201224230 六、發明說明： 【發明所屬之技術領域】 本發明係關於生長晶體之領域，及更特定言之係關於用 於生長大、高純度晶體（例如藍寳石）之方法及系統。 本申請案係共同待審的2011年4月27曰申請之美國非臨 時專利申請案第13/095,073號及2010年10月21曰申請之美 國非臨時專利申請案第12/909,471號之部分接續申請案， 二者皆係2009年1〇月22曰申請，公開申請案號us 2〇1〇_ 0101387之共同待審的美國非臨時專利申請案第12/588,656 號之部分接續申請案。美國非臨時專利申請案第 12/588,656號根據35 U.S.C. 119主張2008年10月24日申請 之美國臨時申請案第61/1〇8,213號之優先權。將所有上述 申請案以引用全文之方式併入本文中。 【先前技術】 在許多高溫材料處理應用中，使材料於坩堝中熔化至高 於該材料熔點之溫度。典型地，該坩堝係於爐内由支撐物 (諸如轴）支撐，且該坩堝及軸二者皆由耐火材料（諸如耐火 金屬）形成。通常此等加工應用涉及大量熔融材料。如此 大量，加上該坩堝本身之重量，會導致在該坩堝與其支撐 物間之接觸區域處之高負載。此外，製造循環的時間會延 長’因此需要延長該轴及坩堝之暴露於高溫。在延長的高 溫及負載條件下，該轴及坩堝之接觸表面具有融合在一起 之不良趨勢。此外，存在於該轴及坩堝之接觸表面上的任 何污染物會惡化該問題。需要沒有上述問題之用於高溫加 159567.doc 201224230 工應用的系統及方法β 【發明内容】 在一態樣中’本發明係關於用於高溫材料加工之系統。 該系統包括掛堝、適以支撐該坩堝之軸及在該坩堝及該軸 之間的中間材料。該中間材料係直接施覆於該坩堝及該軸 之接觸表面的圓盤或塗層。 在另一態樣中’本發明係關於用於生長晶體之系統。該 系統包括坩堝，至少一個適以加熱該坩堝之加熱元件，適 以接受冷卻劑流體以冷卻一部分該坩堝之晶種冷卻組件， 在該坩堝及該晶種冷卻組件之間的中間材料，包含熱絕緣 及適以改變該坩堝内溫度梯度的梯度控制裝置，及實質上 環繞該掛禍的絕緣元件’加熱元件及梯度控制裝置。該梯 度控制裝置及該坩堝係可相對於彼此及該至少一個加熱元 件獨立地移動。 在又另一態樣中’本發明係關於生長晶體之方法。該方 法包括在掛堝中大體上完全覆蓋裝載材料中的晶種，使用 熱源來溶化該裝載材料，使冷卻流體流過與該堆禍熱連通 之晶種冷卻組件以在該裝載材料熔化時保持該晶種至少部 分完整，使至少一部分該晶種熔化成熔融的裝載材料，藉 由降低該熱源之溫度連續生長該晶體，使該熔融的裝載材 料及晶種自該熱源移動，提高該晶種之冷卻速率，及改變 該坩堝内的溫度梯度。該方法進一步包括先在該坩堝與該 晶種冷卻組件之間提供中間材料，該中間材料含有直接施 覆於該时瑪及S亥晶種冷卻組件之接觸表面的圓盤或塗層， 159567.doc 201224230 然後再使用熱源來熔化該裝載材料。 在又另-態樣中，本發明係關於詩高溫材料處理之方 法。該方法包括在溶化褒載材料之前，在轴及由該軸支標 之掛禍之間提供中間材料，間材料為直接施覆於該掛 堝之接觸表面之圓盤或塗層。 【實施方式】 文中參照圖式描述多種較佳實施例。 本發明描述在軸與坩堝之間使用中間材料（諸如圓盤及/ 或塗層）以便於分離。此等中間材料適用於希望阻止坩堝 與支撐轴之間融合的材料加工應用》此等應用典型地係掛 禍及支撐軸彼此高負載接觸之高溫應用。此等應用包括 (但不限於）晶體生長、定向固化、鑄件及鑄造應用。無意 受限於任何特定應用，本發明描述針對CHES晶體生長爐 使用此種中間材料’該等CHES晶體生長爐描述於美國專 利申請案號 13/095,073、12/909,471、12/588,656 及 61/108,213中’每一者之全體内容係以引用之方式併入本 文中。 圖1為本發明之晶體生長系統及方法之一實施例中使用 的爐100之截面圖。在圖1中，該爐100可包括殼丨05。該殼 105可包括外殼部分110及地板115。該外殼部分110及該地 板115—起形成腔室，其在某些實施例中可為雙層壁、水 冷卻室。該爐100亦可包括絕緣元件130、晶種冷卻組件 120、至少一個加熱元件125、梯度控制裝置（GCD) 13 5及坩 堝150，其等全部係封閉於該外殼部分110中。該等封閉於 該外殼部分110中的元件形成「加熱區」。因此，該加熱元 159567.doc 201224230 件125、坩堝150、梯度控制裝置135、絕緣元件13〇及一部 分該晶種冷卻組件120全部係該加熱區之部分。於本申請 案通篇中提及該加熱區、該熔體、該爐及該腔室可（如上 下文指示）係指該腔室之室内部分。 該絕緣元件130實質上環繞該晶種冷卻組件12〇、該（等） 加熱元件125及該坩堝150及使在該絕緣元件外部的熱轉移 最小化。該絕緣元件130可由石墨材料、高溫陶瓷材料、 耐火金屬或耐火金屬之合金製成。 該（等）加熱元件125實質上環繞該晶種冷卻組件12〇及該 堆禍150並適以加熱該掛瑪150 ^該加熱元件可包括石墨或 耐火金屬（諸如鈕、鉬或鎢）或耐火金屬之合金。該（萼）加 熱元件125在晶體生長期間適於實質上緩慢地降低該腔室 之加熱區内的溫度’（例如）以〇 〇2〇c /心之低速。 該坩堝150盛裝晶種140(例如，d形、圓形等）及裝載材 料145(例如，藍寶石（Al2〇3)、矽（Si)、氟化鈣（以^)、碘 化鈉（Nal)及其他鹵族鹽晶體）。該坩堝15〇可由耐火金屬 (諸如鉬、鎢或其合金）或非金屬材料（諸如石墨（c)、氮化 棚（BN)及其類似物）製成。在該掛塥為鎢之實施例中該 坩堝可在後續操作中再使用。此坩堝比其他坩堝（諸如鉬 坩堝）節約成本，該等其他坩堝在高溫晶體生長應用（如藍 寶石生長）中典型地係一次性使用坩堝。在一些實施例 中，該坩堝150可盛裝〇.3至450千克之該裝載材料145。 該坩堝150可包括晶種接收區域21〇(示於圖2)。該晶種 接收區域210在該坩堝150中盛裝該晶種14〇。在圖2顯示之 159567.doc 201224230 實施例中，S亥晶種接收區域僅為在圓柱形坩堝之平底處的 -個區域。然而’豸晶種接收區域可含有輪廓。例如，該 晶種接收區域可為圓錐形或可含有種袋。該晶種接收區域 可適於以特定取向安裝特定大小及形狀之晶種。 在圖1顯示之實施例中，該坩堝150係由該晶種冷卻組件 120支撐且可相對於該（等）加熱元件125移動。該坩堝係 可藉由该可上升及下降之晶種冷卻組件丨2〇移動。該晶種 冷卻組件120係穿過該殼1〇5之地板丨15中的一或多個開口 移動。如以下進一步詳細描述，在該晶體生長階段期間經 由该晶種冷卻組件降低該坩堝有助於維持晶體生長速率並 促進生長實質上更大之晶體。 如圖1之實施例中顯示’該晶種冷卻組件丨2〇可為中空組 件（例如，由对火金屬，諸如鎢（w)、钥（M〇) '鈮（Nb)、鑭 (La)、钽（Ta)、銖（Re)或其等合金製成），其支撐並與該掛 禍15 0之底部熱連通。該晶種冷卻組件ι2〇亦接收冷卻流體 155(例如氦（He)、氖（Ne)及氫（H))，以通過該中空部分冷 卻該坩堝150之支撐部分。可控制該冷卻流體進入該晶種 冷卻組件之流動速率，以調整該晶種之冷卻速率。 ，说CHES爐内之藍寶石生長而言’裝載料被溶化至高於 藍寶石熔點（2050°C )之溫度，因此該坩堝及該晶種冷卻組 件之軸皆係由耐火金屬（諸如鉬、鶴或鉬及嫣之合金）製 成。在某些實施例中’該晶種冷卻組件120及該坩禍15〇皆 由鶴製成。因此，更容易在該晶種冷卻la件及时禍之間轉 移熱量及質量。該藍寶石晶體之生長循環可能耗時數週， 159567.doc 201224230 因此該軸及坩堝需要長期暴露於高溫。此外，該坩堝内裝 載材料及該坩堝本身之重量導致在該坩堝及該軸之間之大 量負載。在延長的咼溫及負載條件下，該軸及掛禍之接觸 表面（即，該轴及坩堝彼此接觸之表面）具有融合在一起之 不良趨勢。此外，在該軸及坩堝之接觸表面上任何污染物 之存在會惡化該問題。 可藉由在該軸及該坩堝之間引入中間材料來阻止該坩堝 及軸之間的融合。該中間材料可為置於該軸及坩堝之接觸 表面之間的圓盤。在另一實施例中，該中間材料為具有經 塗覆表面的圓盤。或者，該中間材料可為直接施覆於該軸 及掛禍之接觸表面的塗層。 如圖6中所示’該中間材料為圓盤11〇5，其阻止該晶種 冷卻組件120及該坩堝150之舞觸表面之間的直接接觸。該 圓盤1105係用作中間材料，其阻止晶種冷卻組件1及該 坩堝150之間的融合。在一實施例中，該圓盤為耐火材料 (諸如鉬、鎢或其合金）之薄層，其位於該晶種冷卻組件12〇 及坩堝150之間。該圓盤之厚度可係大約1 mm或更大。 在另一實施例中，該圓盤經塗覆以進一步阻止融合。合 適之塗層包括碳化物、氮化物、氧化物、矽化物或硼化 物。合適之碳化物包括（例如）碳化鈦。氮化物包括（例如） 氮化矽、氮化硼及氮化鈦。矽化物包括（例如）矽化鉬，及 硼化物包括（例如）硼化鍅。在其他實施例中，該塗層可包 括諸如氧化錫、氧化餌、氧化釓、氧化鋁、氧化釔、氧化 錯或經氧化紀穩定之氧化錯的氧化物。該塗層可藉由嗔 159567.doc 201224230 塗或漆塗施覆’並較佳在乾燥後具有介於約〇 1 mm及約 1 · 0 mm間之厚度。 或者’該中間材料可為上述碳化物、I化物、氧化物、 矽化物或硼化物之塗層，其係直接施覆於該軸及坩堝之接 觸表面。該塗層可為混合物，諸如包括一或多種上述化合 物之懸洋液或漿液。在—實施例中，該塗層為含有氧化紀 粉末之漿液。該混合物可為基於水，基於酵（諸如乙醇）或 其他溶劑（諸如丙酮）。在—實例中，該混合物包含約娜 及約60%之間之氧化纪（以重量計）。該塗層可（例如）藉由喷 塗或漆塗施覆於該等接觸表面，並較佳在乾燥後具有介於 約0·1麵及約1·〇_間之厚度。該塗層可在進行每次晶體 生長之前施覆。較佳地，在每次施覆該塗層之前清潔該晶 種冷卻組件軸及坩堝之接觸表面。 如上述使用該等圓盤及/或塗層以利於該軸及坩堝之間 的分離並不限於應用在C聰爐中。此等中間材料亦可用 於其他需要在㈣及支撐軸之間阻止融合的材料處理應 用諸如晶體生長、定向固化、轉件及緯造應用。例如， 該等中間材料可適用於verticalBridgmaI^。該抽無需為 晶種冷卻組件’即該轴可不提供自該掛禍之底部的顯著敎 移除，而係可僅提供對該掛禍之物理支撐。因此，該系統 可包括掛禍、適以支撐該掛禍之轴、及在該堆瑪及該轴之 間:中間材料’該令間材料包括直接施覆於該掛禍及該軸 之接觸表面的圓盤或塗層。 該梯度控制裝置（GCD)135改變在不同操作階段期間該 159567.doc 201224230 坩堝内的熔體及/或晶體之溫度梯度。可調整該GCD之位 置以控制接近該坩堝底部（即，該晶種附近）的熱傳程度， 從而提供視需要改變溫度之能力。該GCD包含熱絕緣。該 熱絕緣可包含耐火金屬，諸如鎢或鉬，或可由石墨氈形 成。在一些實施例中，該GCD之絕緣包括輻射防護罩。每 一幅射防護罩可由耐火金屬（諸如鎢或鉬或其合金）形成。 在一實施例中，至少一個輻射防護罩係由鎢形成。在另一 實施例中，最内部的輻射防護罩（即，最接近該坩堝之防 護罩）係由鎢形成，而最外部的輻射防護罩（即，離該坩堝 最遠之防護罩）係由鉬組成。該等輻射防護罩可堆疊在一 起並用由與該等防護罩相同之材料形成的隔片間隔開。 在圖1中顯示之實施例巾，該GCD可相對於該晶種冷卻 組件120、該（等）加熱元件125、該絕緣元件13〇及該坩堝 150在疋位置範圍内移動。該GCD及該坩堝15〇亦可相對 於彼此獨立地移動。該GCD之移動性使其可控制自該坩堝 底部附近的熱傳程度’從而視需要改變該坩堝内容物（例 如，生長中之晶體及熔體）的溫度梯度。在圖丨顯示之實施 中’該GCD可沿著該晶種冷卻組件軸移動。在圖i顯示之 實施例中該GCD之熱防護罩包括開〇，以允許該gcd沿 著該晶種冷卻組件之轴移動。該GCD位於該轴上越高其 越接近該加熱元件。在-高處位置，諸如圖！中顯示者， 該GCD使該坩堝之底部附近與晶種隔絕。隨著該GCD自該 加熱元件125移得更遠，該坩堝之底部附近的熱量可被消 散且'°著該掛碼之溫度梯度增加。由該GCD達成的溫度 159567.doc 201224230 梯度的增加説明於圖7。該圖顯示在本發明系統中沿坩堝 高度的兩條溫度梯度曲線。右邊的曲線表示當gcd在高處 位置時沿該掛竭之溫度梯度’而左邊的曲線表示當G⑶在 低處位置時之溫度梯度。在高處位置沿該㈣高度之溫度 梯度為Μ。將該GCD置於低處位置導致沿該^之= 的溫度梯度’ ΛΤ2。在晶體生長之不同階段期間需要不同 之溫度梯度’降低的梯度有助於確保所有裝 載料熔化且該熔體之溫度係盡可能地均勻。在該晶體之： 長期間，Μ增加之梯度確保“亥晶種至該熔體頂部之受押 晶體生長。在該晶體之退火期間，典型上更需要減小之= 度梯度1此’在晶體生長期間降低該GCD及在熔融及退 火期間升高該GCD可獲得高品質之更大單晶。 圖5為依據一實施例使用該爐1〇〇(例如圖丨中顯示者）環 繞c轴生長單晶及其後使用料晶生産晶圓之示例性方法 的方法流程圖5〇〇。 在步驟505中，將晶種（例如，藍寶石晶種）置於該掛禍 之底部，例如，在該晶種接收區域21〇中（如圖2中顯 不）。在步驟510中，將裝載材料（例如，藍寶石裝載材料） 置於該賴15〇中，以使該晶種⑽實質上完全為該裝載材 料14所覆蓋（如圖2中顯示）。接著，將具有該裝載㈣及該 晶種的坩堝150裝入該爐10〇中。 在步驟515中，提供能量至該加熱元件125以加熱該坩堝 150中的裝載材料145及晶種14〇至實質上稠高於該裝載材 料145之熔化溫度。例如，就藍寶石裝載材料而言，可在 159567.doc -11· 201224230 約2040至2100°C之範圍由‘ & # “ 靶固内加熱該坩堝。此時可提高及/或 保持該坩堝在高處位置。可提高及/或保持該GCD在高處 位置以最小化該溫度梯度並確保均句的炫體。—旦該裝載 材料145完全熔化’則使該熔化的裝載材料(亦稱爲該裝載 材料之「熔體」）保持預定量的時間以達均一化典型地 係1-24小時。 在步驟520中’可藉由在步驟515中加熱該裝載材料145 之同時使該冷卻流體155流動通過該晶種冷卻組件12〇來冷 卻該堆禍150之底部及晶種刚。在一些實施例中當該裝 載材料之㈣係高於該熔化溫度時，使用氦來冷卻該_ 150之底部及晶種14〇。例如，可使氦氣以大約在約至 100 —範圍内之速率流經支樓㈣禍15〇之底部的晶種冷 卻組件120。允許至少一部分該晶種溶化到該炫融裝載材 料中，並冷卻該坩堝150之底部以使該晶種14〇保持完整且 未完全熔化。在晶種沿(:軸取向的情況中，最小所需熔化 可包括熔化-部分該晶種之頂面（例如，⑼）以形成凸狀晶 體生長表面（如圖3中顯示）。藉由提高該熔體之溫度及/或 減小氦氣通過該晶種冷卻組件2〇1之流動速率（例如，自 lpm至80 lpm)來熔化一小部分該晶種14〇之頂面，形成凸 面（或圓頂）形晶體。該凸狀晶體生長表面為具有由不同取 向組成之多重階梯的真實非習慣面（例如，非該真^^面）。該 凸狀晶體生長表面有助於穩定實質上沿£軸之晶體生長過 程0 在步驟525中，開始晶體之生長（步驟525)。在—或多個 159567.doc 12 201224230 實施例中’隨著晶體生長，藉由使通過該晶種冷卻組件 120之該冷卻流體155的流動速率緩升而逐漸提高該坩堝 150底部之冷卻速率。例如，可在24_96之時段内使氦氣之 流動速率提高至600 lpm。同時，可藉由實質上緩慢降低 該（等）加熱元件125之溫度（例如以約〇 〇2_丨〇°c /小時之速 率）來貫質上降低該溶體之溫度。因此，該溶體被冷卻且 在該晶種與該熔體之間形成溫度梯度。可實質上地提高該 溫度梯度以確保該晶體之持續受控生長並產出更大的固化 單晶。此係藉由在晶體生長期間降低該GCD 135及/或保持 該GCD處於低處位置而完成。降低該gcd提高自該晶種附 近之熱轉移速率，從而增加沿該生長中晶體及熔體之溫度 梯度。例如，該GCD可以約〇. 1-5 mm/小時之速率降低。 另外’隨著該晶體長高，自該坩禍底部起的固-液等溫 線之距離增大且該冷卻流體15 5之作用減小，導致該晶體 之生長速率平穩減慢。為補償該晶體之減小的生長速率， 可藉由移動該晶種冷卻組件120來降低該掛禍15〇。降低該 坩堝將增加該坩堝及該加熱元件之間的距離，從而使得該 溶體冷卻並保持該晶體之生長速率。在一實施例中，該掛 禍係以約0.1 -5 mm/小時之速率降低。 當該晶體生長完成後，使該固化晶體經歷退火步驟，其 中在使該晶體冷卻至室溫以前，使該晶體保持在低於該晶 體之熔化溫度的特定溫度歷時特定量的時間。例如，使該 加熱元件保持在低於該晶體材料之熔點約50_200。(：範圍内 之溫度歷時足以在整個該晶體達成溫度均一性的時段。此 J59567.doc 13 201224230 可藉由降低該（等）加熱元件125之溫度，減少該冷卻流體 155之流動以減緩自該坩堝15〇之底部移除熱量，並移動該 GCD 135至有利位置以減小溫度梯度來達成。例如，可以 約0.02至50C /小時之速率降低該加熱元件之溫度並可在退 火階段期間提高該GCD以減小該溫度梯度，從而使該固化 b曰體達到更均勻之溫度。此外，在退火階段期間可將該掛 禍提南或保持在晶體生長位置，以確保該固化單晶在冷卻 之前退火。 在退火後，逐漸降低該爐100之溫度以逐漸並均勻地冷 卻該經退火晶體至室溫。此時該GCD及坩堝皆可保持在退 火位置或可降低。可進一步降低冷卻流體至該晶種冷卻組 件之速率，或可保持該退火速率。此外，可在自該爐 中取出該晶體之前增加該爐1 〇〇内的惰性氣體壓力。 在步驟530中，在完成該晶體生長後，自該坩堝15〇取出 該晶體。在步驟535中，將該取出的晶體取芯以產生實質 上圓柱形的晶錠。在一實施例中，藉由實質上垂直於該取 出晶體之頂面取芯而產出該圓柱形晶錠（如圖4中所示卜在 步驟540中，將該經取芯的圓柱形晶錠切片以產出晶圓。 應注意，雖然圖5描述示例性方法之步驟，但在替代性實 施例中，熟悉此項技術者應瞭解，可改變或省略某些步 驟’可調整步驟順序’或可包含額外步驟。此等額：；驟 可包括將該腔室抽真空，用氣體（諸如氬氣或其類似物）回 填該腔室。 如以上描述’在該方法之各種階段期間，可操控該加熱 I59567.doc •14· 201224230 元件12 5之溫度、該掛渦15 0之位置、該晶種冷卻組件中冷 卻流體之流動速率、及該GCD 135之位置，以優化固體單 晶之生產。其一實例闡述於圖8，其概述在本發明之一實 施例中在各種階段期間此等參數之狀態。 雖然本實施例已參照特定示範實施例描述，但當明瞭可 在不脫離各種不同實施例之更寬精神及範圍下，對此等實 施例進行各種修改及變化。此外，當明瞭本文揭示之各種 不同操作、製程及方法可以任何順序進行。因此，應將該 説明書及圖式視為闡述意義’而非限制意義。 【圖式簡單說明】 圖1為依據一實施例，用於沿〇軸生長單晶之爐之截面 圖； 圖2至4闡述依據一貫施例自晶種形成經取芯c_軸圓柱形 晶錠之方法； 圖5為依據一實施例，使用爐（例如圖丨中顯示者）環繞c_ 轴生長單晶其後使用料晶產出晶圓之某些步驟之示 例性方法的方法流程圖； 圖6說月依據本發明之—實施例在晶體生長系統之晶種 冷卻軸與坩堝之間的中間材料； 圖7為兩不同溫度梯度之圖形表示；及 圖8為概述在本發明之—實施例之各操作階段期間各種 參數之狀態的表。 【主要元件符號說明】 159567.doc 15- 201224230 100 爐 105 殼 110 外殼部分 115 地板 120 晶種冷卻組件 125 加熱元件 130 絕緣元件 135 梯度控制裝置 140 晶種 145 裝載材料 150 掛禍 155 冷卻流體 210 晶種接收區域 310 凸形晶體生長表面 320 熔體表面 1105 圓盤 159567.doc •16-201224230 VI. Description of the Invention: [Technical Field of the Invention] The present invention relates to the field of growing crystals, and more particularly to methods and systems for growing large, high purity crystals such as sapphire. This application is a continuation of the continuation of the US non-provisional patent application No. 13/095,073, filed on April 27, 2011, and the US non-provisional patent application No. 12/909,471, filed on October 21, 2010. The application is a part of the continuation application of US copending US Non-Provisional Patent Application No. 12/588,656, filed on January 22, 2009. U.S. Provisional Patent Application Serial No. 61/588,656, filed on Jan. 24, 2008, which is incorporated herein by reference. All of the above applications are incorporated herein by reference in their entirety. [Prior Art] In many high temperature material processing applications, the material is melted in a crucible to a temperature above the melting point of the material. Typically, the tantalum is supported in a furnace by a support such as a shaft, and both the shaft and the shaft are formed of a refractory material such as a refractory metal. Often such processing applications involve a large amount of molten material. Such a large amount, plus the weight of the crucible itself, results in a high load at the contact area between the crucible and its support. In addition, the manufacturing cycle time will be extended. Therefore, it is necessary to extend the exposure of the shaft and the crucible to high temperatures. Under extended high temperature and load conditions, the contact surfaces of the shaft and the crucible have a tendency to fuse together. In addition, any contaminants present on the contact surfaces of the shaft and the crucible can exacerbate the problem. There is a need for a system and method for high temperature application 159567.doc 201224230 application without the above problems. [Invention] In one aspect, the present invention relates to a system for processing high temperature materials. The system includes a shackle, a shaft adapted to support the raft, and an intermediate material between the raft and the shaft. The intermediate material is applied directly to the disc or coating of the crucible and the contact surface of the shaft. In another aspect, the invention relates to a system for growing crystals. The system includes a crucible, at least one heating element adapted to heat the crucible, adapted to receive a coolant fluid to cool a portion of the crucible seed cooling assembly, an intermediate material between the crucible and the seed cooling assembly, comprising heat Insulation and a gradient control device adapted to change the temperature gradient in the crucible, and an insulating element 'heating element and gradient control device substantially surrounding the hazard. The gradient control device and the tether are independently movable relative to each other and the at least one heating element. In yet another aspect, the invention relates to a method of growing crystals. The method includes substantially completely covering seed crystals in the loading material in the hanging file, using a heat source to dissolve the loading material, and flowing the cooling fluid through the seed crystal cooling assembly in thermal communication with the stack to maintain the material as it melts The seed crystal is at least partially intact, such that at least a portion of the seed crystal is melted into a molten loading material, the crystal is continuously grown by lowering the temperature of the heat source, and the molten loading material and seed crystal are moved from the heat source to increase the seed crystal. The rate of cooling, and the temperature gradient within the crucible. The method further includes first providing an intermediate material between the crucible and the seed cooling assembly, the intermediate material comprising a disc or coating applied directly to the contact surface of the hour and S-series cooling assembly, 159,567. Doc 201224230 Then use a heat source to melt the load material. In yet another aspect, the invention is directed to a method of processing poetic high temperature materials. The method includes providing an intermediate material between the shaft and the hazard from the shaft support prior to melting the load bearing material, the intervening material being a disc or coating applied directly to the contact surface of the hung. [Embodiment] Various preferred embodiments are described herein with reference to the drawings. The present invention describes the use of intermediate materials (such as disks and/or coatings) between the shaft and the crucible to facilitate separation. These intermediate materials are suitable for use in material processing applications where it is desirable to prevent fusion between the crucible and the support shaft. These applications are typically high temperature applications where the support shafts are in high load contact with each other. Such applications include, but are not limited to, crystal growth, directional solidification, casting, and foundry applications. Without intending to be limited to any particular application, the present invention describes the use of such intermediate materials for a CHES crystal growth furnace. These CHES crystal growth furnaces are described in U.S. Patent Application Serial Nos. 13/095,073, 12/909,471, 12/588,656 and 61/108,213. The entire contents of 'each of each' are incorporated herein by reference. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a cross-sectional view of a furnace 100 used in an embodiment of a crystal growth system and method of the present invention. In FIG. 1, the furnace 100 can include a casing 05. The housing 105 can include a housing portion 110 and a floor 115. The outer casing portion 110 and the floor plate 115 together form a chamber which, in some embodiments, may be a double wall, water cooling chamber. The furnace 100 may also include an insulating member 130, a seed cooling assembly 120, at least one heating element 125, gradient control devices (GCD) 135 and 埚 150, all of which are enclosed in the outer casing portion 110. The elements enclosed in the outer casing portion 110 form a "heating zone". Thus, the heating element 159567.doc 201224230 piece 125, crucible 150, gradient control device 135, insulating element 13A and a portion of the seed crystal cooling assembly 120 are all part of the heating zone. As mentioned throughout this application, the heating zone, the melt, the furnace and the chamber (as indicated below) refer to the interior portion of the chamber. The insulating element 130 substantially surrounds the seed cooling assembly 12, the heating element 125 and the crucible 150 and minimizes heat transfer outside of the insulating element. The insulating member 130 may be made of a graphite material, a high temperature ceramic material, a refractory metal or an alloy of a refractory metal. The heating element 125 substantially surrounds the seed cooling assembly 12 and the stack of defects 150 and is adapted to heat the pylon 150. The heating element may comprise graphite or a refractory metal (such as a button, molybdenum or tungsten) or fire resistant. Metal alloy. The (萼) heating element 125 is adapted to substantially slowly lower the temperature in the heating zone of the chamber during crystal growth [for example, to 低 2〇c / low speed of the heart. The crucible 150 contains a seed crystal 140 (eg, d-shaped, circular, etc.) and a loading material 145 (eg, sapphire (Al2〇3), bismuth (Si), calcium fluoride (with ^), sodium iodide (Nal) And other halogen salt crystals). The crucible may be made of a refractory metal such as molybdenum, tungsten or an alloy thereof or a non-metallic material such as graphite (c), nitride shed (BN) and the like. In the embodiment where the hook is tungsten, the crucible can be reused in subsequent operations. This is a cost savings over other crucibles, such as molybdenum crucibles, which are typically used once in high temperature crystal growth applications such as sapphire growth. In some embodiments, the crucible 150 can hold from 33 to 450 kg of the loading material 145. The crucible 150 can include a seed receiving area 21 (shown in Figure 2). The seed receiving area 210 holds the seed crystal 14 in the crucible 150. In the embodiment of 159,567.doc 201224230 shown in Figure 2, the S-seed receiving area is only an area at the flat bottom of the cylindrical crucible. However, the seed crystal receiving area may contain a contour. For example, the seed receiving area can be conical or can contain a seed bag. The seed receiving area can be adapted to mount a seed of a particular size and shape in a particular orientation. In the embodiment shown in FIG. 1, the crucible 150 is supported by the seed cooling assembly 120 and is movable relative to the (equal) heating element 125. The tether can be moved by the seed crystal cooling assembly 丨2〇 which can be raised and lowered. The seed cooling assembly 120 is moved through one or more openings in the floor raft 15 of the casing 1〇5. As described in further detail below, lowering the crucible by the seed cooling assembly during the crystal growth phase helps maintain crystal growth rates and promotes the growth of substantially larger crystals. As shown in the embodiment of FIG. 1 , the seed cooling assembly 丨 2 〇 may be a hollow component (for example, by a pair of fire metals such as tungsten (w), a key (M〇) '铌 (Nb), 镧 (La) , (Ta), Re (Re) or its alloys, etc., which support and are in thermal communication with the bottom of the smash. The seed cooling assembly ι2〇 also receives a cooling fluid 155 (e.g., helium (He), neon (Ne), and hydrogen (H)) to cool the support portion of the crucible 150 through the hollow portion. The flow rate of the cooling fluid into the seed cooling assembly can be controlled to adjust the cooling rate of the seed crystal. In the case of sapphire growth in the CHES furnace, the loading material is melted to a temperature higher than the melting point of sapphire (2050 ° C), so the axis of the crucible and the cooling element of the seed crystal is made of refractory metal (such as molybdenum, crane or molybdenum). Made of bismuth alloy. In some embodiments, the seed cooling assembly 120 and the crucible are made of a crane. Therefore, it is easier to transfer heat and mass between the seed crystal cooling and the timely failure. The growth cycle of the sapphire crystal can take several weeks, 159567.doc 201224230 Therefore the shaft and crucible need to be exposed to high temperatures for a long time. In addition, the load of the material in the crucible and the weight of the crucible itself results in a large load between the crucible and the shaft. Under extended temperature and load conditions, the contact surface of the shaft and the catastrophic surface (i.e., the surface where the shaft and the cymbal contact each other) have a tendency to fuse together. In addition, the presence of any contaminants on the contact surfaces of the shaft and the crucible can exacerbate the problem. The fusion between the crucible and the shaft can be prevented by introducing an intermediate material between the shaft and the crucible. The intermediate material can be a circular disc placed between the contact surfaces of the shaft and the crucible. In another embodiment, the intermediate material is a disk having a coated surface. Alternatively, the intermediate material may be a coating applied directly to the contact surface of the shaft and the catastrophe. As shown in Fig. 6, the intermediate material is a disk 11〇5 which prevents direct contact between the seed crystal cooling assembly 120 and the dance surface of the crucible 150. The disc 1105 serves as an intermediate material that prevents fusion between the seed crystal cooling assembly 1 and the crucible 150. In one embodiment, the disk is a thin layer of refractory material (such as molybdenum, tungsten or alloys thereof) between the seed crystal cooling assembly 12 and the crucible 150. The thickness of the disc can be about 1 mm or more. In another embodiment, the disc is coated to further prevent fusion. Suitable coatings include carbides, nitrides, oxides, tellurides or borides. Suitable carbides include, for example, titanium carbide. Nitrides include, for example, tantalum nitride, boron nitride, and titanium nitride. Tellurides include, for example, molybdenum telluride, and boride includes, for example, lanthanum boride. In other embodiments, the coating may comprise an oxide such as tin oxide, oxidized bait, cerium oxide, aluminum oxide, cerium oxide, oxidized or oxidized stabilized oxidized. The coating may be applied by coating or lacquering by 嗔 159567.doc 201224230 and preferably having a thickness of between about mm 1 mm and about 1 · 0 mm after drying. Alternatively, the intermediate material may be a coating of the above-described carbide, compound, oxide, telluride or boride which is applied directly to the contact surfaces of the shaft and the crucible. The coating can be a mixture, such as a suspension or slurry comprising one or more of the above compounds. In the embodiment, the coating is a slurry containing oxidized powder. The mixture can be water based, based on leaven (such as ethanol) or other solvent (such as acetone). In the example, the mixture comprises enamel and an oxidation number (by weight) between about 60%. The coating can be applied to the contact surfaces, for example, by spraying or lacquering, and preferably has a thickness of between about 0.1 mm and about 1 Å after drying. The coating can be applied before each crystal growth is performed. Preferably, the seed cooling assembly shaft and the contact surface of the crucible are cleaned prior to each application of the coating. The use of such discs and/or coatings as described above to facilitate separation between the shaft and the crucible is not limited to application in C-cylinders. These intermediate materials can also be used in other material processing applications such as crystal growth, directional solidification, transfer and weft applications where it is desirable to prevent fusion between (4) and the support shaft. For example, the intermediate materials can be applied to verticalBridgmaI^. The pumping need not be a seed cooling assembly', i.e., the shaft may not provide significant 敎 removal from the bottom of the smash, but may only provide physical support for the smash. Thus, the system can include a hazard, a shaft adapted to support the hazard, and between the stack and the shaft: the intermediate material 'the inter-material material includes a direct application to the contact surface of the hazard and the shaft Disc or coating. The gradient control device (GCD) 135 changes the temperature gradient of the melt and/or crystal within the 159567.doc 201224230 crucible during different stages of operation. The location of the GCD can be adjusted to control the degree of heat transfer near the bottom of the crucible (i.e., near the seed crystal) to provide the ability to change temperature as needed. The GCD contains thermal insulation. The thermal insulation may comprise a refractory metal such as tungsten or molybdenum or may be formed from a graphite felt. In some embodiments, the insulation of the GCD includes a radiation shield. Each of the radiation shields may be formed of a refractory metal such as tungsten or molybdenum or an alloy thereof. In an embodiment, the at least one radiation shield is formed from tungsten. In another embodiment, the innermost radiation shield (ie, the shield closest to the crucible) is formed of tungsten, and the outermost radiation shield (ie, the shield furthest from the crucible) is Molybdenum composition. The radiation shields can be stacked together and spaced apart by a spacer formed of the same material as the shields. In the embodiment of the invention shown in Figure 1, the GCD is movable relative to the seed cooling assembly 120, the heating element 125, the insulating member 13 and the crucible 150 within the crucible position. The GCD and the 坩埚15〇 can also be moved independently of each other. The mobility of the GCD allows it to control the degree of heat transfer from the vicinity of the bottom of the crucible to alter the temperature gradient of the crucible contents (e.g., growing crystals and melt) as needed. In the implementation of the figure shown, the GCD can be moved along the axis of the seed cooling assembly. In the embodiment shown in Figure i, the thermal shield of the GCD includes an opening to allow the gcd to move along the axis of the seed cooling assembly. The higher the GCD is on the axis, the closer it is to the heating element. In the - high position, such as the map! As shown, the GCD isolates the bottom of the crucible from the seed crystal. As the GCD moves further from the heating element 125, heat near the bottom of the crucible can be dissipated and the temperature gradient of the hanging code increases. The temperature reached by the GCD 159567.doc 201224230 The increase in the gradient is illustrated in Figure 7. The figure shows two temperature gradient curves along the height of the helium in the system of the present invention. The curve on the right shows the temperature gradient along the extinction when gcd is at the high position and the curve on the left shows the temperature gradient when G(3) is at the low position. The temperature gradient along the (four) height at the elevated position is Μ. Placing the GCD in a lower position results in a temperature gradient 'ΛΤ2 along the =. Different temperature gradients are required during different stages of crystal growth. The reduced gradient helps to ensure that all of the charge is melted and the temperature of the melt is as uniform as possible. During the long period of time, the gradient of enthalpy increases ensures that the crystals of the crystals are grown to the top of the melt. During the annealing of the crystal, it is typically more necessary to reduce the gradient of the gradient 1 Lowering the GCD during growth and raising the GCD during melting and annealing results in a higher quality single crystal. Figure 5 illustrates the use of the furnace 1 (e.g., as shown in the figure) to grow around the c-axis according to an embodiment. Method flow for an exemplary method of producing a wafer from a single crystal and thereafter using a seed crystal. In step 505, a seed crystal (eg, sapphire seed crystal) is placed at the bottom of the hazard, for example, The seed receiving area 21 is (as shown in Figure 2). In step 510, a loading material (e.g., a sapphire loading material) is placed in the substrate so that the seed (10) is substantially completely The loading material 14 is covered (as shown in Figure 2). Next, the crucible 150 having the loading (four) and the seed crystal is loaded into the furnace 10. In step 515, energy is supplied to the heating element 125 to heat the Loading material 145 and seed crystal 14 in 坩埚150 Fused above the melting temperature of the loading material 145. For example, for the load on a sapphire material may be a '& amp 159567.doc -11 · 201224230 in the range of from about 2040 to 2100 ° C of;. # "Heated crucible solid target. At this point, the squat can be raised and/or maintained at a high position. The GCD can be raised and/or maintained at a high position to minimize the temperature gradient and ensure a uniform sleek. Once the loading material 145 is completely melted, the molten loading material (also referred to as the "melt" of the loading material) is maintained for a predetermined amount of time to achieve homogenization for typically 1-24 hours. In step 520, the bottom of the stack of defects 150 and the seed just being cooled can be cooled by flowing the cooling fluid 155 through the seed cooling assembly 12 while heating the loading material 145 in step 515. In some embodiments, when the (4) of the loading material is above the melting temperature, helium is used to cool the bottom of the _ 150 and the seed crystal 14 〇. For example, helium gas can be passed through the seed cooling assembly 120 at the bottom of the branch (4) at a rate of between about 100 and about 100 Torr. At least a portion of the seed crystal is allowed to dissolve into the glazing loading material and the bottom of the crucible 150 is cooled to maintain the seed crystal 14 完整 intact and not completely melted. In the case of a seed crystal orientation (the orientation of the axis, the minimum required melting may include melting - a portion of the top surface of the seed crystal (eg, (9)) to form a convex crystal growth surface (as shown in Figure 3). The temperature of the melt and/or the reduction of the flow rate of helium gas through the seed cooling assembly 2〇1 (eg, from lpm to 80 lpm) to melt a small portion of the top surface of the seed crystal 14〇 to form a convex surface ( Or a dome-shaped crystal. The convex crystal growth surface is a true uncustom surface having a plurality of steps composed of different orientations (for example, not the true surface). The convex crystal growth surface contributes to stability substantially Crystal growth process along the £ axis 0 In step 525, crystal growth is initiated (step 525). In the - or more 159567.doc 12 201224230 embodiment 'as the crystal grows, by cooling the component through the seed crystal The flow rate of the cooling fluid 155 is gradually increased to gradually increase the cooling rate of the bottom of the crucible 150. For example, the flow rate of the helium gas can be increased to 600 lpm in a period of 24 to 96. At the same time, it can be substantially slowly reduced. The (equal) heating element The temperature of 125 (e.g., at a rate of about 丨〇2_丨〇 °c / hour) is used to lower the temperature of the solution. Thus, the solution is cooled and forms between the seed and the melt. The temperature gradient can substantially increase the temperature gradient to ensure sustained controlled growth of the crystal and produce a larger solidified single crystal by lowering the GCD 135 during crystal growth and/or keeping the GCD low The position is completed. Lowering the gcd increases the rate of thermal transfer from the vicinity of the seed crystal, thereby increasing the temperature gradient of the crystal and the melt along the growth. For example, the GCD can be reduced by about 1-5 mm/hour. In addition, as the crystal grows taller, the distance from the solid-liquid isotherm from the bottom of the crucible increases and the effect of the cooling fluid 15 decreases, resulting in a steady slowing of the growth rate of the crystal. The reduced growth rate of the crystal can be reduced by moving the seed cooling assembly 120. Lowering the crucible will increase the distance between the crucible and the heating element, thereby allowing the solution to cool and The growth rate of the crystal is maintained. In one embodiment, the stagnation is reduced at a rate of about 0.1 -5 mm/hour. When the crystal growth is completed, the solidified crystal is subjected to an annealing step, wherein the crystal is allowed to cool before the crystal is cooled to room temperature. Maintaining a specific temperature below the melting temperature of the crystal for a specific amount of time. For example, maintaining the heating element at a temperature below the melting point of the crystalline material is about 50-200. (The temperature in the range is sufficient to achieve temperature throughout the crystal. The period of uniformity. This J59567.doc 13 201224230 can reduce the flow of the cooling fluid 155 by reducing the temperature of the heating element 125 to slow the removal of heat from the bottom of the crucible, and move the GCD 135 To a favorable position to achieve a temperature gradient is achieved. For example, the temperature of the heating element can be lowered at a rate of about 0.02 to 50 C / hour and the GCD can be raised during the annealing phase to reduce the temperature gradient to achieve a more uniform temperature. In addition, the hazard may be lifted or maintained at the crystal growth position during the annealing phase to ensure that the cured single crystal is annealed prior to cooling. After annealing, the temperature of the furnace 100 is gradually lowered to gradually and uniformly cool the annealed crystals to room temperature. At this time, the GCD and the cockroach can be kept in the retire position or can be lowered. The rate at which the cooling fluid is cooled to the seed cooling assembly can be further reduced, or the annealing rate can be maintained. In addition, the inert gas pressure in the furnace 1 can be increased before the crystal is removed from the furnace. In step 530, after the crystal growth is completed, the crystal is taken out from the crucible. In step 535, the removed crystal is cored to produce a substantially cylindrical ingot. In one embodiment, the cylindrical ingot is produced by coring substantially perpendicular to the top surface of the fetched crystal (as shown in FIG. 4, in step 540, the coring cylindrical crystal is taken The ingot is sliced to produce a wafer. It should be noted that while Figure 5 depicts the steps of the exemplary method, in an alternative embodiment, those skilled in the art will appreciate that certain steps 'adjustable step sequence' may be changed or omitted. Or an additional step may be included. The equivalent: the step may include evacuating the chamber and backfilling the chamber with a gas such as argon or the like. As described above, during various stages of the method, Manipulating the heating I59567.doc •14· 201224230 The temperature of the component 12 5 , the position of the vortex 15 0 , the flow rate of the cooling fluid in the seed cooling assembly, and the position of the GCD 135 to optimize the production of solid single crystal An example of this is illustrated in Figure 8, which summarizes the state of such parameters during various stages in an embodiment of the invention. While the present embodiments have been described with reference to specific exemplary embodiments, it will be apparent that Implementation Various modifications and changes to the embodiments are possible in the broader spirit and scope of the invention. In addition, it is understood that various operations, processes and methods disclosed herein can be carried out in any order. BRIEF DESCRIPTION OF THE DRAWINGS [BRIEF DESCRIPTION OF THE DRAWINGS] Figure 1 is a cross-sectional view of a furnace for growing a single crystal along a x-axis according to an embodiment; Figures 2 to 4 illustrate the formation of a seed crystal according to a consistent application. Method of taking a cylindrical c-axis cylindrical ingot; Figure 5 is a step of using a furnace (such as shown in the figure) to grow a single crystal around the c-axis and then using the seed crystal to produce a wafer, according to an embodiment. Method flow diagram of an exemplary method; FIG. 6 illustrates an intermediate material between a seed crystal cooling axis and a crucible of a crystal growth system according to the present invention; FIG. 7 is a graphical representation of two different temperature gradients; 8 is a table summarizing the states of various parameters during the various operational stages of the present invention. [Main component symbol description] 159567.doc 15- 201224230 100 Furnace 105 Shell 110 Shell portion 115 Floor 120 Crystal Cooling assembly 125 Heating element 130 Insulation element 135 Gradient control device 140 Seed crystal 145 Loading material 150 Hazard 155 Cooling fluid 210 Seed receiving area 310 Convex crystal growth surface 320 Melt surface 1105 Disc 159567.doc •16-