591745 玖、發明說明： 【發明所屬之技術領域】 本發明係有關於-種半導體裝置製程，更明確而言，係關於 種在半導體裝置之深溝槽結構上形成淺溝槽之方法。 【先前技術】 …在半導體之9G奈米的製程中，有時需要在已經填人複晶石夕的 深溝槽結構上，形成淺溝槽以供後續製程使用。591745 发明 Description of the invention: [Technical field to which the invention belongs] The present invention relates to a semiconductor device manufacturing process, and more specifically, to a method for forming shallow trenches on a deep trench structure of a semiconductor device. [Previous technology] ... In the 9G nanometer semiconductor manufacturing process, sometimes it is necessary to form shallow trenches on deep trench structures that have been filled with polycrystallites for subsequent processes.
圖la至圖Id係顯示先前技術中用以在深溝槽結構上形成淺 溝槽之方法的各步驟。為簡化起見，僅顯示深溝槽構造之上部。 按照一般深溝槽之形成程序，係在矽基底上形成墊氧化層、墊氮 化層已構成一中間結構，再於該中間結構中形成一深 中，入複晶料。於該等财，元件符號1Q表_基底，n表 示環狀氧化層、12表示填入深溝槽中最上層之複晶矽，13為墊 氧化層，14為墊氮化層。 在深溝槽結構完成之後，先在整體結構上形成一層薄薄的棚 墊層15,此襯墊層15可為氮化層，通常為叫队。接著，在該棚 塾層15上形成一層薄薄的非晶矽層16，如圖以所示。Figures la to Id show the steps of a method for forming a shallow trench on a deep trench structure in the prior art. For simplicity, only the upper portion of the deep trench structure is shown. According to the general deep trench formation procedure, a pad oxide layer and a pad nitrogen layer are formed on a silicon substrate to form an intermediate structure, and then a deep middle is formed in the intermediate structure, and a compound crystal is inserted. In these properties, the component symbol 1Q refers to the substrate, n indicates a ring-shaped oxide layer, 12 indicates the topmost polycrystalline silicon filled in the deep trench, 13 is a pad oxide layer, and 14 is a pad nitride layer. After the deep trench structure is completed, a thin canopy cushion layer 15 is formed on the overall structure. This cushion layer 15 can be a nitride layer, usually called a team. Next, a thin amorphous silicon layer 16 is formed on the roof layer 15 as shown in the figure.
接下來，實行BF2離子之斜角佈植，亦即，將BF2離子以一 選定之角度傾斜打在該非晶碎層16上以將吨離子植入非晶每 層16。由於BF,離子係以一斜角佈值，深溝層部分有一個角落以 及一個側邊的非晶矽層16的部分不會被佈植到。之後藉由邛分 #刻處理’將非晶石夕層16未被佈植BF2離子的部分移^^ 離子植入的非晶石夕層16之部分，如圖lb所示。如所示 非b曰石夕層16被移除的部分下的襯墊層15之部分係暴露出來。 接下來，利用濕蝕刻法，將暴露出來的襯墊層15 如圖lc所示。 Μ为移除 參照圖id，然後，利用留下的襯塾層15部分作為 由乾蝕刻法將複晶矽12挖出一個淺溝槽’非晶矽層心 : 階段被一併移除。最後移除殘餘的襯墊層15。 J:\menu\pending-92\92357.doc 5 然而，習知技術之做法有一些問題。在圖lc所示步驟中，採 用濕蝕刻法，將材料為氮化物之襯墊層15蝕刻出開口，會產2 凹蝕(undercut)的現象。此外，在利用乾蝕刻法於複晶矽12"中形 成淺溝槽時，由於氮化物對矽的蝕刻選擇比大約僅為丨：，丄 限於深溝槽尺寸大小，氮化物的厚度有一定限制，因此，在蝕= ，晶矽12時，氮化物之襯墊層15並不足以作為良好的硬罩，二 得所形成的淺溝槽的輪廓無法達到預期而有所變形，如 所示者。 _ ία宁 +因此，需要一種克服上述問題的解決之道。本發明即滿足此項 藏求。 【發明内容】 本發明之目的為提供一種於深溝槽結構上形成淺溝槽之方法，盆 所形成之淺溝槽係具有良好的輪廓。 〃 根據本發明之一方面，一種於深溝槽結構上形成淺溝槽之方法中， 該深溝層結構至少包含-基底、形餘該基底上的墊氧化層、塾氮化 層’於其上形成有墊氧化層以及魏化狀基底㈣成—骑槽，該深 溝槽中係至少填人複晶⑨，該方法包含步驟有：於深溝機構上形成一 襯塾層；於該她層上形成-非晶石夕層；將選定之離子植入該非晶石夕層 之。Ρ分區域；使該非騎層氧似形成—氧化層，其巾該非晶梦層有植 入該選定離子之區域以及未被植人該敎離子之區域所形成的氧化層 厚度不同，該深溝槽之複晶石夕上方有一部分區域的氧化層之厚度較厚曰; 移，部分該氧化層，以使該氧化層厚度較_區域被移除，而厚度較厚 的部分有麵的祕層；雜未被制餘的氧化層覆蓋馳塾層部分， 使破移除之縫層部分下的複晶絲露出；以及移除暴露出的複晶石夕以 形成淺溝槽。 根據本發明之另-方面’該深溝槽結構上形成淺溝槽之方法中，該 2係選定以使該非晶销有植人該選定離子之區域所形成的氧化層 厚度較薄’而未概人該奴離仅區域成魏化層厚度較厚。 根據本發明之又-方面，該深溝構上形錢溝槽之方法中該 6 J:\menu\pending-92\92357.doc 591745 選定之離子為n2+離子 該 【實施方式】 將參照圖式詳細說明本發明之方法。 囷2a至圖2f係顯示根據本發明之用以⑽ 淺溝槽之枝的各㈣。職倾見，僅構上形成 部。其中元件符號2〇表示矽基底，2環:構造之上 填入深溝槽中最上層之複晶石夕，層、22表示 層薄薄的襯後，先在整體結構上形成― 相同。接著，成—㈣相非晶韻26，與先前技術 26。由於N+離^明石夕層％上以將N2+離子植入非晶石夕層 一個側邊的非曰加 木溝層部分有一個角落以及 接人日矽層26的部分不會被佈植到。 層的非:二’二熱氧化法或其他適當方式使整體結構表面最上 如Si〇2。由=+氧化以形成氧化層27，其成份為石夕氧化物，例 27的厚度h 2離子植人非晶.26之部分，所形成的氧化層 厚度較小，产古斤不,有N2離子植入的區域，所形成的氧化層 如圖2b所^ Ν2+離子植入的區域，所形成的氧化層厚度較大， 後氧化層雖然本實施例係採用Ν2+離子，但只要能夠造成之 接下度有所不同的離子均可使用。 度較薄的區域利用適當的蝕刻法，將氧化層27部分移除，其中厚 27，Γ ^被完全移除，而厚度大的區域則留下部分的氧化層 如團2c所示。 7 J:\menu\pending-92\92357.doc 、利用上錄賴訂的氧化層27之部分作為硬罩 刻法等方式將未被氧化層27覆蓋的襯墊層乃 9 ° 的緣故，深溝槽結構上部開口側邊的襯塾層25 田於方向 姓刻掉，而會留下以作為保護。 " 般而言不會被 然後，利用前述留下的氧化層27為硬罩， 他任何適當的方式，移除暴露出來的二 如圖2e所示。 叫成淺溝槽， 最後，將剩餘的氧化層27以及襯塾層25移除，如圖 。 根，本實施例，由於氧化層27之材料Si〇2對複晶石夕之姓刻 選擇比較㊉，可高達i : 8〇至i : 2⑻，因此該氧化層27可在後 =姓刻處理中作為良好的硬罩，從而使得所形成的淺溝槽輪廊 艮好。 ^明已Μ施例作詳細制，然而上述實_僅為例示性說明 ，明之原理以及功效，並非用於聞本發明。熟知此項技蔹者 可知，不轉本發明之精神與_的各種修正、變更均可實 本發明之保護範圍係如所附之巾請專利範圍所界定。 【圖式簡單說明】 下列®式巾’並賴照實際尺寸比{_製，僅為顯示各部分 相關的關係，此外，相同的^件符號表示相同的部分。 圖1&至® Id侧示先前技術中用以在賴槽結構上形成淺 /冓槽之方法的各步驟；以及 圖2a至圖2f係顯示根據本發明之用以在深溝槽結構上形成 淺溝槽之方法的各步驟。 — J:\menu\pending-92\92357.doc 8 591745 元件符號說明： 10 基底 11 環狀氧化層 12 複晶矽 13 墊氧化層 14 墊氮化層 15 襯墊層 16 非晶矽層 20 基底 21環狀氧化層 _ 22 複晶矽 23 墊氧化層 24 墊氮化層 25 襯塾層 26 非晶矽層 27 氧化層 9 J :\menu\pending-92\92357.docNext, an oblique implantation of BF2 ions is performed, that is, BF2 ions are slanted on the amorphous fragment layer 16 at a selected angle to implant tons of ions into each amorphous layer 16. Due to the BF, the ions are distributed at an oblique angle, and a portion of the deep trench layer having a corner and a side of the amorphous silicon layer 16 will not be implanted. After that, the portion of the amorphous stone layer 16 that is not implanted with BF2 ions is moved by the engraving process # ^, as shown in FIG. 1b. As shown, a portion of the cushion layer 15 below the portion where the stone eve layer 16 is removed is exposed. Next, the exposed pad layer 15 is shown in FIG. 1c by a wet etching method. Μ is removed. Referring to FIG. Id, the remaining part of the liner layer 15 is used as a shallow trench to dig out the polycrystalline silicon 12 by the dry etching method. The amorphous silicon layer core is removed in stages. Finally, the remaining cushion layer 15 is removed. J: \ menu \ pending-92 \ 92357.doc 5 However, there are some problems with the practice of know-how. In the step shown in FIG. 1c, the wet etching method is used to etch the opening of the liner layer 15 made of nitride, which results in an undercut phenomenon. In addition, when shallow trenches are formed in the polycrystalline silicon 12 by dry etching, the nitride-to-silicon etching selection ratio is only about 丨:, 丄 is limited to the size of deep trenches, and the thickness of the nitride is limited. Therefore, at the time of etch = crystalline silicon 12, the nitride liner layer 15 is not sufficient as a good hard cover, and the contour of the shallow trench formed by the second method cannot be expected and deformed, as shown in the figure. _ ία 宁 + Therefore, a solution is needed to overcome the above problems. The present invention satisfies this need. SUMMARY OF THE INVENTION The object of the present invention is to provide a method for forming shallow trenches on a deep trench structure. The shallow trenches formed by the basin have a good profile. 〃 According to an aspect of the present invention, in a method for forming a shallow trench on a deep trench structure, the deep trench layer structure includes at least-a substrate, a pad oxide layer on the substrate, and a hafnium nitride layer formed thereon. A pad oxide layer and a Weihua-like substrate are formed into a riding trough. The deep trench is filled with at least polycrystalline silicon. The method includes the steps of: forming a liner layer on the deep trench mechanism; and forming on the other layer- Amorphous stone layer; implanting selected ions into the amorphous stone layer. Sub-region; make the non-riding layer oxygen-like oxide layer, the amorphous dream layer has different thickness of the oxide layer formed in the area where the selected ion is implanted and the area where the thallium ion is not implanted, the deep trench A part of the oxide layer above the complexite is thicker; move, part of the oxide layer, so that the thickness of the oxide layer is removed from the area, and the thicker part has a facet secret layer; The unrefined oxide layer covers the galvanic layer portion to expose the polycrystalline wires under the removed seam layer portion; and the exposed polycrystalline stone is removed to form a shallow trench. According to another aspect of the present invention, in the method of forming a shallow trench on the deep trench structure, the 2 is selected so that the thickness of the oxide layer formed in the region where the selected pin is implanted with the amorphous pin is thinner. The area where the people are slaves is thick and thick. According to another aspect of the present invention, in the method for forming a deep groove on the deep groove, the 6 J: \ menu \ pending-92 \ 92357.doc 591745 is selected as the n2 + ion. [Embodiment] will be described in detail with reference to the drawings The method of the present invention will be described. The ridges 2a to 2f show the ridges of the branches used for the shallow groove according to the present invention. Professional insights, only the formation department. Among them, the component symbol 20 indicates a silicon substrate, and 2 rings: the structure is filled with the top polycrystalline stone in the deep trench, and the layer 22 indicates a thin layer of lining, which is first formed on the overall structure-the same. Next, the amorphous phase 26 is formed, in contrast to the prior art 26. Since the N + ion is added to the Akashi layer, the N2 + ions are implanted into the amorphous layer, and the corner of the non-Jiamugou layer on one side has a corner, and the portion that contacts the silicon layer 26 will not be implanted. The non-layer: two 'two thermal oxidation method or other appropriate means to make the surface of the overall structure as SiO2. The oxidation layer 27 is formed by = + oxidation, and its composition is Shi Xi oxide. The thickness h 2 of Example 27 is implanted into the amorphous .26 part. In the area of ion implantation, the oxide layer formed is as shown in FIG. 2b. The area of the N2 + ion implantation has a larger thickness. Although the rear oxide layer uses N2 + ions in this embodiment, as long as it can All ions with different degrees can be used. The oxide layer 27 is partially removed in a thinner region by an appropriate etching method, in which the thickness 27, Γ ^ is completely removed, while the thicker region leaves a portion of the oxide layer as shown in Group 2c. 7 J: \ menu \ pending-92 \ 92357.doc, using the part of the oxide layer 27 recorded above as a hard cover engraving method, etc. The cushion layer that is not covered by the oxide layer 27 is 9 °. Lining layer 25 Tian at the upper opening side of the trough structure is engraved in the direction of surname and will be left for protection. " Generally speaking, it will not be used. Then, using the oxide layer 27 left above as a hard cover, he can remove the exposed two in any suitable way, as shown in Figure 2e. It is called a shallow trench. Finally, the remaining oxide layer 27 and the liner layer 25 are removed, as shown in FIG. Root, in this embodiment, since the material Si02 of the oxide layer 27 has a relatively high selection of the name of the polycrystalline stone, it can be as high as i: 80 to i: 2, so the oxide layer 27 can be processed after the last name. Medium as a good hard cover, so that the shallow grooves formed are good. ^ Ming has been detailed examples, but the above description is only illustrative, the principle and effect of Ming is not used to smell the present invention. Those skilled in the art will know that various modifications and changes without changing the spirit of the present invention can be implemented. The scope of protection of the present invention is defined by the scope of the attached patent. [Brief description of the drawings] The following ®-style towels are based on the actual size ratio {_ system, and only show the relationship between each part. In addition, the same ^ symbol indicates the same part. 1 & Id show the steps of a method for forming a shallow / groove on a trench structure in the prior art; and FIGS. 2a to 2f show a method for forming a shallow trench on a deep trench structure according to the present invention Steps of the trench method. — J: \ menu \ pending-92 \ 92357.doc 8 591745 Description of component symbols: 10 substrate 11 ring oxide layer 12 polycrystalline silicon 13 pad oxide layer 14 pad nitride layer 15 pad layer 16 amorphous silicon layer 20 base 21 ring oxide layer 22 polycrystalline silicon 23 pad oxide layer 24 pad nitride layer 25 liner layer 26 amorphous silicon layer 27 oxide layer 9 J: \ menu \ pending-92 \ 92357.doc