201242197 六、發明說明： 【發明所屬之技術領域】 本發明之實施例大致上有關於固態雷射之控制。更特 定言之，本發明之實施例有關於用於在異常事件期間關 閉固態雷射之方法。 【先前技術】 固態雷射在各種領域中有諸多應用。舉例而言，於針 對積體電路裝置、薄膜電晶體裝置、可撓性基板應用、 有機發光二極體與太陽能電池裝置之製造之基板處理期 間可使用固態雷射。固態雷射之一項應用為用在各種裝 置之製造製程期間基板之快速熱退火。 第1圖繪示用於基板處理之基於雷射的退火系統之示 意圖。基於雷射的基板退火系統包含系統控制器1 〇、雷 射電源供應器12、雷射13及硬體保護系統a，雷射13 包含雷射外殼主體及位於該外殼主體内、用以產生雷射 光束14的必要部件。可使用基於雷射的退火系統藉由雷 射光束14來退火基板15或基板15之部份。系統控制器 1〇產生控制訊號17以設定雷射電源供應器12之輸出電 流或功率使具有雷射電流控制訊號9。藉由改變雷射Η 之操作電流或功率，控制器設定雷射光束14之能量，且 因此設定基板15之退火溫度。 若在晶圓處理期間發生系統故障，硬體保護系統16 藉由改變互鎖訊號18之狀態從打開（〇>〇變成關閉（〇ff) 201242197 以關閉雷射電源供應器12。自雷射電源供應器i2移除 =訊號18突然地將雷射電流訊號9(且因此雷射功率） 叹=為零。由於雷射溫度取決於雷射電源供應器之輸出 功率’雷射之溫度亦從操作位準改變成閒置位準。快速 溫度改變可產生雷射中的熱應力，已知雷射中的熱應力 會造成雷射外殼主體内的結構缺陷。 。：雷射控制器故障則雷射也會損壞。系統控制器ι〇 知壞可能突然地關閉雷射電源供應器12。因此，此類型 的事件亦可產生雷射外殼主體中的熱應力。 二其他領域亦可於製造或其它製程期間(例如修補及測 試)使用固態雷射。當使用固態雷射，例如高功率固態雷 射’於如此製程期間’處理系統可能發生非計畫與異常 事件’造成雷射控制器停止運作且過早地關閉。固態雷 射瞬間關閉可於雷射料上造成熱應力，結果為可料 致雷射效率降低或雷射無法操作之内部缺陷。在雷射無 法操作之前該等㈣缺陷之積聚劣化#射效率且需要修 訂製程處方。 / 因此’需要在非計畫與異常事件期間改善固態雷射之 功率變異的控制’以減低及/或避免雷射部件上的熱應力 (結果為導致雷射效率降低及雷射無法操作之 陷）。 ' 【發明内容】 制雷射之系統、裝 本發明之實施例大致上提供用於控 201242197 置及方法。在一個實施例中，系統包含控制器、斜坡產 生器及硬體保護系統，該控制器用以控制雷射，該斜坡 產生器用以將傳至該雷射之功率斜坡下降，該斜坡產生 器與該控制器電性耦合且可與該雷射耦合，該硬體保護 系統與該斜坡產生器電性耦合，其中該斜坡產生器監控 自該控制器與該硬體保護系統傳送至該斜坡產生器之訊 號’以债測訊號失效’且根據訊號失效偵測該斜坡產生 器將傳至該雷射之功率斜坡下降。 在一個實施例中，方法包含以下步驟：從用於雷射之 控制器傳送控制狀態訊號至斜坡產生器，監控該控制狀 態訊號之遺失脈衝，從硬體保護系統傳送硬體互鎖狀態 訊號至該斜坡產生器，監控該硬體互鎖狀態訊號之訊號 失效及^偵測到遺失脈衝或訊號失效，將傳至該雷射 之功率斜坡下降。 【實施方式】 本發明之實施例提供在造成雷射系統過早關閉之非計 畫與異常事件期間改善固態雷射之控制。高功率固態雷 射之可靠度可部份取決於在快速、無法控制的功率變異 期間引起的熱應力。未受控制的功率變異通常由於功率 =控制損失而發生。熱應力可在雷射主體中產生結構缺 陷，例如破裂。在由里杳b 心η _事件造成的無法控 制的功率變異期間積聚缺陷劣化雷射效率盘壽命。 本發明之實施㈣測可能造成無法控制的功率變異之 6 201242197 雷射規格所定義）雷射201242197 VI. Description of the Invention: TECHNICAL FIELD OF THE INVENTION Embodiments of the present invention generally relate to control of solid state lasers. More specifically, embodiments of the present invention relate to methods for shutting off solid state lasers during anomalous events. [Prior Art] Solid-state lasers have many applications in various fields. For example, solid state lasers can be used during substrate processing for the fabrication of integrated circuit devices, thin film transistor devices, flexible substrate applications, organic light emitting diodes, and solar cell devices. One application of solid state lasers is the rapid thermal annealing of substrates used in the fabrication processes of various devices. Figure 1 illustrates the schematic of a laser based annealing system for substrate processing. The laser-based substrate annealing system includes a system controller 1 , a laser power supply 12 , a laser 13 , and a hardware protection system a . The laser 13 includes a laser housing body and is located in the housing body to generate a lightning The necessary components of the beam 14. A portion of the substrate 15 or substrate 15 may be annealed by the laser beam 14 using a laser based annealing system. The system controller 1 generates a control signal 17 to set the output current or power of the laser power supply 12 to have a laser current control signal 9. By varying the operating current or power of the laser, the controller sets the energy of the laser beam 14 and thus sets the annealing temperature of the substrate 15. If a system failure occurs during wafer processing, the hardware protection system 16 turns off the laser power supply 12 by changing the state of the interlock signal 18 from turning on (〇 > 〇 to off (〇 ff) 201242197. Power supply i2 removal = signal 18 abruptly discharges the laser current signal 9 (and therefore the laser power) to zero. Since the laser temperature depends on the output power of the laser power supply 'the temperature of the laser is also The operating level changes to an idle level. Rapid temperature changes can produce thermal stresses in the laser. Thermal stresses in known lasers can cause structural defects in the body of the laser housing. It can also be damaged. The system controller may suddenly turn off the laser power supply 12. Therefore, this type of event can also generate thermal stress in the body of the laser housing. 2. Other fields can be manufactured or otherwise processed. Solid-state lasers are used during periods (such as repairs and tests). When using solid-state lasers, such as high-power solid-state lasers, 'the processing system may experience unplanned and anomalous events during this process' causing laser control The device stops operating and shuts down prematurely. The solid state laser is instantly turned off to cause thermal stress on the laser material, resulting in a decrease in laser efficiency or an inability to operate the laser. This is not possible before the laser can be operated. (d) Accumulation of defects, degradation efficiency, and the need to revise the process recipe. / Therefore 'need to improve the control of the power variation of solid-state lasers during non-planning and anomalous events' to reduce and/or avoid thermal stress on the laser components ( As a result, the laser efficiency is lowered and the laser is inoperable. [Invention] The system for manufacturing a laser, and the embodiment of the present invention are generally provided for controlling the 201242197 method. In one embodiment, The system includes a controller, a ramp generator for controlling the laser, and a hardware generator for ramping down the power transmitted to the laser, the ramp generator being electrically coupled to the controller and Coupled with the laser, the hardware protection system is electrically coupled to the ramp generator, wherein the ramp generator is monitored from the controller and the hardware protection system The signal to the ramp generator 'deactivates with the debt signal' and according to the signal failure detection, the ramp generator will ramp down the power transmitted to the laser. In one embodiment, the method comprises the following steps: The controller transmits a control status signal to the ramp generator, monitors the lost pulse of the control status signal, and transmits a hardware interlock status signal from the hardware protection system to the ramp generator to monitor the signal of the hardware interlock status signal. Failure and detection of a missing pulse or signal failure reduces the power ramp to the laser. [Embodiment] Embodiments of the present invention provide improvements during non-planning and anomalous events that cause the laser system to shut down prematurely. Control of solid-state lasers. The reliability of high-power solid-state lasers can depend in part on thermal stresses caused during fast, uncontrollable power variations. Uncontrolled power variations typically occur due to power = loss of control. Thermal stress can create structural defects, such as cracks, in the laser body. Accumulation of defect-degraded laser efficiency disk life during uncontrollable power variations caused by the ηb heart η event. Implementation of the present invention (4) Measurement of a power variation that may cause uncontrollable power 6 defined by the 201242197 laser specification)
該監控系統可包含系統控制器2 〇、 事件且提供在可控制的速率下（由 之受控制的斜坡下降。異常事件 閉、雷射失去控制或是處理期間： 示既之不意圖，該基 發明之實施例的監控 雷射23及監控系統， 硬體保護系統26、斜 坡產生器21及雷射電源供應器22。雷射23包含雷射外 殼主體及在該外殼主體内、用以產生雷射光束24(雷射 光束24用以退火基板25)之必要部件。 控制器20產生兩個訊號：雷射功率控制訊號27及控 制器狀態訊號（controller status signal)3卜雷射功率控制 訊號27提供雷射電源供應器22之電流設定點，控制器 狀態訊號3 1提供控制器20之控制狀態。因此，控制器 狀態訊號3 1提供確認控制器2〇之正常功能。此控制器 狀態訊號可為具有預定的振幅及頻率之訊號。斜坡產生 器21亦提供斜坡產生器狀態訊號3〇至系統控制器2〇。 斜坡產生器21分析控制器狀態訊號3丨與硬體互鎖狀 態 ifl 號（hardware interlock status signal)28。若控制 3| 狀 態訊號3 1與硬體互鎖狀態訊號28兩者皆出現，則斜坡 產生器使雷射功率控制訊號27通過成為斜坡產生器輸 出訊號32,斜坡產生器輸出訊號32傳至雷射電源供應 器22而不改變。 斜坡產生器2 1之工作控制程式如下所示：IF (控制器 201242197 狀態訊號3i = TRUE) AND (硬體互鎖狀態訊號28 = TRUE) THEN斜坡產生器輸出訊號32的值等於雷射功率 控制sfl號27(輸入訊號）的值且斜坡產生器狀態訊號 的值為1。若訊號3i或訊號28中之任一訊號表true， 則斜坡產生器21將斜坡產生器輸出訊號32的值以預定 速率斜坡下降至零，藉此斜坡下降至雷射的功率，且斜 坡產生器狀態訊號3 0的值為〇。 在正常的條件下，提供雷射電源供應器設定點的斜坡 產生器輸出訊號32與雷射功率控制訊號（控制器輪出）27 相同。雷射電流訊號29正比於控制器設定點訊號（雷射 功率控制§fl號）27，且系統如第]圖中所示運作，亦即， 雷射功率控制訊號27控制電源供應器電流猶如斜坡產 生器21並非系統之部件。第3圖中所示圖形之區域ι 繪示於此類型操作期間雷射電流之正常製程控制。 在異常條件的情況下，亦即，若（控制器狀態訊號31 = false) OR (硬體互鎖狀態訊號28 oalse)，則斜坡產 生益21將斜坡產生器輸出訊號32的值斜坡下降，且因 此以預定速率斜坡下降雷射電流訊號29(且因此雷射電 流位準與功率）至零位準1 3圖中所示圖形之區域H 繪不失效事件及對應的雷射電流輸出訊號29斜坡下 降，且因此雷射電流位準及/或雷射功率（斜坡下降）。 換句話說，斜坡產生器21監控自控制器2〇與硬體保 護系統26傳至斜坡產生器21的訊號，例如控制器狀態 汛號3 1與硬體互鎖狀態訊號28，以偵測訊號失效，且 201242197 根據訊號失效偵測’斜坡下降傳至雷射23的功率。訊號 失效偵測可包含偵測來自從控制器20傳送至斜坡產生 益21的控制狀態sfl ϊ虎3 1的遺失脈衝或偵測來自硬體互 鎖狀態訊號2 8的訊號失效，例如，從硬體保護系統2 6 傳至斜坡產生器21的硬體互鎖狀態訊號28 = FALSE。 為了實施先前所述之雷射控制系統，如第4圆中所繪 示’本發明之實施例可包含系統控制器2〇、硬體保護系 統26、斜坡產生器21、雷射電源供應器22及雷射23。 為了 k供斜坡產生器21之咼可靠度操作，使用僅有硬 體的方式。為了消除於正常模式（第3圖中區域I)與斜坡 下降模式（第3圖中區域II)間切換期間斜坡產生器輸出 訊號32之任何偏離，斜坡產生器21可包含由運算放大 器45、電容器46及第二電阻器48所形成的積分器。該 積分器與控制器20為電性可耦合的。第二電阻器“與 運算放大器45以串聯電性耦合，且電容器46與運算放 大器45以並聯電性耦合。反相器41恢復經由運算放大 器45所反相的雷射功率控制訊號（輸入訊號之極 性。反相器41與雷射23為電性可耦合的。 斜坡產生益21亦可包含第一電阻器47、邏輯模組43 及遺失脈#Η貞測器42，第—電阻器47與積分器可以並 聯電性耦合，邏輯模組43與硬體保護系統％及控制器 20電挫耦σ ’遺失脈衝偵測器42與控制器及邏輯模 組43電性耦合。斜坡產生器21亦可包含電壓參考50、 第接觸點40及第二接觸點49，電塵參考與積分器 201242197 ^ °耦σ的，第—接觸點40使第一電阻器47與積 。。： '連接或不連接’第二接觸點49使積分器與控制 -2〇或是電壓參彳5〇電性連接。透過第二接觸點49 積分器與控制器20為電性可輕合的，且邏輯模組杓控 制第一接觸點40與第二接觸點49兩者。 ^在雷射控制與監控開始時’控制器20發送控制器狀態 '至斜坡產生器21’例如至為斜坡產生器21之部 件丄遺失脈衝偵測器42。控制器狀態訊號31包含具有 的振^及頻率之脈衝。斜坡產生器21中之遺失脈衝 貞、丨器42尋找且偵測控制器狀態訊號31中之遺失脈 衝右/又有偵測到遺失脈衝，則遺失脈衝偵測器42將輸 出訊號5 1叹定於狀態TRUE。若由硬體保護系統26所 傳送的硬體互鎖狀態訊號28亦具有狀態TRUE，則邏輯 :組43執仃以下：”傳送回斜坡產生器狀態訊號30 -操作」或「1」，及2)以第一接觸點4〇並聯連接第一 電阻器47與電容器46。第一接觸點40受邏輯模組43 控制。因此，透過第一接觸點4〇，第一電阻器47與積 分器可以並聯電性耦合。 因此，運算放大器45開始工作作為反相放大器。因為 第一電阻器47與第二電阻器48之值為相同，故運算放 大器45之增益為負i。反相器41恢復斜坡產生器輸出 訊號32之極性。斜坡產生器輸出訊號32與來自系統控 制器2 0的雷射功率控制訊號2 7相同。 若遺失脈衝偵測器42偵測到控制器狀態訊號3 1中之 10 201242197 遺失脈衝或右硬體互鎖狀態訊號28具有FALSE值，代 號失效，則邏輯模組43切換第一接觸點40與第二 接觸點49 停止傳送回斜坡產生器狀態訊號，如第 圖中所不。現在第—電阻器47不與電容器46並聯連 運算放大器45工作作為積分器。該積分器之輸入與 田射功率控制27纟連接且該帛分器之輸入連接至 電壓參考50。換句話說，邏輯模組43將第二接觸點49 從與雷射功率控制訊號27連接切換成與電壓參考連 接而第一接觸點40從關閉的、連接的位置切換成開放 的、未連接的位置。因此，電壓參考5〇與積分器為電性 可輕合的。 電壓參考50相對於雷射功率控制訊?虎27極性而反 相，且因此自雷射功率控制訊號27之最後值減去。積分 器及因此斜坡產生器輸出訊號32如第3圖之區域^中 所示開始斜坡下降雷射電流及/或功率。為了消除由於功 率關閉事件之雷射熱應力，一旦發生功率損失的情況 下雷射電源供應器22儲存足夠能量以斜坡下降雷射電 流及/或功率 若除了控制器失效以外發生其他失效，則監控系統將 斜坡下降㈣且控带j器將移動部件進入易於#取位置。 若發生控制器失效，則將遵循以雷射功率斜坡直接關閉 系統。 雖然已描述有關於於積體電路製造期間用》處理基板 之基板退火系統的本發明之實施例，但本發明之實施例 201242197 亦可用於其他使用雷射的領域，例如在連續電流模式下 工作的固態雷射。可使用連續電流模式雷射的其他領域 可包含，例如，焊接或蒸鍍系統。 雖然前述是針對本發明之實施例，但在不脫離本發明 之基本範疇的情況下，可設計本發明之其他及進一步實 施例，且該本發明之範疇取決於以下的申請專利範圍。 【圖式簡單說明】 因此，以此方式本發明之以上描述特徵結構可詳細瞭 解，簡要總結如上的本發明之更特定描述，可參考實施 例得到，該等實施例之一些實施例繪示於附加圖式中。 然而，應注意到，附加圖式僅繪示本發明之典型實施例， 且因此並非視為限制本發明之範疇，基於本發明可承認 其他同等有效的實施例。 第1圖為基於雷射的退火系統之示意圖。 第2圖為根據本發明之實施例基於雷射的退火系統之 示意圖。 第3圖繪示呈現在正常製程期間雷射電流對於時間及 在失效事件期間的斜坡下降的圖形。 第4圖繪示根據本發明之實施例基於雷射的退火系統 之電路圖。 第5圖繪示根據本發明之實施例基於雷射的退火系統 之電路圖。 【主要元件符號說明】 12 201242197 9 雷射電流控制訊號 12 雷射電源供應器 14 雷射光束 16 硬體保護系統 18 互鎖訊號 21 斜坡產生器 23 雷射 25 基板 27 雷射功率控制訊號/ 控制器設定點訊號 29 雷射電流訊號 31 控制器狀態訊號 40 第一接觸點 42 遺失脈衝偵測器 45 運算放大器 47 第一電阻器 49 第二接觸點 51 輸出訊號 系統控制器 雷射 基板 控制訊號 系統控制器 雷射電源供應ι§ 雷射光束 硬體保護系統 硬體互鎖狀態訊號 斜坡產生器狀態訊 號 斜坡產生器輸出訊 號 反相器 邏輯模組 電容器 第二電阻器 電壓參考 13The monitoring system can include system controllers 2, events and provide at a controlled rate (slope down controlled by it. Abnormal event closure, laser loss of control, or processing: indication of the intent, the base The monitoring laser 23 and monitoring system, the hardware protection system 26, the ramp generator 21 and the laser power supply 22 of the embodiment of the invention. The laser 23 includes a laser housing body and is used in the housing body to generate a lightning The necessary components of the beam 24 (the laser beam 24 is used to anneal the substrate 25.) The controller 20 generates two signals: a laser power control signal 27 and a controller status signal 3 laser power control signal 27 The current set point of the laser power supply 22 is provided, and the controller status signal 3 1 provides the control status of the controller 20. Therefore, the controller status signal 3 1 provides the normal function of confirming the controller 2. The controller status signal can be For signal having a predetermined amplitude and frequency, the ramp generator 21 also provides a ramp generator status signal 3〇 to the system controller 2〇. The ramp generator 21 analyzes the controller The signal interlock status signal 28. If the control 3| status signal 3 1 and the hardware interlock status signal 28 appear, the ramp generator enables the laser power control signal 27 By becoming the ramp generator output signal 32, the ramp generator output signal 32 is passed to the laser power supply 22 without change. The operational control program of the ramp generator 2 1 is as follows: IF (controller 201242197 status signal 3i = TRUE) AND (hard interlock status signal 28 = TRUE) The value of the THEN ramp generator output signal 32 is equal to the value of the laser power control sfl number 27 (input signal) and the value of the ramp generator status signal is 1. If the signal If any of the signal signals 3i or 28 is true, the ramp generator 21 ramps down the value of the ramp generator output signal 32 to zero at a predetermined rate, thereby ramping down to the power of the laser, and the ramp generator status signal The value of 3 0 is 〇. Under normal conditions, the ramp generator output signal 32 providing the laser power supply set point is the same as the laser power control signal (control wheel) 27. The flow signal 29 is proportional to the controller set point signal (laser power control §fl number) 27, and the system operates as shown in the figure], that is, the laser power control signal 27 controls the power supply current as if it were a slope generator 21 is not part of the system. The area ι of the graph shown in Figure 3 shows the normal process control of the laser current during this type of operation. In the case of an abnormal condition, ie if (controller status signal 31 = false) ) OR (hard interlock status signal 28 oalse), the ramp generation benefit 21 ramps down the value of the ramp generator output signal 32, and thus ramps down the laser current signal 29 at a predetermined rate (and thus the laser current level) The region H of the graph shown in the figure with power) to zero is shown as a non-failure event and the corresponding laser current output signal 29 ramps down, and thus the laser current level and/or the laser power (slope down) . In other words, the ramp generator 21 monitors the signals transmitted from the controller 2 and the hardware protection system 26 to the ramp generator 21, such as the controller status nickname 3 1 and the hardware interlock status signal 28 to detect the signal. Invalid, and 201242197 based on signal failure detection 'slope down to the power of the laser 23. The signal failure detection may include detecting a missing pulse from the control state sfl of the ramp generating benefit 21 or detecting a signal failure from the hardware interlock status signal 28, for example, from hard The body protection system 2 6 transmits the hardware interlock status signal 28 to the ramp generator 21 = FALSE. In order to implement the previously described laser control system, as depicted in the fourth circle, an embodiment of the present invention may include a system controller 2, a hardware protection system 26, a ramp generator 21, and a laser power supply 22 And laser 23. In order to operate for the reliability of the ramp generator 21, a hardware-only approach is used. In order to eliminate any deviation of the ramp generator output signal 32 during switching between the normal mode (region I in FIG. 3) and the ramp down mode (region II in FIG. 3), the ramp generator 21 may include an operational amplifier 45, a capacitor. 46 and an integrator formed by the second resistor 48. The integrator is electrically coupled to the controller 20. The second resistor "is electrically coupled in series with the operational amplifier 45, and the capacitor 46 is electrically coupled in parallel with the operational amplifier 45. The inverter 41 recovers the laser power control signal inverted by the operational amplifier 45 (input signal) The inverter 41 is electrically coupled to the laser 23. The ramp generating benefit 21 can also include a first resistor 47, a logic module 43 and a missing pulse detector 42, the first resistor 47 and The integrator can be electrically coupled in parallel, and the logic module 43 and the hardware protection system % and the controller 20 are electrically coupled to each other. The missing pulse detector 42 is electrically coupled to the controller and the logic module 43. The ramp generator 21 is also The voltage reference 50, the first contact point 40 and the second contact point 49 may be included, and the electric dust reference is coupled to the integrator 201242197^°, and the first contact point 40 causes the first resistor 47 to be integrated with the product. The second contact point 49 is connected to electrically connect the integrator to the control-2〇 or the voltage reference 5。. Through the second contact point 49, the integrator and the controller 20 are electrically lightly coupled, and the logic module杓 controlling both the first contact point 40 and the second contact point 49. At the beginning of the shot control and monitoring, the controller 20 sends the controller state to the ramp generator 21', for example, to the component of the ramp generator 21, the missing pulse detector 42. The controller status signal 31 contains the vibration and frequency. Pulse, the missing pulse 斜坡 in the ramp generator 21, the buffer 42 finds and detects the missing pulse in the controller status signal 31, and detects the missing pulse, then the lost pulse detector 42 will output the signal 5 1 sighs in the state TRUE. If the hardware interlock status signal 28 transmitted by the hardware protection system 26 also has the status TRUE, then the logic: group 43 performs the following: "Transfer back to the ramp generator status signal 30 - operation" Or "1", and 2) connect the first resistor 47 and the capacitor 46 in parallel at the first contact point 4?. The first contact 40 is controlled by the logic module 43. Therefore, the first resistor 47 and the integrator can be electrically coupled in parallel through the first contact point 4〇. Therefore, the operational amplifier 45 starts operating as an inverting amplifier. Since the values of the first resistor 47 and the second resistor 48 are the same, the gain of the operational amplifier 45 is negative i. Inverter 41 restores the polarity of ramp generator output signal 32. The ramp generator output signal 32 is the same as the laser power control signal 27 from the system controller 20. If the lost pulse detector 42 detects that 10 201242197 missing pulse or right hardware interlock status signal 28 of the controller status signal 3 1 has a FALSE value, the code is invalid, the logic module 43 switches the first contact point 40 with The second contact point 49 stops transmitting back to the ramp generator status signal, as shown in the figure. Now the first resistor 47 is not connected in parallel with the capacitor 46. The operational amplifier 45 operates as an integrator. The input of the integrator is connected to the field power control 27 and the input of the splitter is connected to a voltage reference 50. In other words, the logic module 43 switches the second contact point 49 from the connection with the laser power control signal 27 to be connected to the voltage reference and the first contact point 40 is switched from the closed, connected position to the open, unconnected position. Therefore, the voltage reference 5〇 is electrically coupled to the integrator. The voltage reference 50 is inverted relative to the laser power control, and is therefore subtracted from the final value of the laser power control signal 27. The integrator and thus the ramp generator output signal 32 begins ramping down the laser current and/or power as shown in the area of Figure 3. In order to eliminate the laser thermal stress due to the power shutdown event, the laser power supply 22 stores sufficient energy to ramp down the laser current and/or power in the event of a power loss, if other failures occur in addition to the controller failure, then monitoring The system will ramp down (4) and control the J to move the moving parts into the easy-to-fetch position. In the event of a controller failure, the system will be shut down directly with a laser power ramp. Although an embodiment of the present invention relating to a substrate annealing system for processing a substrate during fabrication of an integrated circuit has been described, the embodiment of the present invention 201242197 can also be used in other fields where lasers are used, such as operating in a continuous current mode. Solid state laser. Other areas in which continuous current mode lasers can be used may include, for example, soldering or evaporation systems. While the foregoing is directed to embodiments of the present invention, the invention may BRIEF DESCRIPTION OF THE DRAWINGS The above-described features of the present invention can be understood in a detailed manner, and a more general description of the present invention as outlined above can be obtained by reference to the embodiments, and some embodiments of the embodiments are illustrated in Additional graphics. However, it is to be understood that the appended drawings are merely illustrative of exemplary embodiments of the invention Figure 1 is a schematic diagram of a laser based annealing system. Figure 2 is a schematic illustration of a laser based annealing system in accordance with an embodiment of the present invention. Figure 3 is a graph showing the ramp down of the laser current versus time and during the failure event during normal processing. Figure 4 is a circuit diagram of a laser based annealing system in accordance with an embodiment of the present invention. Figure 5 is a circuit diagram of a laser based annealing system in accordance with an embodiment of the present invention. [Main component symbol description] 12 201242197 9 Laser current control signal 12 Laser power supply 14 Laser beam 16 Hardware protection system 18 Interlock signal 21 Ramp generator 23 Laser 25 Substrate 27 Laser power control signal / control Set point signal 29 laser current signal 31 controller status signal 40 first contact point 42 lost pulse detector 45 operational amplifier 47 first resistor 49 second contact point 51 output signal system controller laser substrate control signal system Controller laser power supply ι§ Laser beam hardware protection system hardware interlock status signal ramp generator status signal ramp generator output signal inverter logic module capacitor second resistor voltage reference 13