201107906 六、發明說明： 【發明所屬之技術領域】 本發明有關列印機及特別是MEMS噴墨列印頭之領域 。其主要已被開發至改良MEMS噴墨列印頭之生產，雖然 本發明係同樣地可適用於任何MEMS生產製程。 【先前技術】 ©多不同型式之列印已被發明，大量之列印型式目前 ^系在使用中。列印之習知形式具有用於以有關標記媒體標 記該列印媒體之各種方法。一般使用之列印形式包括按需 噴墨及連續流型式兩者之平板印刷、雷射列印及拷貝裝置 '點矩陣型撞擊式列印機、熱感紙列印機、錄影器、熱蠟 歹IJ印機 '熱昇華列印機、及噴墨列印機。當考慮成本、速 度 '品質、可靠性、結構之單純性及操作等時，列印機之 每一型式具有它們自身之優點及問題。 年來’主要由於其不貴及多用途之本質，噴墨式列 印之領域已變得日漸受歡迎，其中墨水之每一個別像素係 源自一或多個墨水噴嘴。 & 11賁墨式列印上之很多不同技術已被發明。用於該領 域的一項調查，參考一】莫爾“非撞擊式列印：導論及歷 史透視、輸出硬拷貝裝置、編輯R杜布切克（Dubeck ) 及S雪兒^ 曰·冗kSherr)、第207·22〇頁（〗988年）之文章。 D貝墨式列印機本身有很多不同之型式。噴墨式列印中 之墨水的連續液流之利用率顯現爲至少可追溯至1 929年 -5- 201107906 ，其中漢素（Hansell )之美國專利第1 94 1 00 1號揭示連續 液流靜電噴墨式列印的一簡單形式。201107906 VI. Description of the Invention: TECHNICAL FIELD OF THE INVENTION The present invention relates to the field of printers and, in particular, MEMS inkjet printheads. It has primarily been developed to improve the production of MEMS inkjet printheads, although the invention is equally applicable to any MEMS production process. [Prior Art] The printing of many different types has been invented, and a large number of printing patterns are currently in use. The conventional form of printing has various methods for marking the print medium with the associated mark medium. Commonly used printing formats include lithographic printing, laser printing and copying devices for both on-demand inkjet and continuous flow types. 'Dot Matrix Impact Printers, Thermal Paper Printers, Video Recorders, Hot Waxes歹IJ printing machine 'sublimation printing machine, and inkjet printing machine. When considering cost, speed 'quality, reliability, structural simplicity and operation, etc., each type of printer has its own advantages and problems. In the past year, the field of inkjet printing has become increasingly popular due to its inexpensive and versatile nature, where each individual pixel of ink is derived from one or more ink nozzles. & 11 Many different technologies on inkjet printing have been invented. For a survey in this field, reference is made to Moore's “non-impact printing: introduction and historical perspective, output hard copy device, editor R Dubeck and S Chero 曰· redundant kSherr), Article 207.22 (〗 〖988) The D-Bei ink printer itself has many different types. The utilization of the continuous flow of ink in inkjet printing appears to be at least traceable to 1 A simple form of continuous flow electrostatic inkjet printing is disclosed in U.S. Patent No. 1,94,001, issued to Hansell.
Sweet之美國專利第3 5 962 75號揭示亦揭示一連續噴 墨式列印之製程，包括該步驟，其中該噴墨式液流被一高 頻靜電場所調制，以便造成墨滴分離。此技術仍然被包括 Elm jet及Scitex之數個製造廠所利用（亦看Sweet等人之 美國專利第3 3 7343 7號）。 壓電噴墨式列印機亦爲一般利用之噴墨式列印裝置的 一形式。壓電系統被凱斯爾（Kyser)等人揭示於美國專 利第3946398號（197〇年）中，其利用一操作之隔膜模式 ;Zolten於美國專利第3683212號（ 1970年）中，其揭示 一壓電晶體之操作的擠壓模式；Stemme於美國專利第 3747120號（1972年）中揭示壓電操作的一彎曲模式； Howkins於美國專利第4459601號揭示該噴墨式液流的一 壓電推動模式作動；及Fischbeck於美國專利第45 84590 號中揭示壓電傳感器元件的一剪力模式型式。 近來，熱噴墨式列印已變得噴墨式列印的一非常受歡 迎之形式。該噴墨式列印技術包括那些由Endo等人於德 國專利第GB2007162號（ 1979年）中及Vaught等人於美 國專利第4490728號中所揭示者。該前述參考案兩者揭示 噴墨式列印技術，其視一電熱致動器之作動而定，並導致 諸如噴嘴之受限制的空間中之氣泡的建立，其藉此造成墨 水由一連接至該受限制的空間之孔口射出至一有關的列印 媒體上。利用該電熱致動器之列印裝置係藉由諸如佳能及 -6- 201107906 惠普之製造商所製成。 如能由該前文看見，列印技術之很多不同型式係可用 的。理想上，一列印技術將具有許多想要之屬性。這些屬 性包括不貴之結構及操作、高速操作、安全及連續長期操 作等。於成本、速度、品質、可靠性' 耗電量、結構操作 之簡單性、耐用性、及消耗品的領域中，每一技術可具有 其自身之優點及缺點。 本申請人已經開發多種由MEMS技術所製成之噴墨列 印頭。典型地，MEMS生產採用複數光阻劑沈積及移除步 驟。用作光刻罩幕的相當薄光阻劑層（c.a 1微米或更少 )之移除通常係輕易的。標準之條件採用氧電漿，其氧化 地移除一製程中之任何光阻劑，在該技藝中已知爲“灰磨 (ashing) ’’ ° 於噴墨噴嘴組件之生產中，本申請人已採用光阻劑當 作犧牲台架，其他材料（例如加熱器材料、頂板結構）可 被沈積在該犧牲台架上。此技術能夠製成相當複雜之噴嘴 組件。然而，其需要黏性 '耐熱光阻劑的相當厚層之沈積 。如將在下面更詳細地被說明，高達3 0微米之光阻劑層 或插塞可被需要。再者，此光阻劑必需被徹底地烤硬及紫 外線（UV )固化，以致其不會在隨後例如金屬或陶瓷材 料之沈積的高溫沈積步驟期間回流至該光阻劑上。 於一典型之MEMS列印頭生產製程中，一最後之灰磨 步驟移除該噴嘴組件中之所有剩餘的光阻劑，包括於該生 產製程期間所採用之光阻劑台架及光阻劑插塞。至此，傳 201107906 統〇2電漿灰磨技術已被採用於光阻劑之最後或 的移除。 然而’已被烤硬及UV固化的光阻劑之厚層 有增加之阻抗，且藉由傳統之02灰磨技術相當 除。這意指需要拉長之灰磨時間及/或較高的灰 拉長之灰磨時間及/或較高的灰磨溫度係不想要 在該灰磨製程期間有對其他MEM S結構（例如噴 動器）造成增加損壞之風險。再者，大致上，有 MEMS處理步驟之效率的需要，以便減少處理時 減少每一列印頭之成本。 〇2與氟化氣體（例如CF4 )之結合係已知可 比率。然而，該申請人已發現該〇2/cf4氣體化 要大量CF4 ( >10% )，以提供改善之灰磨比率。 高濃度處，該等灰磨條件在該申請人的列印頭中 噴嘴結構上具有一有害的影響。因此，用於由該 列印頭移除烤硬的光阻劑，〇2/CF4已證實爲不能 的。 用於烤硬的光阻劑之移除，〇2/N2之使用係 改善灰磨比率，雖然N2之加入僅只顯示優於純 改善。 據此，由該前文，應了解有一改善MEMS生 之光阻劑移除的效率之需要。 其將爲進一步想要的是伴隨以光阻劑移除由 通孔移除‘面罩（veil ) ’ 。蝕刻後殘留物或‘ 晚期階段 對灰磨具 緩慢地移 磨溫度。 的，因爲 嘴室、致 增加每一 間及最終 改善灰磨 學成份需 在CF4之 之氮化矽 申請人之 令人滿意 亦已知可 32之適當 產技術中 被蝕刻之 面罩’沿 -8- 201107906 著通孔側壁形成’如各向異性蝕刻製程（例如博希法）之 副產物。面罩係該技藝中早已認知之問題，且係以難以移 除出名。面罩典型包含被蝕刻材料之截留種類，其大致上 係砂-氧-碳化合物。聚合物形成之各向異性蝕刻化學（例 如博希法）建立面罩通常僅只可使用侵蝕性的、濕式化學 溶劑被移除。再者，在升高的溫度使用〇2之傳統灰磨典 型使面罩之問題惡化’使得它們甚至更難以被移除。據此 ’有一乾纟呆式揭開製程之需要’該製程係可靠的，且不需 要可損壞該晶圓之侵蝕性的濕式化學藥品》 雖然該上述之需要已被呈現在列印頭生產之情況中， 應了解任何M EM S生產製程將自用於光阻劑移除及/或揭 開的改良技術獲益，特別是那些使用一已被烤硬及/或υν 固化的犧牲光阻劑之厚層的MEMS生產製程。 【發明內容】 於第一態樣中，提供有一由基板移除光阻劑之方法， 該方法採用由一氣體化學成份所形成之電發，該氣體化學 成份包括：〇2、ΝΗ3及含氟氣體。與使用傳統02電漿或 〇2/Ν2電獎之灰磨比率比較，根據本發明之方法令人驚言牙 及有利地改善灰磨比率達至少2 0 % '至少5 0 %或至少 100% ° 與傳統〇2或〇2/Ν2灰磨電獎對照，根據本發明之方 法伴隨地揭開該基板中之被鈾刻的孔。 選擇性地，含氟氣體係cF4。 * 9 - 201107906 選擇性地，.該含氟氣體係以少於5體積百分比之濃度 存在於該氣體化學成份中。 含氟氣體之數量通常被保持低的，以便避免損壞該基 板中之任何氮化矽列印頭結構。 選擇性地，該含氟氣體係以少於3體積百分比之濃度 存在於該氣體化學成份中。 選擇性地，〇2:NH3之比率係於20:1至5:1之範圍中 〇 選擇性地，02:CF4之比率係於40:1至20:1之範圍中 〇 選擇性地，該氣體化學成份僅只由〇2、NH3及CF4所 組成。 然而，如果需要，諸如氦及氬之惰性氣體可爲存在於 該氣體化學成份中。 選擇性地’該光阻劑係烤硬的光阻劑及/或紫外線固 化之光阻劑，其係特別難以使用傳統之〇2或o2/n2灰磨 電漿移除。再者，傳統灰磨電漿之使用通常留下於本身中 有問題之殘留物‘面罩（veil ) ’ 。 選擇性地’該光阻劑具有至少5微米之厚度，諸如於 該形成MEMS結構（例如噴墨噴嘴組件）中用作犧牲台架 之光阻劑。 選擇性地’該基板係附接至一夾頭，且該夾頭被冷卻 至一在攝氏-5至-30度的範圍中之溫度。 選擇性地’該方法係微機電系統（MEMS )生產製程 -10 - 201107906 、諸如列印頭生產製程的一步驟。 選擇性地，該光阻劑被包含於噴墨噴嘴室及/或墨水 供給通道中。 選擇性地，該光阻劑係一用於噴墨噴嘴組件之保護塗 料、及/或一用於各向異性深反應離子蝕刻（DRIE )製程 之罩幕。 於第二態樣中，提供有一製造噴墨列印頭之方法，該 方法包括以下步驟： 形成一晶圓基板的前側上之噴墨噴嘴室，每一噴嘴室 具有一以光阻劑塡塞之對應的墨水入口； 由該晶圓基板之背面蝕刻墨水供給通道，以與該等用 光阻劑塡塞之墨水入口相合；及 移除至少部份該光阻劑，且藉由使該背面經受由第一 氣體化學成份所形成之第一電漿伴隨地揭開該等墨水供給 通道，該第一氣體化學成份包括：02、NH3及含氟氣體。 選擇性地，該方法包括另一步驟： 藉由使該前側經受由第二氣體化學成份所形成之第二 電漿而進一步移除光阻劑，該第二氣體化學成份包括：02 及 nh3。 【實施方式】 如上面所預示，本發明可與任何需要移除光阻劑之 程有關地被使用。然而，其現在將使用MEMS噴墨列印頭 生產之範例例示。本申請人先前已敘述本發明所合適之多 -11 - 201107906 種噴墨列印頭的生產。其在此用於本發明之理解係不需要 敘述所有此等列印頭。然而，本發明現在將敘述有關一熱 氣泡形成噴墨列印頭及一機械熱彎曲作動式噴墨列印頭。 本發明之優點將由隨後之討論輕易地變得明顯。 參考圖1，顯示有一部份列印頭，該列印頭包括複數 噴嘴組件。圖2及3於側剖視圖及切開透視圖中顯示這些 噴嘴組件之一。 每一噴嘴組件包括一在矽晶圓基板2上藉由MEMS生 產技術所形成之噴嘴室24。該噴嘴室24係藉由一頂板2 1 及側壁22所界定’該等側壁由該頂板2丨延伸至該矽基板 2。如圖1所示’每一頂板係藉由一部份噴嘴板5 6所界定 ，該部份噴嘴板橫跨該列印頭的一射出面。該噴嘴板56 及側壁2 2係由相同材料所形成，該材料係於μ E M S生產 期間藉由PECVD沈積在光阻劑之犧牲台架上方。該噴嘴 板5 6及側壁2 1典型係由諸如二氧化矽或氮化矽之陶瓷材 料所形成。這些堅硬的材料具有用於列印頭堅固性之優異 性質’且其固有之親水本質係有利的，用於藉由毛細管作 用將墨水供給至該等噴嘴室24。 返回至該噴嘴室24之細節，其將被看出一噴嘴開口 26被界定於每一噴嘴室24之頂板中。每一噴嘴開口 26大 致上係橢圓的，且具有—相關之噴嘴邊緣2 5。該噴嘴邊緣 2 5於列印期間輔助墨滴方向性以及至少在某種程度減少墨 水由該噴嘴開口 26溢流。用於由該噴嘴室24排出墨水之 致動器係一加熱器元件29，其被定位在該噴嘴開口 26下 -12- 201107906 方及懸置越過一凹處8。電流係在該基板2之下列C Μ 0 S 層中經由連接至驅動電路系統之通孔電極9供給至該加熱 器元件29。當一電流係通過該加熱器元件29時，其迅速 地過熱周圍之墨水’以形成一強迫墨水經過該噴嘴開口之 氣體氣泡。藉由懸置該加熱器元件29，其當該噴嘴室24 被裝塡時被完全地浸入墨水中。這改善列印頭效率，因爲 更少之熱消散進入在下方之基板2，且更多輸入能量被使 用於產生一氣泡。 如在圖1中最清楚地看見，該等噴嘴被成排地配置， 且一沿著該列縱向地延伸之墨水供給通道2 7將墨水供給 至該列中之每一噴嘴。該墨水供給通道2 7運送墨水至用 於每一噴嘴的一墨水入口通道〗5，其自該噴嘴開口 26之 側面經由該噴嘴室24中之墨水導管2 3供給墨水。 用於製造此等列印頭之完整MEMS生產製程被詳細地 敘述於我們先前地提出之美國申請案專利第1 1 /246,6 84號 中’其係在200 5年10月1 1日提出，其內容係以引用的 方式倂Λ本文中。此生產製程之稍後階段係在此簡短地再 參觀’以便說明本發明的一範例。 圖4及5顯示一局部製成之列印頭，包括一封裝犧牲 光阻劑1 6之噴嘴室24。於噴嘴生產期間，該光阻劑1 6首 先被使用，以_塞該墨水入口 i 5 (圖2所示），其次當作 一用於加熱器材料之沈積的台架，以形成該懸置之加熱器 元件29 ’且第三當作—用於該等側壁22及頂板2 1之沈積 的台架（其界定該噴嘴板5 6的一部份）。塡塞該墨水入 -13- 201107906 口 15之光阻劑具有大約2〇微米之深度，而用作該等噴嘴 室中之台架的光阻劑具有至少5微米之厚度。再者，所有 該光阻劑1 ό被烤硬及UV固化，且在該生產製程中必須 被稍後移除。 參考圖6至8，MEMS生產之下一階段藉由蝕刻離開 2微米之頂板材料20界定該頂板21中之橢圓的噴嘴邊緣 25。該餓刻係使用一層光阻劑（未示出）所界定，該層光 阻劑藉由圖6所示之暗色調邊緣罩幕所曝光。該橢圓的邊 緣25包括定位在其個別之熱致動器29上方的二同軸向之 邊緣唇部25a及25b。 參考圖9至1 1，該下一階段藉由一直蝕刻穿過該剩餘 之頂板材料2〇界定該頂板21中之一橢圓的噴嘴孔口 26， 該噴嘴孔口係藉由該邊緣2 5所限制。該蝕刻係使用一層 光阻劑（未示出）所界定，該層光阻劑藉由圖9所示之暗 色調頂板罩幕所曝光。該橢圓的噴嘴孔口 2 6被定位在該 熱致動器29上方，如圖11所示》 —旦該晶圓之前側MEMS處理被完成，該晶圓係接著 藉由背面硏磨及蝕刻變薄至大約1 50微米之厚度（圖1 2 與1 3 )。在晶圓變薄之後，由該晶圓之背面蝕刻墨水供給 通道27，以使用一標準之各向異性DRIE與該等墨水入口 1 5相合（圖1 4至1 6 )。此背面蝕刻係使用一層藉由圖1 4 所示之暗色調罩幕所曝光的烤硬光阻劑50所界定。在移 除所有用於前側MEMS噴嘴組件之生產的犧牲光阻劑1 6 之後，該墨水供給通道27將在該晶圓的背面及該等墨水 -14- 201107906 入口 1 5之間造成一流體的連接。 該光阻劑之移除首先以背面灰磨進行，以移除該背面 烤硬的光阻劑層5 0及插塞該前側墨水入口 1 5的光阻劑i 6 之插塞的一部份（圖1 7與1 8 )。背面灰磨利用在下面範 例中所敘述之灰磨條件，該範例具有連續之三階段灰磨製 程。 於一傳統之灰磨製程中，02電漿被採用於灰磨該光阻 劑1 6。然而’按照本發明，該灰磨電漿係使用一包括〇2 、NH3及CF4之氣體化學成份所形成。當該電漿係由一包 括此氣體化學成份之氣體化學成份所形成時，以增加灰磨 比率及減少對噴嘴結構的損壞之觀點達成優越灰磨。再者 ’源自該等墨水供給通道2 7之背面各向異性触刻的面罩 係亦使用此氣體化學成份被移除，而不須面罩之侵蝕性濕 式化學移除。灰磨條件之實驗細節係更詳細地敘述在下面 之範例段落中。 最後，前側灰磨移除該光阻劑1 6之剩餘部份，以提 供圖1至3所示之完成的列印頭。前側灰磨可利用按照本 發明之〇2/NH3/CF4氣體化學成份。另—選擇係，前側灰 磨可利用一 〇2/nh3氣體化學成份，如該申請人之美國專 利公告第US 2009/007 8 67 5號所敘述，其內容係以引用的 方式倂入本文中。 圖1於一完成之列印頭積體電路的切開透視圖中顯示 三鄰接列之噴嘴。每一列噴嘴具有沿著其長度延伸及供給 墨水至每一列中之複數墨水入口 1 5的個別之墨水供給通 -15- 201107906 道2 7。該等墨水入口依序供給墨水至用於每一列之墨水導 管23，使每一噴嘴室承接來自用於該列之共用墨水導管的 墨水 熟諳此技藝者應了解該晚期階段MEMS生產步驟之正 確順序可被變化。譬如，該晶圓可爲僅只經受背面灰磨或 僅只經受前側灰磨。無論如何，應了解該晶圓必需經受前 側灰磨及/或背面灰磨的其中之一，以便移除該光阻劑1 6 及供給該列印頭。 範例 圖1 7及1 8所示晶圓之背面灰磨係於一灰磨烘箱中施 行，使用表1所示之最佳化的灰磨順序。工作程序1被使 用達1 5分鐘，隨後使用工作程序2達5分鐘，且後接著 使用工作程序3達1 〇分鐘。表1中之溫度意指該夾頭溫 度，其係使用氨冷卻。 工作程序1 工作程序2 工作程序3 壓力（毫陶爾） 80 20 20 ICP功率（瓦） 2200 2200 2200 NH3 ( seem ) 10 10 10 〇2 ( seem ) 100 100 100 CF4 ( seem ) 3 3 0 溫度（攝氏） -20 -20 -20 時間（分） 15 5 10 表1 在表1所示的連續灰磨條件之下，觀察到一優異之光 -16- 201107906 阻劑移除比率。再者’該墨水供給通道2 7及該墨水入口 已被完全地揭開，如藉由S EM所確認。經由比較，傳統 之〇2灰磨或〇2川2灰磨需要大約70-90分之灰磨時間，以 移除相同之光阻劑，且留下相當多之必需被隨後的濕式化 學處理所移除之面罩。 如所期待的’在使用該o2/n2/cf4氣體化學成份之前 側灰磨實驗中亦觀察到優異之灰磨比率及揭開。 與傳統之灰磨條件作比較，由這些實驗，其能下結論 包括〇2/N2/CF4之氣體化學成份在揭開中提供優越之灰磨 比率及令人驚訝之功效。 於此領域中之普通工作者應了解可對本發明作成極多 變化及/或修改’如該等特定具體實施例中所示，而不會 由本發明之寬廣地敘述的精神或範圍脫離。因此，本具體 實施例將在所有方面被考慮爲說明性及非限制性的。 【圖式簡單說明】 現在將參考所附圖面僅只當作範例地敘述本發明之面 選擇性具體實施例，其中： 圖1係一熱噴墨列印頭之噴嘴組件陣列的局部透視圖 1 圖2係圖1所示噴嘴組件單格之側視圖； 圖3係圖2所示噴嘴組件之透視圖； 圖4顯示一在側壁及頂板材料沈積於犧牲光阻劑層上 之後的局部形成噴嘴組件； -17- 201107906 圖5係圖4所示噴嘴組件之透視圖； 圖6係與圖7所示噴嘴邊緣蝕刻有關之罩幕； 圖7顯示該頂板層之蝕刻，以形成該噴嘴開口邊緣； 圖8係圖7所示噴嘴組件之透視圖； 圖9係與圖1 0所示噴嘴開口蝕刻有關之罩幕； 圖1 〇顯示該頂板材料之蝕刻，以形成該橢圓的噴嘴 開口； 圖1 1係圖1 〇所示噴嘴組件之透視圖； 圖1 2顯示在背面晶圓變薄之後的噴嘴組件； 圖1 3係圖1 2所示噴嘴組件之透視圖； 圖1 4係與圖1 5所示背面蝕刻有關之罩幕； 圖1 5顯示進入該晶圓之墨水供給通道的背面蝕刻； 圖1 6係圖1 5所不噴嘴組件之透視圖， 圖1 7顯示在背面灰磨之後的噴嘴組件；及 圖1 8係圖1 7所示噴嘴組件之透視圖。 【主要元件符號說明】 2 :基板 8 :凹處 9 :電極 1 5 :墨水入口通道 1 6 :光阻劑 20 :頂板材料 2 1 :頂板 -18- 201107906 22 :側壁 2 3 :墨水導管 2 4 :噴嘴室 2 5 :噴嘴邊緣 2 5 a :邊緣唇部 2 5b :邊緣唇部 2 6 :噴嘴開口 2 7 :墨水供給通道 2 9 :加熱器元件 5 0 :光阻劑層 5 6 :噴嘴板A process of continuous ink jet printing is also disclosed in U.S. Pat. This technology is still used by several manufacturing plants including Elm Jet and Scitex (see also US Patent No. 3 3 7343 7 to Sweet et al.). Piezoelectric ink jet printers are also a form of ink jet printing apparatus that is generally used. A piezoelectric system is disclosed by Kyser et al. in U.S. Patent No. 3,946,398 (197), which utilizes an operational diaphragm mode; Zolten, U.S. Patent No. 3,683,212 (1970), which discloses A squeezing mode of the operation of a piezoelectric crystal; a bending mode of piezoelectric operation is disclosed in US Pat. No. 3,747,120 (1972); A mode of operation of a piezoelectric sensor element is disclosed in U.S. Patent No. 4,545,590 to Fischbeck. Recently, thermal ink jet printing has become a very popular form of ink jet printing. The ink jet printing technique includes those disclosed by Endo et al. in German Patent No. GB2007162 (1979) and by Vaught et al. in U.S. Patent No. 4,490,728. Both of the aforementioned references disclose an ink jet printing technique that depends on the actuation of an electrothermal actuator and results in the creation of bubbles in a restricted space, such as a nozzle, which thereby causes the ink to be connected by The aperture of the restricted space is ejected onto an associated printing medium. The printing device using the electrothermal actuator is made by a manufacturer such as Canon and -6-201107906 Hewlett-Packard. As can be seen from the foregoing, many different types of printing techniques are available. Ideally, a print technology will have many desirable attributes. These attributes include inexpensive construction and operation, high speed operation, safety and continuous long-term operation. Each technology can have its own advantages and disadvantages in the areas of cost, speed, quality, reliability, power consumption, simplicity of structural operation, durability, and consumables. The Applicant has developed a variety of ink jet printheads made by MEMS technology. Typically, MEMS production employs a complex photoresist deposition and removal step. Removal of a relatively thin photoresist layer (c.a 1 micron or less) used as a lithography mask is generally easy. Standard conditions employ an oxygen plasma that oxidatively removes any photoresist in a process, known in the art as "ashing" in the production of inkjet nozzle assemblies, the applicant A photoresist has been used as a sacrificial gantry, and other materials (such as heater material, top plate structure) can be deposited on the sacrificial gantry. This technique can be used to make quite complex nozzle assemblies. However, it requires viscosity. The deposition of a relatively thick layer of a heat resistant photoresist. As will be explained in more detail below, a photoresist layer or plug of up to 30 microns may be required. Again, the photoresist must be thoroughly baked. And ultraviolet (UV) curing so that it does not reflow onto the photoresist during subsequent high temperature deposition steps such as deposition of metal or ceramic materials. In a typical MEMS printhead manufacturing process, a final gray mill The step removes all remaining photoresist in the nozzle assembly, including the photoresist gantry and photoresist plug used during the production process. At this point, the 201107906 rectification 2 plasma ash grinding technology has been Used in photoresist Final removal. However, the thick layer of the photoresist that has been baked hard and UV-cured has an increased impedance and is quite divided by the conventional 02-grinding technique. This means that the grinding time is required to be elongated and / or higher gray-grown ashing time and / or higher ashing temperature is not expected to cause increased damage to other MEM S structures (such as sprayers) during the ashing process. In general, there is a need for the efficiency of the MEMS processing steps in order to reduce the cost of each print head during processing. The combination of 〇2 with a fluorinated gas (such as CF4) is known to be a ratio. However, the applicant has found The 〇2/cf4 gasification requires a large amount of CF4 (>10%) to provide an improved ash ratio. At high concentrations, the ash conditions have a deleterious effect on the nozzle structure in the applicant's print head. Therefore, for the removal of the baked photoresist from the print head, 〇2/CF4 has proven to be unacceptable. For the removal of baked hard photoresist, the use of 〇2/N2 is improved. Gray grinding ratio, although the addition of N2 only shows better than pure improvement. According to this, by the above It should be understood that there is a need to improve the efficiency of photoreceptor removal by MEMS. It would be further desirable to remove the 'veil' from the via with the removal of the photoresist. After etching or 'In the late stage, the ash is slowly moved to the temperature. Because the mouth chamber, the increase in each and the final improvement of the ash-grinding composition, the need for nitriding in CF4 is satisfactory. The etched mask in the appropriate production technique 'forms the sidewall of the via along -8-201107906' as a by-product of an anisotropic etching process (such as Bosch), which is a problem that has long been recognized in the art and is It is difficult to remove the name. The mask typically contains a cut-off type of material to be etched, which is roughly a sand-oxygen-carbon compound. The anisotropic etch chemistry of polymer formation (e.g., Bosch) creates masks that are typically only removed using aggressive, wet chemical solvents. Moreover, the use of conventional ashing patterns of 〇2 at elevated temperatures exacerbates the problem of masks' making them even more difficult to remove. According to this, there is a need for a dry process to uncover the process. The process is reliable and does not require aggressive wet chemicals that can damage the wafer. Although the above needs have been presented in the production of print heads. In this case, it should be understood that any M EM S manufacturing process will benefit from improved techniques for photoresist removal and/or uncovering, particularly those using a sacrificial photoresist that has been cured by baking and/or υν. Thick layer of MEMS production process. SUMMARY OF THE INVENTION In a first aspect, a method for removing a photoresist from a substrate is provided. The method uses an electric wave formed by a gas chemical composition including: 〇2, ΝΗ3, and fluorine. gas. Compared to the ashing ratio using conventional 02 plasma or 〇2/Ν2 electric prize, the method according to the invention surprisingly improves the ashing ratio by at least 20% 'at least 50% or at least 100% ° In contrast to conventional 〇2 or 〇2/Ν2 ash-grinding awards, the uranium-engraved holes in the substrate are concomitantly removed in accordance with the method of the present invention. Optionally, the fluorine-containing gas system cF4. * 9 - 201107906 Optionally, the fluorine-containing gas system is present in the gas chemistry at a concentration of less than 5 volume percent. The amount of fluorine-containing gas is typically kept low to avoid damaging any tantalum nitride printhead structure in the substrate. Optionally, the fluorine-containing gas system is present in the gas chemistry at a concentration of less than 3 volume percent. Optionally, the ratio of 〇2:NH3 is in the range of 20:1 to 5:1 〇 selectively, and the ratio of 02:CF4 is in the range of 40:1 to 20:1 〇 selectively, The gas chemical composition consists only of 〇2, NH3 and CF4. However, if desired, an inert gas such as helium and argon may be present in the gas chemistry. Optionally, the photoresist is a bake hard photoresist and/or an ultraviolet curable photoresist which is particularly difficult to remove using conventional 〇2 or o2/n2 ash plasma. Moreover, the use of conventional ash-grinding plasma typically leaves the problematic 'veil' in its own problem. Optionally, the photoresist has a thickness of at least 5 microns, such as a photoresist used as a sacrificial gantry in the formation of a MEMS structure, such as an inkjet nozzle assembly. Optionally, the substrate is attached to a collet and the collet is cooled to a temperature in the range of -5 to -30 degrees Celsius. Optionally, the method is a microelectromechanical system (MEMS) manufacturing process -10 - 201107906, a step such as a printhead manufacturing process. Optionally, the photoresist is included in the ink jet nozzle chamber and/or the ink supply channel. Optionally, the photoresist is a protective coating for an ink jet nozzle assembly, and/or a mask for an anisotropic deep reactive ion etching (DRIE) process. In a second aspect, there is provided a method of fabricating an ink jet print head, the method comprising the steps of: forming an ink jet nozzle chamber on a front side of a wafer substrate, each nozzle chamber having a photoresist plug Corresponding ink inlet; etching an ink supply passage from a back surface of the wafer substrate to engage the ink inlets of the photoresist plugging; and removing at least a portion of the photoresist, and by using the back surface The first plasma formed by the first gas chemistry simultaneously uncovers the ink supply channels, the first gas chemistry comprising: 02, NH3, and a fluorine-containing gas. Optionally, the method includes the further step of: further removing the photoresist by subjecting the front side to a second plasma formed from a second gas chemistry comprising: 02 and nh3. [Embodiment] As indicated above, the present invention can be used in connection with any process requiring removal of a photoresist. However, it will now use the exemplary illustration of MEMS inkjet printhead production. The Applicant has previously described the production of a plurality of ink jet print heads suitable for the present invention. It is not necessary to describe all such print heads as used herein for the understanding of the present invention. However, the present invention will now be described with respect to a thermal bubble forming ink jet print head and a mechanical thermal bending actuated ink jet print head. The advantages of the present invention will be readily apparent from the discussion that follows. Referring to Figure 1, there is shown a portion of a printhead that includes a plurality of nozzle assemblies. Figures 2 and 3 show one of these nozzle assemblies in a side cross-sectional view and a cutaway perspective view. Each nozzle assembly includes a nozzle chamber 24 formed on the tantalum wafer substrate 2 by MEMS fabrication techniques. The nozzle chamber 24 is defined by a top plate 21 and a side wall 22 from which the side walls extend to the crucible substrate 2. As shown in Fig. 1, each of the top plates is defined by a portion of the nozzle plate 56 which spans an exit face of the print head. The nozzle plate 56 and the side wall 22 are formed of the same material which is deposited by PECVD over the sacrificial stage of the photoresist during the production of the μ E M S. The nozzle plate 56 and the side wall 21 are typically formed of a ceramic material such as cerium oxide or tantalum nitride. These hard materials have excellent properties for the robustness of the print head' and their inherent hydrophilic nature is advantageous for supplying ink to the nozzle chambers 24 by capillary action. Returning to the details of the nozzle chamber 24, it will be seen that a nozzle opening 26 is defined in the top plate of each nozzle chamber 24. Each nozzle opening 26 is generally elliptical and has an associated nozzle edge 25. The nozzle edge 25 assists ink droplet directivity during printing and at least somewhat reduces ink overflow from the nozzle opening 26. The actuator for discharging ink from the nozzle chamber 24 is a heater element 29 that is positioned below the nozzle opening 26 -12-201107906 and overhangs a recess 8. Current is supplied to the heater element 29 via the via electrodes 9 connected to the drive circuitry in the following C Μ 0 S layers of the substrate 2. As a current passes through the heater element 29, it rapidly overheats the surrounding ink to form a gas bubble that forces ink through the nozzle opening. By suspending the heater element 29, it is completely immersed in the ink when the nozzle chamber 24 is mounted. This improves the efficiency of the printhead because less heat dissipates into the substrate 2 below and more input energy is used to create a bubble. As best seen in Figure 1, the nozzles are arranged in rows, and an ink supply channel 27 extending longitudinally along the column supplies ink to each of the nozzles. The ink supply passage 27 carries ink to an ink inlet passage 5 for each nozzle, which supplies ink from the side of the nozzle opening 26 via the ink conduit 23 in the nozzle chamber 24. The complete MEMS production process for the manufacture of such printheads is described in detail in our previously filed U.S. Patent Application Serial No. 1 1 /246, No. 6,84, the entire disclosure of which was filed on October 1, 2005. The content of this article is cited in this article. A later stage of this production process is briefly revisited here to illustrate an example of the present invention. Figures 4 and 5 show a partially fabricated printhead including a nozzle chamber 24 encapsulating a sacrificial photoresist 16. During nozzle production, the photoresist 16 is first used to plug the ink inlet i 5 (shown in Figure 2), and secondly as a gantry for deposition of heater material to form the suspension. The heater element 29' and the third are considered as a gantry for the deposition of the side walls 22 and the top plate 21 (which defines a portion of the nozzle plate 56). The photoresist is occluded into -13-201107906. The photoresist of the mouth 15 has a depth of about 2 〇 microns, and the photoresist used as the gantry in the nozzle chambers has a thickness of at least 5 μm. Furthermore, all of the photoresist 1 is baked and cured by UV and must be removed later in the manufacturing process. Referring to Figures 6 through 8, the next stage of MEMS production defines an elliptical nozzle edge 25 in the top plate 21 by etching away from the 2 micron top plate material 20. The starvation is defined by a layer of photoresist (not shown) exposed by a dark-tone edge mask as shown in FIG. The edge 25 of the ellipse includes two axial edge lips 25a and 25b positioned above their respective thermal actuators 29. Referring to Figures 9 through 1, the next stage defines an elliptical nozzle orifice 26 in the top plate 21 by etching through the remaining top plate material 2, the nozzle orifice being by the edge 25 limit. The etch is defined by a layer of photoresist (not shown) exposed by a dark-tone top mask as shown in FIG. The elliptical nozzle aperture 26 is positioned above the thermal actuator 29, as shown in FIG. 11 - once the wafer front side MEMS processing is completed, the wafer is then etched and etched by backside etch Thin to a thickness of approximately 1 50 microns (Figures 1 2 and 13). After the wafer is thinned, the ink supply channel 27 is etched from the back side of the wafer to coincide with the ink inlets 15 using a standard anisotropic DRIE (Figs. 14 to 16). This backside etching is defined by a layer of baked hard photoresist 50 exposed by the dark shade mask shown in FIG. After removing all of the sacrificial photoresist 16 for the production of the front side MEMS nozzle assembly, the ink supply channel 27 will create a fluid between the back side of the wafer and the ink 14-201107906 inlet 15 connection. The removal of the photoresist is first performed by backside ashing to remove the backside baked photoresist layer 50 and a portion of the plug of the photoresist i6 plugging the front side ink inlet 15 (Figures 1 7 and 1 8). Backside ashing utilizes the ashing conditions described in the following examples, which have a continuous three-stage ashing process. In a conventional ash grinding process, 02 plasma is used to ash the photoresist 16. However, in accordance with the present invention, the ash-grinding plasma is formed using a gas chemistry comprising ruthenium 2, NH3, and CF4. When the plasma is formed from a gas chemistry comprising the gas chemistry, superior ash grinding is achieved from the standpoint of increasing the ash ratio and reducing damage to the nozzle structure. Further, the mask from the back anisotropic etch of the ink supply channels 27 is also removed using this gas chemistry without the aggressive wet chemical removal of the mask. Experimental details of the grey grinding conditions are described in more detail in the following example paragraphs. Finally, the front side ash removes the remainder of the photoresist 16 to provide the finished print head shown in Figures 1-3. The front side ash can utilize the 〇2/NH3/CF4 gas chemistry according to the present invention. Alternatively, the selection system, the front side of the sanding may utilize a 〇2/nh3 gas chemistry, as described in the Applicant's US Patent Publication No. US 2009/007 8 67 5, the contents of which are incorporated herein by reference. . Figure 1 shows a nozzle of three adjacent columns in a cut-away perspective view of a completed printhead integrated circuit. Each row of nozzles has an individual ink supply passage -15-201107906, which extends along its length and supplies ink to a plurality of ink inlets 15 in each column. The ink inlets sequentially supply ink to the ink conduits 23 for each column, such that each nozzle chamber receives ink from a common ink conduit for the column. The skilled artisan should understand the correct sequence of the late stage MEMS production steps. Can be changed. For example, the wafer can be only subjected to backside ashing or only to front side ashing. In any event, it should be understood that the wafer must be subjected to one of front side sanding and/or back side sanding in order to remove the photoresist 16 and supply the print head. EXAMPLES The backside ash of the wafers shown in Figures 1 and 8 was performed in a ash oven using the optimized ash milling sequence shown in Table 1. Work program 1 is used for 15 minutes, then work program 2 is used for 5 minutes, and then work program 3 is used for 1 minute. The temperature in Table 1 means the temperature of the chuck, which is cooled using ammonia. Work Procedure 1 Work Procedure 2 Work Procedure 3 Pressure (Motao) 80 20 20 ICP Power (Watts) 2200 2200 2200 NH3 ( seem ) 10 10 10 〇 2 ( seem ) 100 100 100 CF4 ( seem ) 3 3 0 Temperature ( Celsius) -20 -20 -20 Time (minutes) 15 5 10 Table 1 Under the continuous ash grinding conditions shown in Table 1, an excellent light-16-201107906 resist removal ratio was observed. Further, the ink supply passage 27 and the ink inlet have been completely uncovered, as confirmed by S EM. By comparison, the conventional 〇 2 ash or 〇 2 2 ash grinding requires about 70-90 ash grinding time to remove the same photoresist, leaving a considerable amount of subsequent wet chemical treatment The mask removed. As expected, an excellent ash ratio and uncovering were also observed in the side ash grinding experiment prior to the use of the o2/n2/cf4 gas chemistry. In comparison with conventional ash grinding conditions, from these experiments, it can be concluded that the gas chemical composition of 〇2/N2/CF4 provides superior ash milling ratio and surprising efficacy in uncovering. A person skilled in the art will appreciate that many variations and/or modifications may be made to the present invention as shown in the specific embodiments without departing from the spirit or scope of the invention. Therefore, the present embodiments are to be considered in all respects illustrative and not limiting. BRIEF DESCRIPTION OF THE DRAWINGS A surface selective embodiment of the present invention will now be described by way of example only with reference to the accompanying drawings in which: FIG. 1 is a partial perspective view of an array of nozzle assemblies of a thermal inkjet print head Figure 2 is a side view of the nozzle assembly of Figure 1; Figure 3 is a perspective view of the nozzle assembly of Figure 2; Figure 4 shows a partially formed nozzle after the sidewall and top material are deposited on the sacrificial photoresist layer. Figure 1-5 is a perspective view of the nozzle assembly shown in Figure 4; Figure 6 is a mask associated with the edge etching of the nozzle shown in Figure 7; Figure 7 shows the etching of the top layer to form the edge of the nozzle opening Figure 8 is a perspective view of the nozzle assembly shown in Figure 7; Figure 9 is a mask associated with the nozzle opening etching shown in Figure 10; Figure 1 shows the etching of the top plate material to form the elliptical nozzle opening; 1 1 is a perspective view of the nozzle assembly shown in FIG. 1; FIG. 1 2 shows the nozzle assembly after the back wafer is thinned; FIG. 1 is a perspective view of the nozzle assembly shown in FIG. 12; 15 shows the backside etching related to the mask; Figure 1 5 shows the The back side of the ink supply channel of the wafer is etched; FIG. 16 is a perspective view of the nozzle assembly of FIG. 15, FIG. 7 shows the nozzle assembly after the back grinding; and FIG. A perspective view of the component. [Main component symbol description] 2: Substrate 8: Recess 9: Electrode 1 5: Ink inlet channel 1 6 : Photoresist 20: Top plate material 2 1 : Top plate -18- 201107906 22: Side wall 2 3 : Ink conduit 2 4 : nozzle chamber 2 5 : nozzle edge 2 5 a : edge lip 2 5b : edge lip 2 6 : nozzle opening 2 7 : ink supply channel 2 9 : heater element 5 0 : photoresist layer 5 6 : nozzle plate