200835822 九、發明說明： 【發明所屬之技術領域】 用於得到表面 本發明係關於在矽晶圓之高溫熱處理中 平坦之矽晶圓的熱處理方法。 【先前技術】 2藉丘克拉斯(cz)法而拉起之矽單結晶錠製造矽晶 ?、v驟巾’係以減低晶圓表層之結晶缺陷、改200835822 IX. DESCRIPTION OF THE INVENTION: TECHNICAL FIELD OF THE INVENTION The present invention relates to a heat treatment method for a flat tantalum wafer in a high temperature heat treatment of a tantalum wafer. [Prior Art] 2 The single crystal ingot is pulled up by the Chuklas (cz) method to make twin crystals, and the v-slips are used to reduce the crystal defects of the wafer surface.
度（微觀粗糙度’心⑽他咖）等為目的^施謂 c以上之熱處理。 例如，於日本專利第3292545號公報（專利文獻！）中， δ己载有於㈣性氣體或雜氣體環境巾，對^圓 既 定時間之1刚。(：以上之高温減理後，降溫至⑼代以 :’亚將上=環境置換為1氣的熱處理方法。根據此種熱 :理方法’藉由於晶圓表面形成氮化膜’可不致於使晶圓 表面之粗度增大，而抑制起因於晶圓之氧化膜缺陷的發 生。 t晶圓表面之㈣子，係藉由於還原性氣體或惰性氣體 、衣兄下進行11GGC以上之高溫熱處理，為了穩定化而 進仃再排列，使晶圓表面成為原子等級呈平坦化的構造。 於上述再排列中，晶圓表面係形成有於表面上且有原子 . . (step.te；rac；)# &將熱處理前之♦晶圓進行研磨加工後，藉由原子間力顯 U鏡（AFM)所測定之細微表面粗度（微觀粗糙度），係每3 96149869 6 200835822 /zmx3//m之Rms(均方粗度）為〇15〜〇 2nm，相對於此， 如上述般經平坦化之矽晶圓表面藉AFM所測定的Rms為 0· Inm左右。 由此可知，藉由上述般之熱處理，可達到表面粗度之減 低化。 ， 上述階梯.台構造之台寬度，會因減小石夕結晶之偏角 (off angle)減小而變大，於熱處理後之AFM觀察中，可 確認到更明確之階梯•台構造。 例如，於曰本專利特開平8_2644〇1公報（專利文獻 中e載，使面方位（_)之單結晶⑦晶圓於（刪）面之垂直 線<110〉方向上傾斜〇.〇1〜〇 2。之角度並切片，予以洗淨 處理後’在氬環境中以議。c進行減理，藉此可 形成階梯•台構造。 然而’於上述熱處J里中，·5J*知因環境而使熱處理後之石夕 晶圓表面粗度不同。例如，於氬氣體環境下進行熱處理 後’ P♦溫至7GG°C再將氬置換為氮並於氮氣體環境下進行 出爐的情況下，每3"mx3"之Rms為約〇〇7⑽。相對 於此’在氫氣環境下進行熱處理後，降溫至7〇〇ΐ再將氫 置換為ILJE於氮氣體環境下進行出爐的情況下，心 O.lnm。 本發明者等人檢討了發生此種表面粗度相異之原因，結 η ’此現象並非受至"100。。以上之高溫熱處理時之 乳體環境的影響，而是受到上述高溫處理後之降溫或降溫 後所置換的氣體環境的影響。 96149869 7 200835822 【發明内容】 本^明係根據上述檢討結果，進—步加以 =目的在於提供一種石夕晶圓之熱處理方法，係針= 卩上之尚溫熱處理而於原子等級經平坦化之 =表面’於高溫減理後，藉由達職料 二 =::溫:段中之爐内環境的最適當化，而可保持= 曰曰貝、以白梯·台構造，並較習知技術更加減低晶Degree (micro-roughness 'heart (10) his coffee), etc. for the purpose of ^ the heat treatment above c. For example, in Japanese Patent No. 3292545 (Patent Literature!), δ is contained in a (iv) gas or a heterogas environmental towel, and is set to be a predetermined time. (: After the above high temperature reduction, cool down to (9) on behalf of: 'Asian will = environmental replacement for 1 gas heat treatment method. According to this heat: the method 'by forming a nitride film on the surface of the wafer' can not Increasing the thickness of the wafer surface to suppress the occurrence of defects in the oxide film caused by the wafer. The (four) sub-wafer surface is subjected to high-temperature heat treatment of 11 GGC or more by a reducing gas or an inert gas. In order to stabilize, the wafer surface is rearranged to make the surface of the wafer flattened at an atomic level. In the above rearrangement, the surface of the wafer is formed on the surface and has atoms. (step.te;rac; )# & The fine surface roughness (micro-roughness) measured by atomic force U-mirror (AFM) after grinding the wafer before heat treatment, every 3 96149869 6 200835822 /zmx3// The Rms (mean squareness) of m is 〇15 to 〇2 nm. On the other hand, the Rms measured by the AFM on the surface of the wafer which has been flattened as described above is about 0·Inm. The heat treatment is generally used to reduce the surface roughness. The width of the step and the table structure is increased by reducing the off angle of the crystal, and a more detailed step/stage structure can be confirmed in the AFM observation after the heat treatment. For example, In Japanese Patent Laid-Open No. Hei 8-2644〇1 (in the patent document, the single crystal 7 wafer of the plane orientation (_) is inclined in the direction of the vertical line <110> The angle is sliced and washed, and then it is reduced in an argon atmosphere to form a step-and-station structure. However, in the above-mentioned heat J, the 5J* is caused by the environment. After the heat treatment, the thickness of the surface of the wafer is different. For example, after heat treatment in an argon atmosphere, the temperature is increased to 7 GG ° C, and then argon is replaced by nitrogen and discharged under a nitrogen atmosphere, every 3 & quot The mms of mx3" is about (7(10). In contrast to the case where the heat treatment is carried out in a hydrogen atmosphere, the temperature is lowered to 7 〇〇ΐ and then the hydrogen is replaced by ILJE in a nitrogen atmosphere, and the core O.lnm The inventors and the like reviewed the causes of such surface roughness differences. The knot η 'this phenomenon is not affected by the influence of the above-mentioned high temperature heat treatment of the milk environment, but the influence of the gas environment replaced by the above-mentioned high temperature treatment after cooling or cooling. 96149869 7 200835822 Contents] According to the above review results, the purpose of this method is to provide a heat treatment method for the Shixi wafer, which is a heat treatment at the atomic level and a flat surface at the atomic level. After the high temperature reduction, by the material 2 =:: temperature: the most appropriate environment in the furnace, can maintain = mussel, white ladder and Taiwan structure, and more reduced crystal than the conventional technology
面粗度（微觀粗趟度），且可穩定地形成此種晶圓之表面: 本發明之矽晶圓之熱處理方法，係於矽晶圓表面上形 階梯•台構造者，其特徵為’將梦晶圓於還原性氣體或惰 性氣體環境之熱處理爐内，卩110(rc以上進行歸理後， 於降溫時在爐内溫度為以上之階段將爐内氣體環境 設為氬並持續將氬氣導入至爐内’直至將石夕晶圓出爐 為止，藉此保持上述矽晶圓表面之階梯•台構造，且使每 3//mx3/zm之均方粗度Rms成為〇· 〇6ηιη以下。 如此，針對藉110CTC以上高溫熱處理而於原子等級經 平坦化之矽晶圓表面，將自高溫熱處理後之降溫階段至出 爐為止的爐内環境設為氬氣，藉此可保持上述晶圓表面之 階梯·台構造，並較習知技術更加減低晶圓表面粗度。 於上述熱處理方法中，較佳係至少至載置有上述矽晶圓 之晶舟（wafer boat)之晶圓載置部整體取出爐外為止，持 續將氬氣導入爐内。 在自5 0 0 C至將石夕晶圓進行出爐為止的降溫時，藉由保 持為使石夕晶圓表面由氬氣所包覆之狀態，則可不致使石夕晶 96149869 8 200835822 圓表面之階梯•台構造崩壞，而維持高平坦度。 .爐===:舟之出爐時’使該晶舟整體被自 加提高維持上料晶图表面平坦度的效果。 底邻門在將上述晶舟自爐底部進行出爐時，自炒 。鳥/s«下 …流速為°.°192—上且 由以鐵i氣保護經出擔夕Η问士 • 卜η而盧曰圓表面的觀點而言，較佳係 °又為上述耗圍内的氣體流速。 _如上述般’根據本發明，針對藉1HHTC以上之高溫熱 =而於原子等級經平坦化之石夕晶圓表 ;： =二之降溫階段中之爐内氣體環境的 ： !’結果可較習知技術更加減低晶圓之表面粗度，且二 疋地形成此種晶圓之表面。 了 t |【實施方式】 以下，詳細說明本發明。 本發明之石夕晶圓之熱處理方法中，首先H曰日圓 原性氣體或惰性氣體之環境的熱處理爐内，卩 上進行熱處理。上述高溫熱處理步驟後之降溫 ，為5〇rc以上之階段將爐内環境設為氯氣：爐： 矽晶圓出爐為止，持續將氬氣導入爐内。 本發明之特徵在於’經由此種熱處理步驟，保持石夕晶圓 表面之階梯•台構造，且借各q 使母之.成為〇.〇6nm 96149869 200835822 以下。 亦即，本發明係根據下述發現而完成者：此種 階段之爐内環境的置換傭晶圓表面粗度減低疋：; 地形成更平坦化之表面的有效率之手段。 、本發明中，進行熱處理的矽晶圓並無特別限定，例如可 為將藉丘克拉斯（cz)法、浮動帶（floating z〇ne，Fz)法 等所得之矽單結晶予以切片後，經鏡面加工之矽晶圓基 板、磊晶晶圓、SOI晶圓等之任一種。 土 如上述，本發明之高溫熱處理步财，係將⑦晶圓 =性氣體或情性氣體之環境下，卩iΌ以上進行熱處 低此=盈熱處理係以尋求石夕晶圓表層之結晶缺陷的減 :處::善表面粗度等，而形成階梯·台構造為目的所進: 熱處理中’為了保持矽晶圓之潔淨，而設為還原性 氨等鐘，可舉例如氫、 =X，作為惰性氣體，可舉例如氛 氣體可使用1種或2種以μ々、日人Α 此4 或氬氣。種戈2種以上之混合氣體。通常係使用氫氣 =且=述高溫熱處理前’由保持矽晶 二ί係事先將石夕晶圓保持於惰性氣體環境内 另卜’由減低晶圓結晶缺陷、改善表面 & 言，上述熱處理溫度較况 又、硯點而 以上之高溫進彳于& ’如上述般，較佳為依 间，皿進仃。此南溫熱處理時間較佳為〇.5~24 96149869 200835822 小時左右。 j發％之熱處理方法中，上述高溫熱處理步驟後，在降 之爐内溫度為5〇〇°C以上的階段，將爐内環境自還原 性^體或惰性氣體置換為氬氣。 ” 藉由作成為氬氣，可解決f知技術中降溫時平 的問題。 一又〜 此時，在高溫熱處理之環境為氬氣的情況下，即使在降 溫過程中，亦可保持原本的環境。 尚且最仏係100%之氬氣環境，於熱處理時，在得到 f他效果的目的之下，亦可導人少量之氬氣料的氣體種 類0 上述高溫熱處理後，將置換為氬氣的溫度設為50(rc以 上0 在上述置換時之溫度為未滿500^的情況下，難以達 表面平坦化。 # #從:，較佳係於50(rc以上之溫度下將環境置換為氬 氣，藉此，可更加減低藉上述高溫熱處理而於原子等級經 平坦化之晶圓的表面粗度惡化。 Ί W上述熱處理後之矽晶圓，係將爐内環境設為氬氣後，降 溫至可進行出爐之溫度後再進行出爐，較佳係在完成出爐 k 為止，將氬氣持續導入至爐内。 a 在將上述矽晶圓載置於晶舟上的情況下，較佳係至少至 上述晶舟之晶圓載置部整體取出爐外為止，持續將氬2 入爐内。 96149869 11 200835822 上、在自500 c至矽晶圓進行出爐為止的降溫時，藉 •古保持為使石夕日日圓表面由氬氣所包覆，則可不致於使上述 _ Γ3 /皿，處理所形成之石夕晶圓表面的階梯•台構造崩壞，而 維持南平坦度。 再者’較佳係於上述晶舟之出爐時，使該晶舟整體被自 爐内所流出之氬氣所包圍的狀態。 相較於其他氣體’氬氣純容易㈣於_晶圓上，至從 ^之開口部取出上述晶舟為止，將氬氣持續導入至爐内， 猎此於出爐後，可使氬氣暫時殘留覆蓋於石夕晶圓表面。 、/此，至訂述晶舟完全取出至爐外為止，持續將氬氣 ¥入至爐内’藉此可使自爐内所流出之氯氣將晶舟整體包 後並了 南維持上述石夕晶圓表面平坦度的效果。 在將士述晶舟從爐底部進行出爐時，自爐底部開口部所 流出之氬氣流速，較佳為〇.〇192m/s以上、〇i9〇m/s以 下。 鲁此種範圍之氣體流速，係適合於由氬氣保護經出爐之 晶圓表面。 在上述氣體流速為未滿0.0192m/s時，無法得到由氬氣 所進行之矽晶圓表面的充分保護效果。氣體流速特佳為 0· 05m/s 以上。 .另一方面，在上述氣體流速超過0190m/s的情況下， •即使氣體流速變大，亦無法獲得更佳的效果，且有導致發 塵之虞。 以下，根據實施例，更具體地說明本發明，但本發明並 96149869 12 200835822 不限定於下述實施例。 [實施例1] 首先，將直徑8吋之矽（1〇〇)結晶錠朝<1〇〇>方向以偏 0. 03。進行切片而得到矽晶圓，並對其實施鏡面加工。角 將此矽晶圓載置於晶舟上，填裝於氬氣環境之熱處理 内。於700°C下將爐内自氬氣環境置換為氫氣環境，^ 升溫，於llOOt：下保持1小時，進行熱處理。 仃 其後，進行降溫，於下將爐内自氫氣環境置 氬氣環境後，再降溫’直到將矽晶圓出爐為止 、二 氣導入至爐内。 守、，將氧 然後’在將载置有矽晶圓之晶舟從爐底部之開口部 出爐時’使上述開π部與晶舟之間的氩氣流 = 0· lm/s，將矽晶圓進行出爐。 馬 4:::二圖9顯示上述熱處理步驟中之環境氣體與 /皿度之狀您的流程。 =處理後之侧表面’請測定㈣㈣區 域之表面凹凸像及表面粗度Rms。 圖1表示由AFM觀察所得之矽晶圓的本二 [實施例2〕 之夕日曰圓的表面凹凸像。 —除了將熱處理溫度·t改為副t以外轉依盘 貫施例1相_條件，進行^κ之熱處理。，、-處理後之石夕晶圓表面’藉測 域之表面凹凸像及表面粗度Rms。 圖2表示由㈣觀察所得之石夕晶圓的表面凹凸像。 96149869 13 200835822 [比較例i ] 除了將熱處理溫度11〇〇。(3改為1〇〇〇°C以外，其餘依與 實施例1相同的條件，進行矽晶圓之熱處理。 針對熱處理後之矽晶圓表面，藉Afm测定3 // mx3 // m區 域之表面凹凸像及表面粗度Rms。 圖3表示由AFM觀察所得之矽晶圓的表面凹凸像。 由圖1〜3之照片可知，熱處理溫度為1〇〇(^c的情況（比 _較例1)下，於矽晶圓表面上未形成階梯·台構造，而在 熱處理溫度為11 〇〇°C或12〇〇°c的情況（實施例1、2)下， 明確地確認到階梯•台構造。 表面粗度Rms係於熱處理溫度為丨〇〇〇。〇的情況（比較例 1)下為0· 158nm，相對於此，在110〇π的情況（實施例d 下為0· 047nm，在1200°C的情況（實施例2)為0· 〇49nm， 確認到在1100°C以上的情況下可減低表面粗度。 尚且，在圖1之照片中，在熱處理溫度為110(rc的情 _況（實施例1)下，階梯•台構造之階梯的線為朝右上，另 一方面，於圖2之照片中，在熱處理溫度為的情 況（實施例2)下，階梯•台構造之階梯之線為朝左上，此 係因為使偏角傾斜之方向因晶圓而有些許不同所致。 [實施例3] 、 針對經由如同實施例2進行熱處理後之矽晶圓表面，藉 -AFM測定3μ mx3/z皿區域之表面凹凸像及表面粗度Rms。 圖4表示由AFM觀察所得之矽晶圓的表面凹凸像。 另外’結果與實施例2出現差異的現象，可認定僅為晶 96149869 14 200835822 圓個體差異所致。 [實施例4 ] 二將氬氣以外’其餘依與實施例3相Surface roughness (microscopic roughness), and the surface of such a wafer can be stably formed: The heat treatment method of the tantalum wafer of the present invention is a step-form structure on the surface of a tantalum wafer, which is characterized by ' The dream wafer is placed in a heat treatment furnace of a reducing gas or an inert gas atmosphere, and after rc110 (the above is rc, the gas atmosphere in the furnace is set to argon and the argon is continuously maintained at the temperature above when the temperature is lowered in the furnace. The gas is introduced into the furnace until the stone wafer is discharged, thereby maintaining the step structure of the surface of the tantalum wafer, and the mean square roughness Rms per 3/mx3/zm is 〇·〇6ηιη or less. In this way, for the surface of the germanium wafer which is planarized at the atomic level by the high-temperature heat treatment of 110 CTC or higher, the furnace environment from the cooling stage after the high-temperature heat treatment to the furnace is set as argon gas, thereby maintaining the wafer surface. In the above-described heat treatment method, it is preferable to at least the wafer placing portion of the wafer boat on which the silicon wafer is placed as a whole. Take out the stove, The argon gas is continuously introduced into the furnace. When the temperature is lowered from 500 ° C to the discharge of the Shi Xi wafer, the surface of the Shi Xi wafer is kept covered with argon gas, so that the stone is not caused.夕晶96149869 8 200835822 The step of the round surface • The structure of the table collapses while maintaining high flatness. Furnace ===: When the boat is released, the whole boat is self-added to maintain the flatness of the surface of the loading crystal. The bottom door is self-frying when the above-mentioned crystal boat is discharged from the bottom of the furnace. The bird/s «lower flow rate is ° ° ° 192 - and it is protected by iron and gas. From the viewpoint of η and the surface of the 曰 曰 circle, the preferred system is the gas flow rate within the above-mentioned consumption. _ As described above, according to the present invention, the atomic level is flattened by the high temperature heat of 1 HHTC or higher. The stone wafer table;: = the gas environment in the furnace during the cooling phase: !' The result is that the surface roughness of the wafer is reduced more than the conventional technique, and the surface of the wafer is formed in a second place. t | [Embodiment] Hereinafter, the present invention will be described in detail. In the method, first, heat treatment is performed on the crucible in the heat treatment furnace of the environment of the Japanese yen inert gas or the inert gas. The temperature after the high temperature heat treatment step is 5 rc or more, and the furnace environment is set to chlorine gas: furnace: The argon gas is continuously introduced into the furnace until the wafer is discharged. The present invention is characterized in that "the step of the step of the surface of the stone wafer is maintained by the heat treatment step, and the mother is made by the q." 6nm 96149869 200835822 hereinafter. That is, the present invention is accomplished according to the following findings: the replacement of the surface roughness of the furnace environment in this stage of the furnace is reduced: 有: an efficient means of forming a flatter surface In the present invention, the tantalum wafer to be heat-treated is not particularly limited, and for example, the tantalum crystal obtained by the cz method, the floating z〇ne (Fz) method, or the like may be sliced. Any one of mirror-processed wafer substrates, epitaxial wafers, and SOI wafers. As described above, the high-temperature heat treatment step of the present invention is performed under the environment of 7 wafers = a gas or an inert gas, and the heat is lower than the heat treatment system to seek the crystal defects of the surface layer of the stone wafer. Subtraction:: Good surface roughness, etc., and the purpose of forming a step and a table structure: In the heat treatment, in order to keep the silicon wafer clean, it is a reductive ammonia clock, for example, hydrogen, =X As the inert gas, for example, one type or two types of an atmosphere can be used, such as μ々, Japanese, or argon. Mixing more than two kinds of gases. Usually, hydrogen is used = and = before the high-temperature heat treatment, 'the crystal is kept in an inert gas environment by keeping the twin crystals in advance'. By reducing the wafer crystal defects, improving the surface & The situation is higher, and the above high temperature is in the & 'As above, it is better to enter the room. The heat treatment time of the south temperature is preferably about 5.5~24 96149869 200835822 hours. In the heat treatment method of the % of %, after the high-temperature heat treatment step, the furnace environment is replaced with argon gas from a reducing body or an inert gas at a stage where the temperature in the furnace is lowered to 5 °C or higher. By making argon gas, it can solve the problem of flat temperature reduction in the technology. Once again, at this time, in the case where the high temperature heat treatment environment is argon gas, the original environment can be maintained even during the temperature reduction process. The most argon-based environment is 100% argon. In the heat treatment, under the purpose of obtaining the effect of argon, it can also introduce a small amount of argon gas. The above-mentioned high-temperature heat treatment will be replaced by argon. When the temperature is 50 (rc or more 0), when the temperature at the time of the above replacement is less than 500, it is difficult to achieve surface flattening. # #从:, preferably at 50 (the temperature is higher than rc, the environment is replaced by argon) Therefore, the surface roughness of the wafer which is flattened at the atomic level by the above-described high-temperature heat treatment can be further reduced. Ί W The heat-treated silicon wafer is cooled after the furnace environment is set to argon gas. After the temperature of the tapping can be performed, the furnace is discharged, preferably, the argon gas is continuously introduced into the furnace until the k is completed. a. In the case where the crucible wafer is placed on the wafer boat, it is preferable to at least The wafer loading unit of the wafer boat as a whole Until the outside of the furnace, argon 2 is continuously placed in the furnace. 96149869 11 200835822 When the temperature is lowered from the 500 c to the wafer, the surface is covered with argon gas. It is not necessary to cause the above-mentioned _ Γ 3 / dish to be treated, and the step structure of the surface of the wafer formed by the treatment is collapsed to maintain the south flatness. Further, it is preferable to make the crystal when the wafer boat is discharged. The whole boat is surrounded by the argon gas flowing out of the furnace. Compared with other gases, 'argon gas is easy to (4) on the wafer, and the argon gas is continuously introduced until the wafer boat is taken out from the opening of the ^ Into the furnace, after hunting, the argon gas can be temporarily left over the surface of the Shixi wafer. / /, until the wafer boat is completely taken out of the furnace, the argon gas is continuously injected into the furnace. Thereby, the chlorine gas flowing out of the furnace can be packaged as a whole after the wafer boat is packaged, and the surface flatness of the above-mentioned stone wafer is maintained. When the boat is discharged from the bottom of the furnace, the opening portion from the bottom of the furnace is The flow rate of the argon gas flowing out is preferably 〇.〇 192 m/s or more. I9〇m/s or less. The gas flow rate in this range is suitable for protecting the surface of the wafer from the furnace by argon gas. When the gas flow rate is less than 0.0192m/s, it cannot be obtained by argon gas.充分The surface of the wafer is fully protected. The gas flow rate is particularly preferably 0·05 m/s or more. On the other hand, in the case where the above gas flow rate exceeds 0190 m/s, • even if the gas flow rate becomes large, it is not possible to obtain better. The present invention is more specifically described below based on the examples, but the present invention is not limited to the following embodiments. [Embodiment 1] First, the diameter is 8吋. 5。 The 结晶 (1〇〇) crystal ingot toward the <1〇〇> direction with a skewer of 0.03. The wafer was sliced to obtain a tantalum wafer and mirror-finished. The enamel wafer is placed on a boat and filled in a heat treatment in an argon atmosphere. The furnace was replaced with a hydrogen atmosphere at 700 ° C, and the temperature was raised, and maintained at llOOt: for 1 hour, and heat treatment was performed.仃 Thereafter, the temperature is lowered, and the argon atmosphere is placed in the furnace from the hydrogen atmosphere, and then the temperature is lowered until the silicon wafer is discharged from the furnace and the two gases are introduced into the furnace.守,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, The round is released. Ma 4:::2 Figure 9 shows the flow of the ambient gas and / dish in the above heat treatment step. = Side surface after treatment ‘Measure the surface relief image and surface roughness Rms of the area (4) and (4). Fig. 1 is a view showing a surface unevenness image of the second day of the second embodiment [Example 2] of the tantalum wafer obtained by AFM. - In addition to changing the heat treatment temperature · t to the sub-t, the heat treatment is carried out according to the condition of the first embodiment. , , - After treatment, the surface of the wafer is 'by surface roughness image and surface roughness Rms. Fig. 2 shows a surface uneven image of the Shishi wafer obtained by (iv) observation. 96149869 13 200835822 [Comparative Example i] The heat treatment temperature was 11 Torr. (3) The heat treatment of the tantalum wafer was carried out under the same conditions as in Example 1 except that the temperature was changed to 1 〇〇〇 ° C. For the surface of the tantalum wafer after heat treatment, the area of 3 // mx 3 / m was determined by Afm The surface unevenness image and the surface roughness Rms. Fig. 3 shows the surface unevenness image of the germanium wafer observed by AFM. It can be seen from the photographs of Figs. 1 to 3 that the heat treatment temperature is 1 〇〇 (^c) 1), the step-and-station structure is not formed on the surface of the wafer, and in the case where the heat treatment temperature is 11 〇〇 ° C or 12 〇〇 ° C (Examples 1, 2), the ladder is clearly confirmed. The surface roughness Rms is based on the heat treatment temperature of 丨〇〇〇. In the case of 〇 (Comparative Example 1), it is 0·158 nm, whereas in the case of 110 〇 π (0 047 nm under the example d) In the case of 1200 ° C (Example 2), it was 0·〇49 nm, and it was confirmed that the surface roughness was reduced at 1100 ° C or higher. Also, in the photograph of Fig. 1, the heat treatment temperature was 110 (rc). In the case of the case (Example 1), the line of the step of the ladder structure is directed to the upper right, and on the other hand, in the photo of Fig. 2, in the heat In the case where the temperature is set (Example 2), the step of the step and the structure of the step is the upper left side, because the direction in which the yaw angle is inclined is slightly different depending on the wafer. [Example 3] The surface unevenness image and the surface roughness Rms of the 3 μm x 3 /z dish region were measured by AFM on the surface of the tantalum wafer after heat treatment as in Example 2. Fig. 4 shows the surface uneven image of the tantalum wafer observed by AFM. In addition, the phenomenon that the result differs from that of Example 2 can be considered to be due only to the individual difference of the crystal 96149869 14 200835822. [Example 4] Two argon gases are used, and the rest are in accordance with Example 3
夕十：熱處理後之矽晶圓表面，藉afm測定 域之表面凹凸像及表面粗度Rms。 「圖5表示由AFM觀察所得之矽晶圓的表面凹凸像。Xi X: After the heat treatment, the surface of the wafer was measured by the afm surface roughness image and the surface roughness Rms. "Figure 5 shows the surface unevenness image of the germanium wafer observed by AFM.
U匕較例2] 環产、，、鱼’皿刖在700 c下將爐内自氮氣環境置換為氫氣 <兄亚進仃熱處理，於降溫後在70(rc下將爐内自氫 兄置換為氮氣環境以外，其餘依與實施例3相同的條件: 進行熱處理。 針^熱處理後之石夕晶圓表面，藉週測定3靖^區 域之表面凹凸像及表面粗度Rms。 圖6表示自AFM觀察所得之石夕晶圓的表面凹凸像。 ⑩[比較例3] 於升溫前在7〇〇。(:下將爐㈣減環境置換為氯氣 亚進行熱處理，於降溫後在70(rc下將爐内自氬氣環 ^置換為氮氣環境以外，其餘依與實施例3相同的條T， 進行熱處理。 ’ • 針對熱處理後之矽晶圓表面，藉AFM測定3/Zinx3^m區 - 域之表面凹凸像及表面粗度Rms。 时 圖7表示由AFM觀察所得之矽晶圓的表面凹凸像。 由圖4〜7之照片可知，在氫氣環境下的熱處理中，由於 96149869 15 200835822 體而表面之階梯•台構造大為不同，在將置換氣體 • 氬的情況（實施例3)下，階梯線成波狀’在將置換氣 •粗没為氮的情況（比較例2)下，階梯線為齒狀。 另士外，於氬氣環境下之熱處理中，在將置換氣體設為氮 虱氣）的情況（實施例4)下，階梯線為波狀，在設為 鼠的情況(比較例3)下，觀察到階梯線具有鋸齒狀與波狀 之中間形狀的階梯•台構造。 =卜’圖8表示由圖4〜7之照片所測定之表 _ 胃的比較圖表。 表面粗度Rms係於氫氣環境下之熱處理中， ，情__2)下為_，在氬氣置換的情二= 例3)下為0.054nm，又，在氬氣環境下之熱處理中，在氮 ^換的情況（比較例3)下為U62nm’在氬氣置換（常時 鼠氣）的情況（實施例4)為〇· 〇54nm。 由於階梯•台形狀因置換氣體而異，故表面粗度亦不 #同，確認藉由將既定溫度下之置換氣體設為氬，則可將表 面粗度Rms減低至〇· 〇6nm以下。 另外’將降溫時之爐内環境進行置換時的溫度，係於上 述實施例及比較例中均設為70(rc，但確認到即使在設為 500°C的情況下，亦可得到同等效果。 . -[實施例5 ] 依與實施例3相同之條件，進行熱處理後，予以降、攻， 於7〇rc下將爐内自氫氣環境置換為氬氣環境。- 置換完成後，在晶舟出爐時使爐底部開口部之流出氣體 96149869 16 200835822 流速進行變化，依各氣體速度分別測定經出爐之石夕晶圓的 表面粗度Rms。 圖10表示爐底部開口部之流出氣體流速與矽晶圓表面 粗度之關係的圖。 i 另外，上述實施例1〜4所示之表面粗度之值的差異，可 認為僅因晶圓個體差所致。 [比較例4 ] 依與實施例3相同之條件，進行熱處理後，予以降溫， 於7〇〇°C下將爐内自氫氣環境置換為氮氣環境。 现 置換完成後，在晶舟出爐時使爐底部開口部之流出氣體 流速變化，依各氣體流速分別測定經出爐之矽晶圓的表面 粗度Rms。 圖10表示將爐底部開口部之流出氣體流速與矽晶圓表 面粗度之關係與實施例5合併的圖。 ^ 由圖10所示之圖表可知，矽晶圓出爐時之爐内環境 ⑩中，氬氣（實施例5)較氮氣（比較例4)更能維持矽晶圓^ 表面平坦度，又，較佳係在將矽晶圓自爐取出為止，持續 將氬氣導入至爐内。 只 上述實施例及比較例中，為了更明確地顯示表面粗度的 減低效果與表面構造的不同，而使用依小至〇 〇3。之偏角 •所切片的矽晶圓，但本發明並不限制偏角大小，即使在增 ，大偏角的情況下，亦可得到矽晶圓之表面粗度減低效果。 【圖式簡單說明】 圖1為實施例1中矽晶圓表面（3 # mx3 // m)之AFM像照 96149869 17 200835822 片。 圖2為實施例2中石夕晶圓表面（3从mx3 // m)之人罗腿像照 片。 圖3為比較例1中石夕晶圓表面（3 // mx3 // m)之AFM像照 片。 圖4為實施例3中矽晶圓表面（3// .3#約之AF1像照 片0 片 片 圖5為實施例4中矽晶圓表面（3//mx3//m)之AFM像照 〇 圖6為比較例2中矽晶圓表面（3ymx3/zm)之ΑΜ像照 片 圖7為比較例3中矽晶圓表面（3vmx3vm)2 AFM像照 圖為圖4 7之AFM像照片中之各表面粗度Rms的圖表。 圖9為用於說明實施例中之熱處理步驟的流程圖。 、兄二針對矽晶圓出爐時之爐内環境為氬氣的情 4) ^ 々丨l出氣體流逮鱼石々a同主 、切日日S]表面粗度之關係。 96149869 18U匕Comparative example 2] The ring, the fish, the dish, and the fish in the furnace at 700 c, the furnace is replaced by hydrogen gas in the furnace. The heat treatment is carried out in the furnace. After cooling, the furnace is self-hydrogenated at 70 (rc). The surface was replaced by a nitrogen atmosphere, and the same conditions as in Example 3 were carried out: heat treatment was performed. The surface of the wafer was subjected to heat treatment, and the surface unevenness image and surface roughness Rms of the area were measured by the week. The surface unevenness image of the Shishi wafer obtained from AFM. 10 [Comparative Example 3] 7 〇〇 before the temperature rise. (: The furnace (4) was replaced with chlorine gas for heat treatment, and after cooling, at 70 (rc) In the furnace, the argon gas ring was replaced with a nitrogen atmosphere, and the other strip T was heat treated according to the same strip as in Example 3. ' • For the surface of the wafer after heat treatment, the 3/Zinx3^m area was measured by AFM- The surface unevenness image and surface roughness Rms of the domain. Fig. 7 shows the surface unevenness image of the germanium wafer observed by AFM. It can be seen from the photographs of Figs. 4 to 7 that in the heat treatment under a hydrogen atmosphere, due to the 96194869 15 200835822 The surface of the ladder and the structure of the platform are very different, in the replacement gas • In the case of argon (Example 3), the step line is wavy. In the case where the replacement gas and the coarse gas are not nitrogen (Comparative Example 2), the step line is toothed. In addition, under the argon atmosphere In the case of the heat treatment, in the case where the replacement gas is nitrogen helium gas (Example 4), the step line is wavy, and in the case of the mouse (Comparative Example 3), the step line is observed to have a zigzag shape and a wave. Step-to-station structure of the middle shape of the shape. Fig. 8 shows a comparison chart of the table _ stomach measured by the photographs of Figs. 4 to 7. The surface roughness Rms is in the heat treatment under a hydrogen atmosphere, and __2 The lower is _, which is 0.054 nm under the argon replacement II = Example 3), and in the heat treatment under argon atmosphere, in the case of nitrogen exchange (Comparative Example 3), U62nm' in argon The case of replacement (normally rat) (Example 4) was 〇·〇54 nm. Since the shape of the step and the table varies depending on the gas to be replaced, the surface roughness is not the same. It is confirmed that the surface roughness Rms can be reduced to 〇·〇6 nm or less by setting the replacement gas at a predetermined temperature to argon. In addition, the temperature at the time of replacing the furnace environment at the time of the temperature reduction was 70 (rc) in the above examples and comparative examples, but it was confirmed that the same effect can be obtained even when the temperature is set to 500 °C. - [Example 5] After the heat treatment was carried out under the same conditions as in Example 3, the furnace was lowered and attacked, and the furnace was replaced with an argon atmosphere at 7 〇 rc. - After completion of the replacement, in the crystal When the boat is discharged, the flow rate of the effluent gas at the bottom of the furnace is changed to 96149869 16 200835822, and the surface roughness Rms of the glazed wafer is measured according to each gas velocity. Fig. 10 shows the flow velocity of the effluent gas at the opening of the furnace bottom and 矽A graph showing the relationship between the surface roughness of the wafer. i In addition, the difference in the values of the surface roughness shown in the above embodiments 1 to 4 can be considered to be due only to the individual difference in the wafer. [Comparative Example 4] 3 After the same conditions, the heat treatment is carried out, and the temperature is lowered, and the atmosphere in the furnace is replaced with a nitrogen atmosphere at 7 ° C. After the completion of the replacement, the flow rate of the effluent gas at the opening of the bottom of the furnace is changed when the boat is discharged. According to each gas The surface roughness Rms of the wafer after firing was measured separately. Fig. 10 is a view showing a relationship between the flow velocity of the outflow gas in the opening portion of the furnace bottom and the surface roughness of the crucible wafer in the fifth embodiment. As can be seen from the graph, in the furnace environment 10 when the wafer is baked, argon gas (Example 5) can maintain the flatness of the surface of the tantalum wafer more than nitrogen (Comparative Example 4), and preferably, it is twinned. Argon gas was continuously introduced into the furnace until the cylinder was taken out from the furnace. In the above-described examples and comparative examples, in order to more clearly show the effect of reducing the surface roughness and the surface structure, the use was as small as 〇〇3. Deflection angle • The sliced germanium wafer, but the present invention does not limit the size of the declination. Even in the case of increasing or large declination, the surface roughness reduction effect of the crucible wafer can be obtained. 1 is an AFM image of the surface of the wafer (3 # mx3 // m) in the first embodiment, and is shown in the image of the image of the image of the surface of the wafer (3 from mx3 // m). The leg is like a photo. Figure 3 is the AFM image of the surface of the Shixi wafer (3 // mx3 // m) in Comparative Example 1. Figure 4 is the surface of the tantalum wafer in Example 3 (3//3# about AF1 image photo 0 sheet Figure 5 is the AFM of the wafer surface (3//mx3//m) in Example 4 Fig. 6 is a photograph of the surface of the tantalum wafer (3ymx3/zm) in Comparative Example 2. Fig. 7 is a photograph of the surface of the tantalum wafer (3vmx3vm) in Comparative Example 3, and the AFM image is the AFM image of Fig. 47. Fig. 9 is a flow chart for explaining the heat treatment step in the embodiment. The brother 2 is for the case where the furnace environment is argon when the wafer is discharged 4) ^ 々丨l The relationship between the gas flow and the surface roughness of the fish and stone. 96149869 18