201225176 六、發明說明： 【發明所屬之技術領域】 本發明屬於半導體製造技術領域，具體涉及深孔石夕 (through silicon Via，TSV)刻蝕技術，尤其涉及一種深 孔石夕刻钱中側壁保護層的形成方法。 【先前技術】 半導體製造技術領域中，在Ms201225176 VI. Description of the Invention: [Technical Field] The present invention relates to the field of semiconductor manufacturing technology, and particularly relates to through silicon Via (TSV) etching technology, and more particularly to a deep hole stone etched money side wall protective layer The method of formation. [Prior Art] In the field of semiconductor manufacturing technology, in Ms
(Micro-Electro-Mechanical Systems > 3D 封裝技㈣領域，通常需要_科料進行深通孔刻姓。例 如，在體石夕刻敍技術中，深石夕通孔（Thr〇ugh_SiUc〇n_Via， tsv)的深度達到幾百微米、其深寬比遠大於1〇，通常採用深 反應離子刻蝕方法來刻蝕體矽形成。 圖1所示為現有技術深反應離子刻敍方法示意圖。現有 技術_ ’ TSV的深反應離子刻餘通常採用美國專利US55_3 提出的Bosch工藝進行。如圖i所示，其中，12為_石夕， 11為掩膜層’ 13為聚合物層；掩膜層11通常為Si〇2或者 Si孤，主要在刻蝕過程起掩膜作用。具體深反應離子刻蝕方 法包括以下步驟：⑴聰步驟，通常用Ar、⑶、SFe的混合 氣體進行等離子體刻韻，；⑵聚合物沉積步驟，通常用紅 和C4Fs的混合氣體在孔洞内側面形成氟碳聚合物層，其厚度一 般在納米級，有時也稱作該聚合物層為齡層，為使孔洞底 部基本不形成氟碳聚合物層，該步驟中一般採用相對較低較 的RF (Radio Frequency，射頻）頻率；⑶刻歸驟和聚 合物沉積步驟㈣進行’直到通孔_完成，在難步驟中， 201225176 由於孔洞的内表面、尤其是孔洞内側面沉積聚合物，垂直等 離^•刻辦’人射的離子不會對其_面聚合物造成破壞側 』得X被保，而垂直方向人射的離子會將孔洞底部的聚合 物破壞使.反應得以向下繼續，從而保證了整個孔洞刻飯 過知的各向異性。特別是在彡恤過程中，獅電容轉合等離 子體源（Capacitive Coupled Plasma，CCP)技術，可以加 快在垂直方向的職速度，各向異性特性更好。因此通過以 上所述深反應離子刻倾術職TSV時，具有刻料度快卜 般能達到5-以上）、側麵直度範圍在9㈣度内、 掩膜層與孔洞之間的彭刀（undereut)小於Q.丨_的特點。 近。為了防止織凹坑騎度過大造成下_步處理步驟（如 導體沉積）困難’所以採用傳統BQSch流程的刻財法每個 在刻歸驟中少量氧氣的添加不能在側壁形成足夠的保護層 所以職步驟會在_形成凹坑，紐在下—個聚合物沉^ 步驟中被聚合物保護，每個韻和沉積步驟交替的週期都會 在侧壁形成-個凹坑，多個這種凹坑形成扇形側壁，降低^ 通孔的側壁的光滑度。由於麻擁是等向性的，每個刻兹 步驟都會在儀形成凹坑，·的深度與向下難的深度接 近。為了防止侧劈ω拉沾遝疮通士 ϋ、π ..(Micro-Electro-Mechanical Systems > 3D packaging technology (4) field, usually need to _ science material for deep hole hole surname. For example, in the body stone eve technology, deep stone eve through hole (Thr〇ugh_SiUc〇n_Via, tsv) The depth reaches several hundred micrometers, and its aspect ratio is much larger than 1 〇. The deep reactive ion etching method is usually used to etch the body 。. Figure 1 shows a schematic diagram of the prior art deep reactive ion characterization method. The deep reactive ion engraving of TSV is usually carried out by the Bosch process proposed in US Pat. No. 55_3. As shown in Fig. i, wherein 12 is _石夕, 11 is the mask layer '13 is a polymer layer; the mask layer 11 is usually Si〇2 or Si is isolated, mainly in the etching process as a mask. The specific deep reactive ion etching method includes the following steps: (1) Cong step, usually using a mixture of Ar, (3), SFe for plasma engraving; (2) In the polymer deposition step, a fluorocarbon polymer layer is usually formed on the inner side of the hole by a mixed gas of red and C4Fs, and the thickness thereof is generally on the order of nanometers, sometimes referred to as the layer of the polymer layer, so that the bottom of the hole is substantially not form Carbon polymer layer, generally lower relative RF (Radio Frequency) frequency is used in this step; (3) engraving step and polymer deposition step (4) are carried out 'until through hole_complete, in difficult step, 201225176 due to hole The inner surface, especially the inner side of the hole, deposits the polymer, and the vertical isolated ^• The 'implanted ions will not cause damage to the side of the polymer, and the X will be protected. Destroying the polymer at the bottom of the hole allows the reaction to continue downwards, thus ensuring the anisotropy of the entire hole, especially during the compassion process. Capacitive Coupled Plasma (CCP) Technology, can speed up the vertical direction of the job, anisotropic characteristics are better. Therefore, through the above-mentioned deep reaction ion engraving job TSV, with the degree of engraving can reach 5 or more), side The straightness range is within 9 (four) degrees, and the undereut between the mask layer and the hole is smaller than the characteristic of Q.丨_. near. In order to prevent the pedestal riding degree from being too large, the next step (such as conductor deposition) is difficult. Therefore, the traditional BQSch process is used for the engraving method. The addition of a small amount of oxygen in the engraving step cannot form a sufficient protective layer on the side wall. The steps will be protected by the polymer in the step of forming a pit, and the next step of polymer deposition, and each cycle of alternating rhyme and deposition steps will form a pit on the sidewall, and a plurality of such pits are formed. The fan-shaped side wall reduces the smoothness of the sidewall of the through hole. Since the stalks are isotropic, each step will form a pit in the instrument, and the depth will be close to the depth to the downside. In order to prevent the side 劈 ω pull the acne 通 ϋ, π..
在聚合物沉積步驟中形成的用於側壁保護的聚合物的厚Thickness of polymer for sidewall protection formed in the polymer deposition step
個無法解細問題前幾個循 刻触開口的上端）在不停的 度和成分可以進行選擇，既不不能太- 驟中的側壁進行保護又不至於太厚影 但是傳統Bosch刻蝕方法存在一個無洼 環形成的側壁保護聚合物（位於刻蝕開 201225176 刻蝕一聚合物沉積的交替過程中會被逐漸破壞。刻蝕開口上 端的刻蝕形狀無法得到保證。為了解決聚合物在長期刻蝕中 容易被破壞的問題現有技術提出了一些解決方案，有在刻蝕 進行到-定時間後再進行—摘外的聚合物沉積步驟以強化 側壁的保護。也有在刻钮進行到一$時候利用大量〇2將側壁 的聚合物氧化分轉，進-步的將韻形成的溝槽或通孔側 壁暴露出⑽晶财氧化形成SiG2。但是用魏分解聚合物 並形成側挪護的過程不僅時間長而且氧化刺彡成的條件不 易控制。氧氣要與側壁及底部的石夕快速反應，除了要形成等 離子體外’還需要額外的光線如紫外線（uv)照射或者加熱 來使氧更有活性。由於需要使氧原子向晶體糊擴散形成氧 化石夕’所以即使形成了氧化魏護層，其厚度也不易控制， 且過程緩慢。 護 綜上所述現有技術需要有效的方案實現在刻鱗率與保 夠 =面的平衡’使得深孔判錄在向下舰過財側壁能 獲得持續、有效的保護。 【發明内容】 、本發明魏決的技術_是，避免深貴通孔職過程中 通孔侧壁光滑餅低、雜效率降低的問題。 為解決以上技姻題，本剌提供的深料孔難方法 ^多=環進行的義週期，每個職週期包括一個韻 保護步驟，其特徵在於··所述_步驟供岸· =氣體到放置有待麻判的反應腔，刻_層卿成開 口所述側壁保護步驟供應側壁保護氣體，其中側壁保護氣 201225176 體包括含矽氣體SiF4和含氧氣體反應並沉積在所述開口的側 壁和底部形成氧化矽層。刻蝕氣體包括SiF4和SF6、NF3之 一。刻蝕氣體也可以包括少量C〇2或〇2使側壁更垂直更光 、 门時使母一個看刻钱步驟可以刻银更大的深度如 5-10um。刻钱氣體包括siF4 ’在刻蝕步驟到側壁保護步驟轉 換時提高SiF4的供氣量。 側壁保護氣射的含魏體還包括SiH4，其中含氧氣體 是氧氣。 本發明刻蝕方法的技術效果是，通過氣體連續調節方式 在刻飯階段供應SiF4並在趣賴階段通人大量Q2在側壁 形成Si02保護層，從而更好的保護舰形成的深孔側壁，採 用本方法實現了刻餘步驟和側壁保護步驟的平穩+刀換。其中 麻氣體還包括SF6或NF3和碳氧化合物使得側壁上的i扇 形基本/肖失，使其側壁具有良好的光滑度；同時，相比現 有技術在漸變轉換過程中，仍然等效存在刻银效果和聚合 物沉積效果’因此’可姆減少切換時間，提高深孔補姓 效率。 【實施方式】 為使本發明的目的、技術方案和優點更加清楚，下面結 合附圖對本伽作進—步的詳細描述。圖2所示為本發明所 用的等離子刻細的反應構®。等離子反應腔包括腔體 月上體3内已括放置加工基片的基座及下電極33，下電極 十二，疋用來固疋待加卫基片的裝置34，該裝置可以是靜電 〜ESC。靜電失盤上是待加工基片加，基片％的週邊還 201225176 包括邊緣環36用以調節基片邊緣部分的電場及溫度分佈。與 待加工基片3G對應的反應腔頂部包括—氣體分佈裝置1〇，= 氣體喷淋頭。氣财醜絲自氣體供驗置11()的氣體根 據需要的軋體混合比和流量的均勻分佈到待加工基片加表 面。圖2所示的是典型的電容搞合型（ccp)等離子反應器: 本發明方法也可應其他結構_離子反應腔，比：電感 耦合型反應腔（ICP)。 " 叫U ^丨、句休W不赞明万法加工基片時形成的基片結4 圖。圖形化的掩膜層u下是襯底石夕層12。如圖3a所秘 孔石夕雜過程的第-步，魏向反應腔丨中通人祕氣體 點燃等離子並刻她絲層形成開m 口 2仏有第一、 f ’比如5-H)Um，棘度可叫财侧縣_類和❺ °、比如__中添加⑽，⑽氣體_ 魏SlC和SiG2從而可以保護側壁防止被亥_ ^側壁凹坑更小__狀。開口 2q具有—底面Μ禾 =22’職形成的開，_a中顯示的側壁是垂直的 =1倾財__體和其他參_餅也可以是其 種弧形，也可以_虫、^ Γ中現有技術提到的那 化合物，或者添加能二：量側壁保護氣峨 ==現有技術具有更平滑更垂直的形狀。麻 起-定 從新—上，最終在 7 201225176 的形狀減輕一些侧壁的弧度和刻蝕介面的底切（undercut)。 在刻蝕中通入SiF4和C02等氣體可以使刻蝕過程中形成機乎 垂直的側壁，從而使得每個刻敍步驟可以進行更長時間，每 個刻蝕步驟形成的深度可以達到5_10um。本發明除了可以用 於垂直側壁的刻蝕孔，也可以用於其他形狀的刻蝕孔形成過 程。 如圖3b顯示在完成第一步刻蝕之後進入側壁保護步驟， 在側壁保護步驟中通入含石夕氣體如SiH4或SiF4,同時通入含 氧氣體如02。點燃等離子體後通過這含矽氣體和含氧氣體的 反應在刻姓開口 20的底部和侧壁上分別形成一層層 31 ’ 32。由於是通過外部氣體反應生成新的&〇2層的保護層， 所以新生成的彳雜保護層厚度均自，*且可以通過控制反應 時間來獲得可㈣保護層厚度。碰姆财技術中聚合物 構成的側壁保護層更能耐受在刻蝕步驟中的離子轟擊，能夠 在=個深孔判㈣程中保持完整，不f要像現有技術中那 樣需要在進行？個職_聚合物__職添加一個步驟 強化側保5蒦。&〇2 的厚度選擇以能夠在整個深孔石夕刻钮 中保濩側壁’而又能很快在每一步刻蝕開始時被入射的離子 轟擊使底部的31部分被迅速擊穿。由於在刻姓步驟巾有训4 作為刻餘氣體成分’在側娜護的沉積步射制作為 Si02化成的⑪來源時可以實現_妙驟和側壁保護步驟的平 %過’度〃要逐漸提高SiF4和氧氣的供氣量同時減少聊的 t、氣里即可。⑽也可以和腿混合使用使娜的形成速 度加J·夬’ 魏護步驟姻時間，提高整體雜速率。 201225176 圖3C顯示在第二個刻蝕步驟令底 射的等離子絲後職㈣得卿續 Q2層被局速入 圖3d顯示在職到第二深度後再次進第二深度。 驟，形成_瞧護層32和底部^側壁保護步 形成的深孔内壁。 _卩保鉍31以保護新職 口此細多次職，懿護步驟的㈣循環直到達到 目W果度，完成整個深孔_刻^ _本發财法的側壁 保濩步驟可以在整個韻過程帽得更有效的側壁保護，同 時減少額外健保護的步驟，加快整體的_崎率。由於 本發明採㈣更強的㈣保護，所崎—個韻步驟可以持 續更長時間而不會被破壞，所以本發明每—個韻步驟可以 細罙度制5-1Gum甚至更高。而且_本發财法形成側 壁保護層的過料需外的輻射或加熱裝置，可簡單有效 的形成厚度可控的側壁保護層。 /在不偏離本發明的精神和範_情況下還可以構成許多 有很大差實補。應當理解，除了如所_翻要求所 限定的，本發明不限於在說明書中所述的具體實施例。 【圖式簡單說明】 圖1是現有技術BOSCH刻姓方法示意圖； 圖2疋本發明等離子刻餘裝置的示意圖； 圖3 a- 3d是本發明交替進行刻蝕步驟和側壁保護步驟形 成的碎基片結構圖。 【主要元件符號說明】 1 反應腔 201225176 氣體分佈裝置 掩膜層 氣體供應裝置 襯底矽層 開口 底面 側壁 基片The inability to solve the problem, the first few of the first steps of the opening of the opening) can be selected in the non-stop degree and composition, neither can be too - the side wall of the step is protected and not too thick but the traditional Bosch etching method exists A sidewall-protecting polymer formed by a ring-free ring (which is gradually destroyed during the etching process of etching a polymer deposit in 201225176. The etching shape at the upper end of the etching opening cannot be guaranteed. In order to solve the long-term engraving of the polymer Problems that are easily destroyed in the etch The prior art proposes some solutions, which are carried out after the etching is carried out for a certain period of time - an external polymer deposition step to enhance the protection of the sidewalls. The polymer of the sidewall is oxidized by a large amount of ruthenium 2, and the trench or via sidewall formed by the rhyme is exposed to (10) crystallized and oxidized to form SiG2. However, the process of decomposing the polymer and forming the side care is not only The time is long and the conditions for oxidizing the hedgehog are not easy to control. The oxygen reacts rapidly with the sidewalls and the bottom of the stone, in addition to forming a plasma, it needs extra Wires such as ultraviolet (uv) irradiation or heating to make oxygen more active. Because of the need to diffuse oxygen atoms into the crystal paste to form oxidized oxides, even if an oxidized Wei sheath is formed, the thickness is not easily controlled, and the process is slow. In summary, the prior art requires an effective solution to achieve a balance between the engraving rate and the sufficient surface. This allows the deep hole to be judged in the downward direction of the ship to obtain continuous and effective protection. [Invention] Wei's technology _ is to avoid the problem of low smoothness and low impurity efficiency of the through-hole sidewalls in the process of deep and transparent tunnels. In order to solve the above technical problems, the deep hole method provided by the company is difficult. The meaning cycle, each duty cycle includes a rhyme protection step, characterized in that: the step _ step for the shore · gas to the reaction chamber to be judged, the layer _ layer is formed into the opening side wall protection step supply side wall a shielding gas, wherein the sidewall protective gas 201225176 comprises a cerium-containing gas SiF4 and an oxygen-containing gas reacted and deposited on the sidewalls and the bottom of the opening to form a ruthenium oxide layer. The etching gas includes SiF4 and SF6, NF3 1. The etching gas may also include a small amount of C〇2 or 〇2 to make the sidewalls more vertical and lighter, and the gate can make the silver a greater depth such as 5-10 um when the door is viewed. The engraved gas includes siF4' The etching step increases the gas supply amount of the SiF4 when the sidewall protection step is switched. The Weifang body of the sidewall protection gas jet further includes SiH4, wherein the oxygen-containing gas is oxygen. The technical effect of the etching method of the present invention is that the gas is continuously regulated. SiF4 is supplied in the stage of carving and a large number of Q2 is formed in the side of the stage to form a SiO2 protective layer on the sidewall to better protect the deep hole sidewall formed by the ship. This method is used to realize the smooth + knife change of the step and the side wall protection step. The hemp gas also includes SF6 or NF3 and carbon oxides, so that the i-shaped fan on the side wall is substantially/disappeared, so that the sidewall has good smoothness; at the same time, compared with the prior art, in the process of gradual conversion, the equivalent is still present. Silver effect and polymer deposition effect 'so' can reduce the switching time and improve the efficiency of deep hole filling. [Embodiment] In order to make the objects, technical solutions and advantages of the present invention more comprehensible, a detailed description of the present embodiment will be made in conjunction with the accompanying drawings. Figure 2 shows the plasma etched reaction structure used in the present invention. The plasma reaction chamber includes a pedestal and a lower electrode 33 in which the processing substrate is placed in the upper body 3 of the cavity, and a lower electrode 12, which is used to fix the device 34 to be cured, and the device may be static electricity~ ESC. The electrostatic loss plate is the substrate to be processed, and the periphery of the substrate is also 201225176. The edge ring 36 is included to adjust the electric field and temperature distribution of the edge portion of the substrate. The top of the reaction chamber corresponding to the substrate to be processed 3G includes a gas distribution device 1 〇 = a gas shower head. The gas from the gas supply test 11 () gas is evenly distributed to the surface to be processed plus the surface according to the required rolling mixture ratio and flow rate. Figure 2 shows a typical capacitor-integrated (ccp) plasma reactor: The method of the present invention can also be applied to other structures _ ion reaction chambers, ratio: inductively coupled reaction chamber (ICP). " Called U ^ 丨, 句休W does not praise the substrate knot 4 formed when processing the substrate. Under the patterned mask layer u is a substrate layer 12. As shown in Fig. 3a, in the first step of the hole-hole process, the Wei-to-reaction chamber ignites the gas and ignites the plasma, and engraves her silk layer to form the opening m. The first, f', such as 5-H) Um The spine can be called the financial side county _ class and ❺ °, such as __ added (10), (10) gas _ Wei SlC and SiG2 can thus protect the sidewall from being smaller than the sidewall __ shape. The opening 2q has an opening formed by the bottom surface, and the side wall shown in the _a is vertical. =1 The body of the __ body and other ginseng cakes may also be curved, or may be worms, ^ The compound mentioned in the prior art, or the addition of energy: the amount of sidewall protection gas 峨 = = the prior art has a smoother and more vertical shape.麻起-定 From the new-up, and finally in the shape of 7 201225176 to reduce the curvature of some sidewalls and the undercut of the etch interface. The introduction of gases such as SiF4 and CO2 in the etching allows the formation of vertical sidewalls during the etching process, so that each engraving step can be carried out for a longer period of time, and each etching step can be formed to a depth of 5-10 um. The present invention can be used for etching holes of other shapes in addition to etching holes for vertical sidewalls. As shown in Fig. 3b, after entering the first etching step, a sidewall protection step is carried out, in which a gas containing a gas such as SiH4 or SiF4 is introduced, and an oxygen-containing gas such as 02 is introduced. After the plasma is ignited, a reaction of the helium-containing gas and the oxygen-containing gas forms a layer 31' 32 on the bottom and the side walls of the opening 20, respectively. Since the new & 2 layer of protective layer is formed by the external gas reaction, the newly formed doped protective layer is thick, and the thickness of the protective layer can be obtained by controlling the reaction time. The sidewall protective layer formed by the polymer in the technology is more resistant to ion bombardment in the etching step, and can be kept intact in the depth of the hole. It should be carried out as in the prior art. Employee_polymer__ job adds a step to strengthen the side protection 5 蒦. The thickness of the & 〇2 is selected so as to be able to protect the sidewalls in the entire deep hole, and the ions that are incident at the beginning of each etching are quickly bombarded so that the bottom portion 31 is quickly broken down. Because in the engraved step, there is a training 4 as a residual gas component. When the deposition step of the side protection is made into the source of the SiO2 formation, the gradual and side protection steps can be achieved. The gas supply of SiF4 and oxygen can be reduced at the same time. (10) It can also be mixed with the legs to increase the formation speed of Na and increase the overall impurity rate. 201225176 Figure 3C shows the plasma wire after the second etching step. (4) After the Q2 layer is pushed in. Figure 3d shows the second depth after the in-service to the second depth. The inner wall of the deep hole formed by the protective layer 32 and the bottom side protection step is formed. _ 卩 铋 铋 31 to protect the new job, this fine multiple times, to protect the steps of the (four) cycle until the goal is achieved, complete the entire deep hole _ engraved ^ _ this wealth of the side wall protection steps can be in the whole rhyme The process cap provides more effective side wall protection while reducing the extra health protection steps and speeding up the overall _ saki rate. Since the present invention adopts (4) stronger (four) protection, the steps of the rhyme-rhythm can be continued for a longer period of time without being destroyed, so that each of the rhyme steps of the present invention can be finely 5-1 Gum or even higher. Moreover, the present financing method forms a radiation or heating device for the side wall protective layer, which can easily and effectively form a sidewall protective layer with a controlled thickness. / It can be constructed without much deviation from the spirit and scope of the present invention. It is to be understood that the invention is not limited to the specific embodiments described in the specification, except as defined by the claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a prior art BOSCH engraving method; FIG. 2 is a schematic diagram of a plasma engraving apparatus of the present invention; FIG. 3 a - 3d are fragmentary groups formed by alternately performing an etching step and a sidewall protection step of the present invention; Piece chart. [Main component symbol description] 1 Reaction chamber 201225176 Gas distribution device Mask layer Gas supply device Substrate layer Opening Bottom Side wall Substrate
Si02 層Si02 layer
Si02 層 下電極 裝置 邊緣環 10Si02 layer lower electrode device edge ring 10