係顯示所製作之二種MOSFET之特 性。圖+，橫轴係以單位V表示從閘電壓Vq減去閾值雜之 Vq-Vth。縱軸係以單位1113><11111表示將反轉電容換算膜Teff 10乘於相互電導Gm後，再乘積通道區域之寬w與長度L之比 W/L的規格化相互電導。相互電導不管閘絕緣膜之厚度及 通道區均之大小為何，均被規格化。 活性氮導入後，在氮氛圍氣中以1050°C之溫度進行退 火處理之樣品S1之特性si，係表示一種與未進行氮氛圍氣 15中之退火處理的S2之特性S2比較，在大致全區域有更高之 相互電導。這是很清楚地顯示M0SFET之特性在退火處理 下提高。此可認為其結果提高了載體之移動度及提高了飽 和電流。 如此進行後，雖判明了活性氮之導入後藉著進行退火 20處理，而提高電晶體之特性事宜，但進一步調查了特性之 提南依退火處理之條件而如何變化事宜。作為退火處理之 氛圍氣用者，使用了氮(N2)、一氧化氮(NO)、氧(〇2)。 首先，藉由與第1A圖所示之工程同樣之工程，在矽基 板形成了元件分離區域3。接著，藉由與第1B圖所示之工程 1239048 同樣之工程，在溫度965。(：之〇2氛圍氣中將矽基板熱氧化形 成了厚度1.2麵之閘氧化膜5。 其後，以基本溫度550°C進行了與第1€圖所示之工程同 樣之氮化工程，在導入氮之階段，閘絕緣膜之膜厚，係在 借助橢圓儀之測定下，為1.457nm。 如第2A圖所示，對於第三樣㈣，在導人氮後之氮氛 圍氣中進行了 1G5G C之退火處理。此退火處理為不活性氣 體中之退火處理。 10 15 20 如第2BSI所示，祕第四樣品S4，在導人氮後之氮姜 圍氣中進彳T了 95GC之退火處理。此退火處理，係伴隨著秦 化之退火處理者。其後，減錢氣切行了丨⑽。 處理。在此階段’用橢圓儀來測定之問絕緣膜之膜厚3 1.538nm。與第三樣品相較，發現對第四樣品追加有刪 之退火處理。在N0中因退火處理而增加之膜厚為〇顧腿 如第2C圖所示，對於第五樣品％，在氮導入後之 氛圍氣中進行了刚代之退火處理。此退火處理，_ 耆氧化之退域S者。錢，在域 、a 夕π丨名 t 闲礼T運仃了 1050〇C k、处理。/、第二樣品相較，發現對第五樣品追力◦ 中之退火處理。 口有 又，各退火處理，係藉快速熱退火RTA來進彳-α 極端之時間。其後形成了與第―、第二樣品:’ ^ 極、源/汲區域。 ，的絕緣深 第2D圖為圖表，係顯示所製作之第三、第 品之特性。橫軸及縱軸係與第1F_—。四及第五梢The annealing process is performed in a NO gas atmosphere to maintain a high concentration distribution of nitrogen 'on the surface side in the gate insulation layer introduced with nitrogen and a low concentration distribution at the interface with the semiconductor substrate. Brief description of X 20 diagrams Figures 1A to 1F are sectional views and diagrams, which are used to explain the experiments and results of the inventors. Figures 2A to 2D are sectional views and diagrams, and are used to explain the experiments performed by the inventors and their results. 1239048 Figures 36 and 36 show the conditions and results of the table and experiments. The chart 'shows other experiments performed by the present invention. The tables and tables show the conditions and results of other experiments conducted by the inventor. 5-10 15 and 5D to 5D are cross-sectional views of a semiconductor substrate, and a method for manufacturing a semiconductive device according to an embodiment of the present invention. M Ming's 7A, 7B, and 7-pitch plasma nitrogen shows high usage based on Tasna's side. Figure 7C is a cross-sectional view, which schematically shows the structure of the remote surface setting 'go to her plasma device'. And roughly shows the composition of the gate insulation layer of K material. Detailed description of the preferred embodiment If nitrogen is introduced into the oxidized stone film, it can effectively prevent the rotten gate insulation from penetrating when the ion of the gate electrode is injected. However, with the change of the interlayer insulating film, it becomes difficult to stop and penetrate, leading Ronda to the interface between the gate insulating film and the wire plate. If the material area is reached, the mobility will be reduced. In addition, the boron concentration at the interface tends to be uneven. The active nitrogen generated by the plasma is introduced into the oxidized stone film or oxidized nitride film to obtain a nitrogen concentration distribution with a peak on the surface and property: by using this kind of plasma nitriding, the The nitrogen / centre surface in the interface of the substrate can lead more nitrogen. High nitrogen concentration can effectively inhibit the penetration of Shi Peng. In addition, by introducing more nitrogen, the permittivity of the insulating film can be increased. 20 1239048 While reducing the inverse electric valley for the thickness of the nose (Teff), thinning the physical film thickness can effectively increase the physical film thickness. The ground suppresses the leakage current of the brake. By reducing the nitrogen concentration in the interface between the insulating film and the silicon substrate, the decrease in the mobility in the channel region can be suppressed. In addition, degradation of 5 NBTI (negative bias temperature instability) characteristics can be effectively suppressed. The NBTI characteristic is a degradation characteristic when the temperature is increased by increasing the stress. The technique of generating nitrogen plasma at a place away from the substrate and introducing active nitrogen to the substrate is called a non-damaging surface process without adding damage to the substrate. 10 The present inventor believes that although the active nitrogen generated in the plasma is introduced into an insulating film of a silicon substrate arranged apart from the plasma, there is a possibility that some damage may be added to the substrate. In order to recover this damage, the annealing treatment must be effective at a temperature higher than that of the nitrogen introduction process. The influence caused by the annealing treatment was investigated. 15 Figures 1A to 1E are cross-sectional views showing a sample preparation process performed by the inventors. As shown in FIG. 1a, a mask for covering the active region 4 is formed on the surface of the broken substrate 1, and the silicon substrate 1 is anisotropically etched to form a trench 2 for element separation. Stacking insulating layers such as silicon oxide to fill the trenches for element separation 2, 20 Uses chemical mechanical polishing (CMP) to remove unwanted insulating layers on the surface of the second substrate 丨 thereby forming a shallow trench isolation film (ST1) In the element isolation region 3, the shallow trench isolation film (ST1) is formed by embedding an insulating film in the trench. As shown in FIG. 1B, in an oxygen atmosphere at 965 ° C., an oxide film 5 having a thickness of ㈤ is formed on the surface of the active region 4 of the silicon substrate 1. 1239048 As shown in Fig. 1C, active nitrogen is derived from a nitrogen plasma excited with a 1.5W microwave, and the active nitrogen is used to introduce nitrogen into the insulating film 5 in an atmosphere of 45 ° C. After nitrogen is introduced on the surface of the oxide film, it becomes a nitrided oxide stone film 5x. Activated nitrogen introduced using a long-range plasma nitriding device ’This long-range electric cargo nitriding device 5 can be obtained from Santa Clara, California (Gan > Xi Xiyou), Abret Matt II, Rial Company 7, California. Imabari Corporation). Fig. 7A shows a schematic configuration of a remote plasma nitriding device. N 2 and gas are introduced into the plasma generating chamber 21 to generate nitrogen plasma. Active nitrogen (free radicals) is generated from the nitrogen power supply and supplied to the reaction chamber 22. The reaction chamber 2 is provided with a lamp heating device 23 including a plurality of lamps, which can heat the wafer 24. As shown in FIG. 1D, annealing treatment in a nitrogen atmosphere of 105 ° C is used to restore the damage to the substrate caused by the introduction of active nitrogen. Nitriding & siliconized film 5x, that is, under annealing treatment, becomes As shown in Figure 1E, a polycrystalline silicon layer with a thickness of 15 angstroms is deposited on the gate insulating film by CVD as shown in FIG. 1E, and a protective layer pattern is used to form a pattern _ 以 _g) ' This forms a closed pole 6 with a length of about 0.5_ ~ 10_. After the intermediate insulating film 5y is also patterned, it becomes a closed insulating film. After the intermediate electrode is patterned, a p-type impurity (ie, B) is ion-implanted to form an extended region 7. After that, the thickness was increased by chemical vapor deposition (CvD) on a wire of about 20 Å to about 2,000 Å, and the coin was sighed, and then the reactive ion money was engraved to remove the ions on a flat surface. The oxidized stone membrane leaves only the side wall spacers 8 on the interpolar wall. After the sidewall spacer 8 is formed, further, a ^ ^ ion penetrates into the p-type impurity B, and a high desert source / county region 9 is formed. The ion implantation H also implants a P-type impurity B for the gate 6 ion 10 1239048. Thereafter, an interlayer insulating film is formed, and then, an opening is formed to expose the source / drain region and the gate electrode to form an electrode. Thereby, a sample S1 was obtained. For comparison, after the active nitrogen introduction process shown in Fig. 1c, the annealing process shown in Fig. 1D was not performed. As shown in Fig. 1, a comparative sample S2 was formed with MOSFETs. Figure 11? Is a pattern showing the characteristics of the two MOSFETs. In Figure +, the horizontal axis represents the unit V minus the threshold voltage Vq-Vth from the gate voltage Vq. The vertical axis represents the normalized mutual conductance by multiplying the inverse capacitance conversion film Teff 10 by the mutual conductance Gm, and then multiplying the ratio of the width w to the length L of the channel region W / L by the unit 1113>. The mutual conductance is standardized regardless of the thickness of the gate insulating film and the size of the channel area. After the introduction of active nitrogen, the characteristic si of the sample S1 annealed in a nitrogen atmosphere at a temperature of 1050 ° C represents a characteristic S2 that is substantially different from that of the S2 that has not been annealed in a nitrogen atmosphere 15 Regions have higher mutual conductance. This clearly shows that the characteristics of the MOSFET are improved by the annealing treatment. This can be considered as a result of improving the carrier mobility and increasing the saturation current. After doing so, although it was identified that the characteristics of the transistor were improved by annealing 20 after the introduction of the active nitrogen, how the characteristics of Tinam changed according to the conditions of the annealing treatment was further investigated. As the atmosphere user for the annealing treatment, nitrogen (N2), nitric oxide (NO), and oxygen (02) were used. First, by the same process as the process shown in FIG. 1A, an element isolation region 3 is formed on a silicon substrate. Then, by the same process as the process 1239048 shown in FIG. 1B, the temperature is 965. (: The silicon substrate was thermally oxidized to form a gate oxide film 5 with a thickness of 1.2 in a 02 atmosphere. Thereafter, a nitriding process similar to the process shown in Fig. 1 was performed at a basic temperature of 550 ° C. At the stage of introducing nitrogen, the film thickness of the gate insulating film was 1.457 nm as measured by an ellipsometry. As shown in FIG. 2A, for the third sample, the nitrogen was conducted in a nitrogen atmosphere after introducing nitrogen. The annealing treatment of 1G5G C. This annealing treatment is an annealing treatment in an inert gas. 10 15 20 As shown in the second BSI, the fourth sample S4 is immersed in nitrogen nitrogen gas after introducing nitrogen into the gas. 95GC Annealing treatment. This annealing treatment is accompanied by Qin Hua's annealing treatment. After that, the money was cut and cut. ⑽ Treatment. At this stage, the thickness of the insulating film was measured using an ellipsometer 3 1.538 nm. Compared with the third sample, it was found that the annealing annealing was added to the fourth sample. The film thickness increased due to the annealing treatment in NO was 0. As shown in Figure 2C, for the fifth sample, After the introduction of nitrogen, the annealing process has been performed in the atmosphere. This annealing process, _ 耆 oxidation Those who have left the domain S. The money, in the domain, the name t, and the leisure time T ran 1050 ° C, processing./ Compared with the second sample, it was found that the fifth sample was annealed in the chase force. There are various annealing treatments, which are performed by the rapid thermal annealing RTA to enter the 彳 -α extreme time. After that, the first and second samples are formed: '^ pole, source / drain region. The 2D figure is a chart showing the characteristics of the third and third products. The horizontal and vertical axes are the same as the first 1_. The fourth and fifth pins
12 1239048 與*第-樣品在閘絕緣膜之厚度、活性氣導入時之 方面有右干差異之第三樣品S3之特性S3，係 ^ ㈣大致相同。活性氮導人後在舶氛圍氣中钟了 5 10 :二:化)退火處理之樣㈣之特性S4，係顯示明顯 之k南。活性氮導人後在氧氛圍氣中進行了觀t之後 退火處理之樣品SkS5，係顯科者之中間特性。12 1239048 The characteristic S3 of the third sample S3, which has a right-dried difference with respect to the thickness of the gate insulating film and the introduction of the reactive gas, of the * -sample is approximately the same. The active nitrogen was introduced in the atmosphere of the ship for 5 10: 2: chemical). The characteristics of the annealing treatment, S4, showed a significant kN. The sample SkS5, which was annealed after the active nitrogen was introduced in an oxygen atmosphere, was an intermediate characteristic of the subjects.
歸納此等之結果，清楚地顯示活性氮導入後進行退火 處理的話相互電導即提高。儘管在氧氛圍氣中進行退火處 理，與⑽H氣巾之退火處理之情況比較起來相互導電會 提高’但進-步在N(m圍氣中之氮化氧化退火進行時為二 互導電變為最高。 攻疋因為發明者認為，若依N0氛圍氣中之退火，基板 側之界面附近有則效地形成;g夕一氧一氮(Si_〇_N)結合。Summarizing these results, it is clearly shown that the mutual conductance increases when the annealing treatment is performed after the introduction of active nitrogen. Although the annealing treatment is performed in an oxygen atmosphere, the mutual conductivity will be improved compared with the annealing treatment of the ⑽H air towel. The highest attack is because the inventor believes that if annealing is performed in a N0 atmosphere, the vicinity of the interface on the substrate side is effectively formed; g-oxygen-nitrogen (Si_〇_N) bonding.
但，在氧化性或氮化氧化性氛圍氣中之退火處理，可 15使其產生基板之變化，或氮化氧化，使閘絕緣膜變厚。若 作有效閘絕緣膜厚2nm以下之電晶體時，膜厚增加少iN〇 氣圍氣中之退火處理應較為適宜。由No氣體氛圍氣中之退 火處理所達成之絕緣膜之增加，宜為〇 2nm以下。若要取得 厚度1.7nm以下之閘絕緣膜時，初始氧化膜宜作成1.511111以 20 下。 如在習知技術所述，已提案有在矽氧氮化膜導入活性 氮（自由基）。本發明者，係在具有由下述二種製造方法所形 成之絕緣膜之半導體裝置中，進行了可靠性汗估即 TDDB(time dependent dielectric breakdown)之測定。（1)，(2)之 13 1239048 製造方法杉V、丁、氧化膜厚、活性氮導入、NO熱處理、 N2處理，雖說輪流次序有所不同，但各處理内容卻為同一者。 (1) 待形成了熱氧化膜後，用NO氣體氛圍氣加以熱處 理，然後藉活性氮來導入氮，接著，用N2氣體氛圍氣來熱 5 處理之間絕緣膜；及 (2) 待形成了熱氧化膜後，用活性炭來導入氮，然後在 NO氣體氛圍氣中熱處理，進而用比其更高溫之N2氣體氛圍 氣來進行熱處理之閘絕緣膜。 當以上述測定來比較應力外加後在判定基準以下之成 10 品率時，（1)之樣品雖為0%，但(2)之樣品卻為88%，兩者產 生了大差距。 即，（2)之樣品，具有與（1)之樣品大致同樣之在絕緣膜 中之氮分佈，但在可靠性方面之效果之差距卻很大。本發 明者認為此理由為··在活性氮導入處理後進行之NO氛圍氣 15 之熱處理下，在基板側之界面附近高效率地形成矽-氧-氮 (Si-Ο-Ν)結合。 又，在NO氛圍氣中之退火後，其所以進行了更高溫之 N2氣體氛圍氣之熱處理，是為了改善NBTI特性而做者，並 非必須之工程。 20 就電漿氮化裝置來說，除了遠距電漿裝置以外，已知 可從同一美國加州聖大克拉（寸 > 夕夕兮今）阿布雷特馬特 里阿爾公司7°今彳卜^于小只社)取得之去耦RF氮 電漿裝置。 第7B圖，係概略地顯示去耦RF氮電漿裝置之構成。在 14 1239048 此裝置方面，藉由設在反應室25頂部上之線圈26之RF激 勵，使氮電漿產生，其中反應室25係在下部收容樣品27。 氮電漿只在沿著反應室之上壁的，離樣品27之區域内產 生。以下，將此裝置略稱為DPN。 5 使用DPN氮化裝置，形成二種之樣品。 第3A圖，係顯示二種類之樣品S6、S7及比較用之樣品 S8之製作條件。 首先藉由與第ΙΑ、1B圖所示工程同樣之工程，在900 °C之氧氛圍氣中，使用燈退火裝置來成膜一厚度〇8511111之 10氧化矽膜。其後，在DPN裝置内用RF電力700W來激勵氮電 装’接著在室溫氛圍氣中將活性氮導入於一配置在下方之 基板之氧化碎膜。 對於第六樣品S6 ’待在l〇〇〇°C之減壓氧氛圍氣中進行 氧化退火處理(RTO)之後，在l〇5〇°C之氮氛圍氣中進行了退 15 火處理(RTA)。 對於第七樣品S7，活性氮導入後在95〇°C之NO氣體氛 圍氣中進行了氮化氧化退火處理(RTN〇)，接著，在1〇5〇它 之氮氛圍氣中進行了退火處理(RTA)。為了比較，而只用氧 化矽膜來形成閘極之樣品S8，也製作了二類。 2〇 第3B圖，係顯示此等樣品之測定結果。橫軸係以單位 nm表示反轉電容換算膜厚丁6汙。縱軸係以單位(A/cm2)表示 閘漏電流iq。只用氧化矽膜來形成閘絕緣膜之樣品S8之特性 S8，係用X符號表示的2點；外插時便成為直線。 第6樣品S6之特性S6，係位於比較樣品8之特性別之 15 1239048 τ，顯示可減少閘漏電流。 第七樣品S7之測定點S7，為NO中之氮化氧化退火處 理’其氧化被抑制，比測定點S6還薄。又，比特性S8更存 在於下方’顯示與樣品86同樣可減低閘漏電流。 5 於第3B圖之特性，閘漏電流之減低程度係就兩個樣品 S6、S7來說大致同等。樣品8，係將有效閘絕緣膜厚作成 O.OHnm之薄厚。又，具有優異之相互電導。就半導體之特 性來說’在閘長度40nm之MOS電震體方面可提高飽和電流 3.6%。 10 再者，藉由二次離子質量分析(SIMS)，調查了在導入 有活生氮之閘絕緣膜之氮如何分佈之問題。使用DPN作為 活性氮導入裝置，在氧氛圍氣中，及NO氛圍氣中進行了活 性氮導入後之退火處理。 第4A圖之表，係顯示二種類之樣品之製作工程。第九 15樣品S9，係在900 °C氧氛圍氣中藉由燈退火裝置將厚度 0.8〇11之氧化矽膜成膜，然後利用700W之去耦RF氮電漿在 室溫氛圍氣中導入(DPN)活性氮於閘氧化膜中。其後，在 1000 ◦之減壓氧氛圍氣中進行退火處理(RTO)，接著在1〇50 °C之氮氛圍氣中進行退火處理(RTA)。 20 第十樣品S10，係與第九樣品S9同樣形成厚度〇.8nm之 氧化矽膜，藉由DPN裝置導入活性氮之後，進行950°CiNO 氣體氛圍氣中之退火處理，進而在1050°C之氮氛圍氣中進 行了退火處理(RTA)。 第4B圖為圖表，係顯示此等二種類之樣品之測定結 16 1239048 果。橫軸係以單位麵表示距自表面之深度；縱軸係以單位 (at_/ee)麵所測定錢濃度。在氧錢氣巾進行退火處 理之樣品之特性S9，係在表面附近具有更高之♦值，與深 度同時逐地減少氮濃度。雖在敎範目㈣利位數以上之 5氮/辰度之變化，但中途却存在閘絕緣膜與矽基板之界面。 氮化氧化膜之膜厚為1.324nm ;氮濃度之峰值為 8.6at%，與基板之界面中的氮濃度為3·6扣％。在界面之氮 》辰度為峰氣7辰度之1/2以下。 活性氮導入後在NO氛圍中進行退火處理之樣品sl〇之 10特性S10為：其表面側之峰值擴大成某程度之平坦，但由活 性氮之導入而成之氧分佈與由NO氛圍氣中之退火而起之 氮分佈必被含在裡面。其後顯示比特S9高一點之氮濃度， 同時隨深度而減少之趨向，更顯示從某深度之位置形成與 特性S9同樣之分佈。 15 氮化乳化膜之膜厚為M74nm ;氮濃度之峰值為 7.6at% ;與基板之界面中之氮濃度為4.9at%。若使氮化氧化 膜之厚度增加’則可將基板界面之氮濃度作成峰氮濃度之 1/2以下。基板與界面之氮濃度，均為5 at%。 從把表面側之氮濃度作成更高，及把跟基板之界面之 20 氮濃度作成更低之觀點著眼時，〇2等之氧化性氛圍氣中之 退火較為合適。但膜厚之增加卻是大於在氧化氛圍氣中退 火時之增加。從把氮化氧化膜之厚度壓薄，及形成具有優 異驅動力之電晶體的觀點論之’ N0等之氮化氧化性氛圍氣 中之退火較為合適。 17 1239048 不管那-測定結果’氮濃度均在閑絕緣膜表面側 峰值，隨深度而向同矽基板之界面持續減少。因此，可/知· 可將多量之氮導人於閘絕緣膜中，可有效地抑制石朋之外 透，同時與矽基板之界面之氯濃度宜抑制至5at%以下。牙 5 制通道區域中移動度之降低。 ^ 再者，期待僅在氧化矽膜之表面附近導入有活性氮， 以將去耦RF電漿之激勳能從700W降下至500W之條件進/一 了實驗 第6A圖之表，係概略地顯示三種類之製作工程。第十 10 一之樣品811，係在90〇C之氧氛圍氣中，藉由燈退火妒置 將厚度〇.8nm之氧化矽膜加以成膜，利用5〇〇w之去輕奸氮 電漿在室溫氛圍氣中’在沒有偏壓電場下將活性氮導入於 閘氧化膜中（DPN)。其後在10〇〇°C之減壓氧氛圍氣中進行退 火處理(RTO)，進而在1050°C之氮氛圍氣中進行退火處理 15 (RTA) 〇 第十二之樣品S12，係第十一之樣品同樣，在9〇〇。(：氧 氛圍氣中’藉由燈退火裝置將厚度〇.8nm之氧化石夕膜加以成 膜，利用500W之去耦RF氮電漿在室溫氛圍氣中將活性氮導 入於閘氧化膜中（DPN)。其後，在950°C之減壓NO氛圍氣中 20進行了退火處理(RTNO)，進而在i〇5〇°C之氮氛圍氣中進行 了退火處理(RTA)。 第十三之樣品S13 ’係與第十一之樣品同樣，在9〇〇。〇 氧氛圍氣中，藉由燈退火裝置將厚度〇.8nm之氧化矽膜加以 成膜，利用500W之去耦RF，RF氮電漿在室溫氛圍氣中將 1239048 活性氮導入於閘氧化膜中（DPN)。其後，在1〇〇〇t：之減壓氧 氛圍氣中進行退火處理(RTO)，進而在95(rc之減壓N〇氛圍 氣中進行退火處理(RTNO)，接著在咖“氮氛圍氣中進 行了退火處理(RAT)。在NO氛圍氣中之退火處理後，其所 以用高溫進行RTA者，是為了 NBTI特性之改性之改善，並 非為必須之工程。 第6B圖，係顯示二種類之樣品之測定結果。橫軸係表 示距自表面之μ，以單位nm表示；縱轴係、以單位(at〇m/cc) 表示所測定的氮濃度。 10 純氛圍氣中進行了退火處理之第十-樣品SU之特 性S1卜係表面附近具有更高之峰值，炭濃度即隨著深度漸 漸地減少。在測定範圍内表示i位數以上之氮濃度變化。閉 絕緣膜與石夕基板之界面係在存於中途。 氣化氧化膜之膜厚為U89nm，氮濃度之峰值為 15 7.5at%;與基板之界面中之氮濃度為2 2心。在界面之氮 濃度為峰氮濃度的1/2以下。 活欧氮導人後’在NQ氛®氣巾進行退火處理之第十二 樣品S12之特性S12，係在表面附近之峰值增加了一些，並 擴大。其後，雖顯示比特性811高_點之氮濃度中，顯示了 隨深度減少之趨向，但接近界面日魏量便增加，顯示在表 面與界面附近表面具有兩個峰之特徵性之分佈。NO氛圍氣 中之社處理’似乎傾向於將氮導人於與基板之界面附近。 氮化氧化膜之膜厚為U70nm ;氮濃度之峰值為 7.8at% ;與基板之界面中之氮濃度為4 8 —。 20 1239048 活性氮導入後，繼氧氛圍氣之退火來進行NO氛圍氣退 火之第十二樣品S13之特性S13，其表面側之♦值係與氧退 火之樣品之S13之特性S13同等。雖看起來與su之特性有差 距，但這是二次離子質量分析（SIMS)之測定誤差内之羞 5異。從而可確認；如接近界面氮量即增加，界面在no氛園 氣中有效地被氮化。 氮化氧化膜之膜厚為1.157nm;氮濃度之峰值為7.4 at% ;與基板之界面中之氮濃度為2.4 at%。 儘管活性氮導入後，在N0氛圍氣中進行退火處理，以 10改善特性，但在與基板之界面之氮濃度可抑制在5以％以 下。選擇條件，藉此可將在界面之氮濃度作成在表面之氮 濃度之1/2以下。從樣品S12、S13之特性S12、S13，分別控 制氮分佈及借助NO氛圍氣中進行退火處理之氮分佈，藉此 判明可實現各種氮分佈。可在不太變形藉由活性氮導入之 15分佈形狀下，藉N〇氛圍氣中退火將氮導入於界面附近。也 容易實現依在閘絕緣膜表面與基板之界面不同之請求而不 同之氮濃度。 第5A〜5D圖為根據以上之實驗結果的斷面圖，顯示依 據本發明實施例之製造方法。 20 如第5A圖所示，藉ST1將元件分離區域3形成於矽基板 1。在ST1之元件分離區域所劃定之活性區域中，進行所需 之離子注入，形成η型阱4η、p型阱4p。又，雖只顯示了兩 個阱，但同時可形成多數個胖。 在露出之矽基板表面進行8〇〇。〇之熱解法氧化（ργ〇 20 1239048 genic—吵形成厚度7nm之氧切助。該熱解法氧 化為在乳中错由使氫燃燒之氛圍氣來進行氧化之方法。严 度7nm之閉氧化膜，便成為用來製作動作電壓3V左右: MOSFET(金氧半導體場效應電晶體)之閘絕緣膜。 5 ㈣作絲進行低電壓動作之MOSFET之活性區域方 面’藉蚀刻來除所成長的氧化石夕膜n。在赋之氧氛圍氣 中進行乾氧化，形成厚度h2nm之氧化賴12。厚度i — 之閘氧化膜，例如，成為用來製作動作電壓Η 2v左右之 MOSFET之_緣膜。又，若切基板表面存在自然氧化 10膜時’在氫自由基等之還原性氛圍氣除去自然氧化膜也 可。猎著氧化清淨之石夕表面，而可形成良質之氧化石夕膜。 雖說明了形成具有二種厚度之閘絕緣膜的情況，但形 成三種以上之厚度的閘絕緣層也可。 在此氧化下，先前形成之厚氧化矽膜u也成長若干。 15而具有薄閘絕緣膜12之阱，也形成η型及p型。 如第5圖所不，利用由L5kw之微波所得之RpN氮電 忒，在550 C之氛圍氣中將活性氮導入於閘絕緣膜丨丨、12。 導入活性氮，使閘絕緣膜成為氮化氧化矽膜11χ、12χ。 如第5C圖所示，在950°C之NO氣體氛圍氣中進行退火 20處理。藉由N〇氣體進一步將閘絕緣膜氧氮化，使損傷恢 復。像這樣進行之後，形成閘絕緣膜丨0、12y。接著，為 了抑制NBTI特性之劣化，而在氮氛圍氣中進一步進行高溫 之退火處理也可。 其後，在閘絕緣膜上形成lOOnm之多晶矽層，使用保 21 1239048 護層圖案，來圖案形成為所需之間長。在薄閘絕緣膜12y上 形成間長40nm之閘極。 如第5D圖所示，將用來選擇施有圖案形成之間極及n 通道區域，Ρ通道區域的保護層遮罩作為遮罩，進行㈣雜 5質、Ρ聽質之離子注人，⑽作舰Μ7ρ、7η。其後， 堆積厚度大約60nm之氧化錢，進行咖，藉此形成側壁 ^片8 °使用用來分離閘極(具有側壁隔片）及n通道區域、p 通道區域之保護層遮罩，將η型雜質、ρ型雜質離子注入， 形成源/汲區域9η、9ρ。 10 錢’在依需要而露出之％表面，進行_化物化，藉 層間絕賴來覆蓋。然後，在層間絕緣膜2形賴口，形成 引出插頭，進而形成必需要之布線、層間絕緣膜。 如此進行之後，具有薄開絕緣層及厚間絕緣層，在薄 閘絕緣層也抑制狀穿透’ I，形成已抑制通道區域之移 15 動度之降低的CMOS積體電路。 在此工程下，形成-種具有2nnm下，特別丨7邮以下 之薄有效閘絕緣膜厚，可防止石朋之穿透，且可抑制通道區 域之移動度減低之半導體裝置。 像运樣，若依據上述之實施例，則可在問絕緣膜中導 20入表面側較高，在與石夕基板之界面較低之氮濃度，抑制蝴 之閘絕緣膜穿透，且抑制通道區域中之移動度減低。 雖依據以上之實施例說明本發明，但本發明並不限定 於此等實施例。例如，隨目的，而使用用不活性氣體稀釋 之NO中之退火，以替代NO中之氮化氧化退火也可。作為 22 1239048 形成於半導體基板上之絕緣膜用者，可形成含有3at%以下 之氮的^匕氧化石夕膜，以替代氧化石夕膜也可。在氮化氧化 矽膜上疊層具有高電容率之高^^才料之膜也可。 第7C圖，係顯示疊層有high_k(高電容率)材料之膜的構 5成。出灿士材料具有顯著地大於氧化矽之電容率。例如，於 矽基板30表面，在75(rc之氧氛圍氣中藉燈退火裝置來成膜 厚度〇.58nm之氧化矽膜31，並藉由500W之去耦RF氮電漿在 室溫氛圍氣中將活性氮導入於閘氧化膜中（DPN)。其後，進 行900 C之NO氣體氛圍氣中之退火處理(RTN〇)，進而進行 1〇 了 1〇50°C氮氛圍氣中之退火處理(RTA)。此氮化氧化膜厚為 〇_80nm。在底子氧化膜厚，電漿氮化強度、N〇氣體退火溫 度’時間等之調整下，進一步薄膜化應該也可能。在此氧 化氮化臈上，形成A1、Hf、Zr等之氧化膜，該等之氧化石夕 酸鹽膜等high-k(高電容率），藉此防止半導體基板與高電容 15率材料之反應，且，可提供優異可靠性及驅動能力之閘絕 緣膜。 可其他各種之變更、修飾、組合，對該業而言，是顯 而易知者。 產業上之可利用性 0 Λ 適合於特別微細化之MOS電晶體。 式簡單說明】 第1Α〜1F圖為斷面圖及圖表，係用來說明本發明者所 進行之實驗及其結果。 第2A〜2D圖為斷面圖及圖表，係用來說明本發明者所 23 1239048 進行之實驗及其結果。 第3A、3B圖為表及圖表，係顯示本發明所進行的其他 實驗之條件及結果。 第4A、4B圖為表及圖表，係顯示本發明者所進行的更 5 其他實驗之條件及結果。 第5A〜5D圖為半導體基板之斷面圖，係用來說明依據 本發明實施例之半導體裝置之製造方法。 第6A、6B圖為表及圖表，係顯示本發明者所進行的其 他實驗之條件及結果。 10 第7A、7B、7C圖為斷面圖，係概略地顯示遠距電漿氮 化裝置，去耦RF氮電漿裝置之構成，及概略地顯示使用高 K材料之閘絕緣層之構成。 【圓式之主要元件代表符號表】 5x，5y，l lx，12x…氮化氧化石夕膜 6...閘極 5y···閘絕緣膜 5z...閘絕緣膜 1.. .砍基板 2…溝 3.. .元件分離區域 4.. .活性區域 4η·..η型拼 4ρ…ρ型阱 5.. .閘氧化膜 6.. .閘極 7.. .擴展區域 7ρ，7η.·_擴展區域 8.. .側壁隔片 9.. .源/汲區域 9η，9ρ...源/汲區域 11，12…閘絕緣膜 lly···閘絕緣膜 12y···閘絕緣膜 Ig...閘漏電流 S1_S10...樣品 24 1239048However, annealing treatment in an oxidizing or nitriding oxidizing atmosphere can cause a change in the substrate, or nitriding oxidation, to make the gate insulating film thicker. If it is used as a transistor with an effective gate insulation film thickness of 2nm or less, the annealing in iN0 gas should be more suitable if the film thickness is increased. The increase in the insulation film achieved by the annealing treatment in a No gas atmosphere is preferably 0 2 nm or less. To obtain a gate insulation film with a thickness of 1.7nm or less, the initial oxide film should be made 1.511111 or less. As described in the conventional technology, it has been proposed to introduce an active nitrogen (free radical) into a silicon oxynitride film. The present inventors performed a measurement of time dependent dielectric breakdown (TDDB), which is a reliability sweat estimate, in a semiconductor device having an insulating film formed by the following two manufacturing methods. (1), (2) of 13 1239048 Manufacturing method Cedar V, Ding, oxide film thickness, active nitrogen introduction, NO heat treatment, N2 treatment, although the order of rotation is different, each treatment content is the same. (1) After the thermal oxide film is formed, heat treatment with NO gas atmosphere, then introduce nitrogen by active nitrogen, and then heat the interlayer insulation film with N2 gas atmosphere; and (2) to be formed After thermally oxidizing the film, activated carbon is used to introduce nitrogen, and then heat treatment is performed in a NO gas atmosphere, and then a higher temperature N2 gas atmosphere is used to perform the heat treatment of the gate insulation film. When the above measurement is used to compare the 10% yield below the judgment standard after the stress is applied, the sample of (1) is 0%, but the sample of (2) is 88%, which results in a large gap. That is, the sample of (2) has a nitrogen distribution in the insulating film that is approximately the same as that of the sample of (1), but there is a large difference in the effect of reliability. The inventors believe that the reason is that, under the heat treatment of NO atmosphere 15 performed after the active nitrogen introduction treatment, a silicon-oxygen-nitrogen (Si-O-N) bond is efficiently formed near the substrate-side interface. In addition, after annealing in a NO atmosphere, the heat treatment in a higher temperature N2 atmosphere was performed in order to improve the characteristics of NBTI, and it is not a necessary process. 20 As far as plasma nitridation devices, in addition to remote plasma devices, it is known that they can be obtained from the same Santa Clara, California (Inch > Xi Xi Xi Jin) Abret Material 7 ° ^ Yu Xiaoshesha) decoupling RF nitrogen plasma device. Fig. 7B is a schematic diagram showing the structure of a decoupling RF nitrogen plasma device. With respect to this device 14 1239048, a nitrogen plasma is generated by RF excitation of a coil 26 provided on the top of the reaction chamber 25, wherein the reaction chamber 25 houses a sample 27 in the lower part. Nitrogen plasma was generated only in the area along the upper wall of the reaction chamber, away from sample 27. Hereinafter, this device is referred to as a DPN. 5 Use a DPN nitriding device to form two samples. Fig. 3A shows the production conditions of two types of samples S6, S7 and comparison sample S8. First, through the same process as that shown in Figs. 1A and 1B, a lamp annealing device was used to form a silicon oxide film with a thickness of 8511111 in an oxygen atmosphere at 900 ° C. After that, the nitrogen device was excited with 700 W of RF power in the DPN device, and then the active nitrogen was introduced into an oxidized shatter film of a substrate disposed below in a room temperature atmosphere. After the sixth sample S6 ′ was subjected to oxidation annealing treatment (RTO) in a reduced pressure oxygen atmosphere at 1000 ° C, an annealing treatment (RTA) was performed in a nitrogen atmosphere at 105 ° C. ). For the seventh sample S7, after the introduction of active nitrogen, a nitriding oxidation annealing process (RTN0) was performed in a NO gas atmosphere at 95 ° C, and then an annealing treatment was performed in a nitrogen atmosphere of 1050 ° C. (RTA). For comparison, sample S8, which uses only a silicon oxide film to form the gate electrode, has also been made into two types. 2 Figure 3B shows the measurement results of these samples. The horizontal axis is expressed in units of nm. The vertical axis represents the leakage current iq in units (A / cm2). The characteristics of the sample S8, which uses only a silicon oxide film to form the gate insulation film, S8, are 2 points represented by the X symbol; when extrapolated, it becomes a straight line. The characteristic S6 of the sixth sample S6, which is located at 15 1239048 τ of the specific gender of the comparative sample 8, shows that the gate leakage current can be reduced. The measurement point S7 of the seventh sample S7 is a nitriding oxidation annealing treatment in NO, and its oxidation is suppressed, which is thinner than the measurement point S6. Furthermore, it is more important than the characteristic S8 in the lower portion 'that shows that the gate leakage current can be reduced as in the case of the sample 86. 5 In the characteristics of Fig. 3B, the reduction degree of the gate leakage current is about the same for the two samples S6 and S7. Sample No. 8 was obtained by making the effective gate insulation film thickness as thin as O.OHnm. In addition, it has excellent mutual conductance. In terms of the characteristics of the semiconductor, the MOS electro-oscillator with a gate length of 40 nm can increase the saturation current by 3.6%. 10 Furthermore, the secondary ion mass analysis (SIMS) was used to investigate the distribution of nitrogen when a gate insulating film with live nitrogen was introduced. DPN was used as the active nitrogen introduction device, and annealing was performed after the introduction of active nitrogen in an oxygen atmosphere and a NO atmosphere. The table in Figure 4A shows the production process of two types of samples. The ninth 15 sample S9 was formed into a silicon oxide film with a thickness of 0.810 by a lamp annealing device in an oxygen atmosphere at 900 ° C, and then introduced into a room temperature atmosphere using a 700W decoupling RF nitrogen plasma ( DPN) active nitrogen in the gate oxide film. Thereafter, annealing treatment (RTO) was performed in a reduced-pressure oxygen atmosphere at 1,000 ° C, and then annealing treatment (RTA) was performed in a nitrogen atmosphere at 1050 ° C. 20 The tenth sample S10 is the same as the ninth sample S9. A silicon oxide film with a thickness of 0.8 nm is formed. After introducing active nitrogen through a DPN device, annealing is performed in a 950 ° C iNO gas atmosphere, and then at 1050 ° C. Annealing (RTA) was performed in a nitrogen atmosphere. Figure 4B is a graph showing the results of these two types of samples. The horizontal axis represents the depth from the surface in unit planes; the vertical axis represents the concentration of money measured in unit (at_ / ee) planes. The characteristic S9 of the samples which were annealed in the oxygen purse is that it has a higher value near the surface and reduces the nitrogen concentration one by one at the same time as the depth. Although there is a change of 5 nitrogen / degree above the profit margin, there is an interface between the gate insulating film and the silicon substrate. The thickness of the nitrided oxide film is 1.324 nm; the peak of the nitrogen concentration is 8.6 at%, and the nitrogen concentration at the interface with the substrate is 3.6%. The nitrogen at the interface is less than 1/2 of 7 degrees of peak gas. The characteristic S10 of the sample sl10 which is annealed in the NO atmosphere after the introduction of active nitrogen is: the peak on the surface side expands to a certain level, but the distribution of oxygen resulting from the introduction of active nitrogen and the distribution in the NO atmosphere The nitrogen distribution resulting from the annealing must be contained in it. It then shows that the nitrogen concentration of bit S9 is a little higher, and at the same time, it decreases with depth, and it also shows that the same distribution as characteristic S9 is formed from a certain depth position. 15 The film thickness of the nitrided emulsified film is M74nm; the peak of the nitrogen concentration is 7.6at%; the nitrogen concentration in the interface with the substrate is 4.9at%. If the thickness of the nitrided oxide film is increased ', the nitrogen concentration at the substrate interface can be made 1/2 or less of the peak nitrogen concentration. The substrate and interface nitrogen concentrations were both 5 at%. From the viewpoint of making the nitrogen concentration on the front side higher and the nitrogen concentration on the interface with the substrate lower, the annealing in an oxidizing atmosphere such as O2 is more suitable. However, the increase in film thickness is greater than that during annealing in an oxidizing atmosphere. From the viewpoint of reducing the thickness of the nitrided oxide film and forming a transistor having an excellent driving force, annealing in a nitriding oxidizing atmosphere such as 'N0' is more suitable. 17 1239048 Regardless of the measurement result, the nitrogen concentration peaks at the surface of the insulating film, and decreases with the depth toward the interface with the silicon substrate. Therefore, it can be known that a large amount of nitrogen can be introduced into the gate insulation film, which can effectively suppress the penetrating of the stone. At the same time, the chlorine concentration at the interface with the silicon substrate should be suppressed to 5at% or less. Decreased mobility in dental 5-channel area. ^ Furthermore, it is expected that active nitrogen will be introduced only near the surface of the silicon oxide film to reduce the excitation of the decoupling RF plasma from 700W to 500W. The table in Figure 6A of the experiment is outlined. Three types of production processes are displayed. The sample 811 of the eleventh one is in a 90 ° C oxygen atmosphere, and a silicon oxide film having a thickness of 0.8 nm is formed by lamp annealing, and a nitrogen plasma is used to lightly rape the plasma by 500,000 w. Active nitrogen is introduced into the gate oxide film (DPN) in a room temperature atmosphere without a bias electric field. Thereafter, annealing treatment (RTO) was performed in a reduced-pressure oxygen atmosphere at 100 ° C, and then annealing treatment was performed in a nitrogen atmosphere at 1050 ° C. 15 (RTA). Sample 12 of the twelfth is the tenth One of the samples was the same at 900. (: In an oxygen atmosphere ', an oxide oxide film with a thickness of 0.8 nm is formed by a lamp annealing device, and a 500 W decoupling RF nitrogen plasma is used to introduce active nitrogen into the gate oxide film in a room temperature atmosphere. (DPN). Thereafter, an annealing treatment (RTNO) was performed in a reduced-pressure NO atmosphere at 950 ° C and then an annealing treatment (RTA) was performed in a nitrogen atmosphere at 105 ° C. Tenth The third sample S13 ′ is the same as the eleventh sample. In a 90 ° oxygen atmosphere, a silicon oxide film with a thickness of 0.8 nm is formed by a lamp annealing device, and a 500W decoupling RF is used. The RF nitrogen plasma introduced 1239048 active nitrogen into the gate oxide film (DPN) in a room temperature atmosphere. Thereafter, it was annealed (RTO) in a reduced pressure oxygen atmosphere at 1000 t: 95 (RTNO in a reduced-pressure NO atmosphere, followed by annealing treatment (RAT) in a nitrogen atmosphere. After annealing in a NO atmosphere, it was subjected to RTA at high temperature. This is to improve the characteristics of NBTI, and it is not a necessary process. Figure 6B shows the measurement of two types of samples Results. The horizontal axis represents μ from the surface and is expressed in units of nm. The vertical axis represents the measured nitrogen concentration in units (at0m / cc). 10 The tenth-annealed in a pure atmosphere The characteristic S1 of the sample SU has a higher peak near the surface, and the carbon concentration gradually decreases with the depth. In the measurement range, the nitrogen concentration changes above the i-bit number. The interface between the closed insulating film and the Shixi substrate is at The thickness of the gasification oxide film is U89nm, and the peak nitrogen concentration is 15 7.5at%; the nitrogen concentration at the interface with the substrate is 2 2 cores. The nitrogen concentration at the interface is 1/2 of the peak nitrogen concentration. The characteristics of the twelfth sample S12, which is annealed in the NQ atmosphere® air towel after the introduction of live Euro nitrogen, are S12. The peak near the surface has increased and expanded. After that, it shows higher than characteristic 811 The nitrogen concentration in the _ point shows a trend that decreases with depth, but the amount of Japanese Wei near the interface increases, showing a characteristic distribution of two peaks on the surface and the surface near the interface. The social treatment in the NO atmosphere seems to tend Attach nitrogen to the interface with the substrate The film thickness of the nitrided oxide film is U70nm; the peak of the nitrogen concentration is 7.8at%; the nitrogen concentration in the interface with the substrate is 4 8-. 20 1239048 After the introduction of active nitrogen, annealing is performed after the annealing with oxygen The characteristic S13 of the twelfth sample S13 in the atmospheric annealing is the same as the characteristic S13 of the S13 in the oxygen-annealed sample. Although it looks different from the characteristic of su, this is a secondary ion mass analysis (SIMS) measurement error within 5 different. It can be confirmed; if the amount of nitrogen near the interface increases, the interface is effectively nitrided in the no atmosphere garden gas. The thickness of the nitrided oxide film is 1.157 nm; the peak of the nitrogen concentration is 7.4 at%; the nitrogen concentration in the interface with the substrate is 2.4 at%. After the introduction of active nitrogen, annealing is performed in a N0 atmosphere to improve the characteristics, but the nitrogen concentration at the interface with the substrate can be suppressed to 5% or less. By selecting conditions, the nitrogen concentration at the interface can be made less than 1/2 of the nitrogen concentration on the surface. From the characteristics S12 and S13 of the samples S12 and S13, the nitrogen distribution was controlled and the nitrogen distribution subjected to the annealing treatment in the NO atmosphere was used to determine that various nitrogen distributions could be achieved. The nitrogen can be introduced near the interface by annealing in a NO atmosphere under a shape of 15 distribution that is not deformed by the introduction of active nitrogen. It is also easy to achieve different nitrogen concentrations depending on the requirements of the interface between the gate insulation film surface and the substrate. Figures 5A to 5D are cross-sectional views based on the above experimental results, showing a manufacturing method according to an embodiment of the present invention. 20 As shown in FIG. 5A, the element isolation region 3 is formed on the silicon substrate 1 by ST1. In the active region defined by the element isolation region of ST1, a desired ion implantation is performed to form an n-type well 4n and a p-type well 4p. Also, although only two wells are shown, a large number of fats can be formed at the same time. The exposure was performed on the exposed surface of the silicon substrate. 〇oxidation by pyrolysis (ργ〇20 1239048 genic—formation of oxygen with a thickness of 7nm. The pyrolysis oxidation is a method of oxidizing the milk by the atmosphere that causes hydrogen to burn. The 7nm closed oxide film It becomes a gate insulating film used to make an operating voltage of about 3V: MOSFET (metal oxide semiconductor field effect transistor). 5 The active area of the MOSFET that operates as a low-voltage operation is to remove the grown oxide by etching. Even film n. Dry oxidation in an oxygen-doped atmosphere to form an oxide film with a thickness of h2nm. A gate oxide film with a thickness of i — for example, is used to make a MOSFET edge film with an operating voltage of about 2v. If there is a natural oxide film on the surface of the cut substrate, the natural oxide film can be removed in a reducing atmosphere such as hydrogen radicals. The surface of the stone oxide can be hunted to oxidize and clean, and a good oxide film can be formed. It is possible to form a gate insulating film with two thicknesses, but it is also possible to form a gate insulating layer with three or more thicknesses. Under this oxidation, the previously formed thick silicon oxide film u also grows a little. 15 and a thin gate The wells of the edge film 12 also form η-type and p-type. As shown in Fig. 5, the active nitrogen is introduced into the gate insulating film in an atmosphere of 550 C by using the RpN nitrogen voltage obtained from the microwave of L5kw. , 12. Introduce active nitrogen to make the gate insulation film into silicon nitride oxide films 11x, 12x. As shown in Fig. 5C, annealing 20 is performed in a NO gas atmosphere at 950 ° C. The nitrogen gas is further used to The gate insulating film is oxynitrided to restore damage. After this, the gate insulating film is formed, and 0, 12y are formed. Next, in order to suppress the deterioration of the NBTI characteristics, a high temperature annealing treatment may be performed in a nitrogen atmosphere. After that, a polycrystalline silicon layer of 100 nm is formed on the gate insulating film, and the pattern is formed to a desired length using a protective layer pattern of 122139048. A gate electrode with a length of 40 nm is formed on the thin gate insulating film 12y. As shown in FIG. 5D As shown in the figure, the protective layer mask used to select the region between the patterned electrodes and the n-channel region and the p-channel region is used as a mask to implant the dopants of dopant 5 and p-aperture. 7η. After that, oxidized money with a thickness of about 60nm was deposited, and In order to form a side wall 8 °, a protective layer mask for separating the gate electrode (with a side wall spacer) and the n-channel region and the p-channel region is used to implant n-type impurities and p-type impurities into the source / drain. Areas 9η and 9ρ. 10% of the surface is exposed as needed, and is chemically covered by the interlayer insulation. Then, the interlayer insulation film is formed into a two-dimensional opening to form a pull-out plug, and then a necessary cloth is formed. Wire and interlayer insulation film. After doing this, it has a thin open insulation layer and a thick interlayer insulation layer, and the thin gate insulation layer is also inhibited from penetrating 'I, forming a CMOS integrated body that has suppressed the movement of the channel area and reduced the 15 degree of dynamics. Circuit. Under this project, a semiconductor device with a thin effective gate insulation film thickness of 2nnm, especially below 7nm, can be prevented from penetrating, and can reduce the mobility of the channel area. As such, according to the above embodiment, the surface of the insulating film can be higher at the entrance side, and the nitrogen concentration at the interface with the Shixi substrate can be lower, which can prevent the butterfly insulation film from penetrating, and inhibit Reduced mobility in the channel area. Although the present invention has been described based on the above embodiments, the present invention is not limited to these embodiments. For example, depending on the purpose, annealing in NO diluted with an inert gas may be used instead of nitriding oxidation annealing in NO. As a user of an insulating film formed on a semiconductor substrate, it is possible to form a silicon oxide film containing 3at% or less of nitrogen, instead of the oxide film. It is also possible to laminate a film having a high permittivity on the silicon nitride oxide film with a high permittivity. Fig. 7C shows the structure of a film laminated with a high_k (high permittivity) material. Chucan materials have a permittivity that is significantly greater than that of silicon oxide. For example, on the surface of a silicon substrate 30, a silicon oxide film 31 having a thickness of 0.58 nm is formed by a lamp annealing device in an oxygen atmosphere of 75 (rc), and a 500 W decoupled RF nitrogen plasma is used at room temperature. The active nitrogen is introduced into the gate oxide film (DPN), and then an annealing treatment (RTN0) in a NO gas atmosphere at 900 C is performed, and then an annealing in a nitrogen atmosphere at 1050 ° C is performed. Treatment (RTA). The thickness of this nitrided oxide film is 0-80nm. Under the adjustment of substrate oxide film thickness, plasma nitridation strength, NO gas annealing temperature 'time, etc., further thinning should be possible. Oxidation here On hafnium nitride, oxide films such as A1, Hf, and Zr are formed, and high-k (high permittivity) oxides such as oxidized oxalate films are prevented, thereby preventing the semiconductor substrate from reacting with high-capacitance 15-rate materials, and It can provide a gate insulation film with excellent reliability and driving ability. Various other changes, modifications, and combinations are obvious to the industry. Industrial availability 0 Λ is suitable for special miniaturization MOS transistor. Brief description of the formula] Figures 1A to 1F are sectional views and diagrams. The experiments performed by the present inventors and their results are illustrated. Figures 2A to 2D are cross-sectional views and graphs, which are used to illustrate the experiments performed by the inventor 23 1239048 and their results. Figures 3A and 3B are tables and The graphs show the conditions and results of other experiments performed by the present invention. Figures 4A and 4B are tables and graphs, which show the conditions and results of more 5 other experiments performed by the inventor. Figures 5A to 5D are semiconductors. The cross-sectional view of the substrate is used to explain the manufacturing method of the semiconductor device according to the embodiment of the present invention. Figures 6A and 6B are tables and charts showing the conditions and results of other experiments performed by the inventor. 10 Section 7A , 7B, 7C are sectional views, which schematically show the structure of a remote plasma nitriding device, a decoupled RF nitrogen plasma device, and the structure of a gate insulating layer using a high-K material. The main components represent the symbol table] 5x, 5y, l lx, 12x ... Nitride oxide film 6 ... Gate 5y ... Gate insulation film 5z ... Gate insulation film ... Cut the substrate 2 ... Groove 3... Element separation area 4... Active area 4η · ..η type spelling 4ρ… ρ type 5 .. Gate oxide film 6 .. Gate 7. Extension area 7ρ, 7η ·· _ Extension area 8. .. Sidewall spacer 9... Source / Drain area 9η, 9ρ ... Source / Sink area 11, 12 ... Gate insulation film lly ... Gate insulation film 12y ... Gate insulation film Ig ... Gate leakage current S1_S10 ... Sample 24 1239048
Vg…閘電壓 Gm···變換電導Vg ... gate voltage Gm ... converted conductance
Vth...閾值 25Vth ... threshold 25