1287877 九、發明說明： 【發明所屬之技術領域】 y 本發明係有關於一種光偵測器，尤其係有關於一種 類人眼的光偵測器。 【先前技術】 國際照明委員會(CIE)在1924年對人眼視錐視覺的 反應訂出標準反應函數(峰值為555nm)，稱為光的光度 函數(photopic luminuous function)。習知之類人眼光债 測器（ambient light photo detector)係指具備有光的光度 函數頻譜反應之光偵測器，意即頻譜反應近似人眼頻譜 反應之光偵測器。 近年來，隨著顯示器以及可移動之行動通信裝置的 普及’類人眼光Y貞測器的應用逐漸受到重視。目前類人 眼光偵測器的主要應用在於環境背景光的偵測，其偵測 所得之信號經過處理後，可用於調節顯示裝置的亮度與 對比。類人眼光偵測器的應用除可讓使用者有最雈的視 覺感受，以降低眼睛的疲勞外，更可節省顯示器的電力 消耗，延長行動裝置的操作時間及顯示裝置的壽命。 習知設置有顯示器的產品，包括手機、個人數位助 理（Personal Digital Assistant, PDA)、液晶螢幕、電漿電 視，及筆記型電腦等。其中，以手機與PDA為例，現 今的流行趨勢是走向全彩的螢幕，全彩的螢幕固然可以 有更多元化的應用，但伴隨著全彩螢幕而來的問題，是 5 1287877 f , 耗電量的增加。因為隨著使用者移動，這些裝置會面臨 ' 的環境亮度變化相當大，因此需依據環境亮度的變化來 調整顯示器背光源^的功率，以提供適合人眼觀看的亮 度。此時若能藉由類人眼光偵測器來調整顯示器f光源 的功率，使其發出的光線能配合環境的亮度，這樣將可 _ 大幅減低手機或PDA的耗電量，據估計節省的電力可 Λ - 達 40%。 U 習知用於偵測環境光之類人眼光偵測器的製作，包 > 括有二種方式。其一為使用矽（Si)來製作類人眼光偵測 器，此已為大部份的廠商所採用，例如安捷倫科技公司 (AGILENT Technologies)、歐司朗公司（OSRAM)、TAOS 公司（Texas Advanced Optoelectronic Solutions)···等皆已 分別推出商品化的產品。這種方式最大的好處是具有與 後續放大器與信號處理矽晶片（Si 1C)同時整合的優 點。不過使用矽材料的問題是其會吸收紅外光，而此被 吸收的紅外光將很難被消除。為此即有人提出使.用一特 > 殊的過濾器來濾去紅外光，或使用一雙偵測器，利用兩 者所分別吸收的不同波段，並進行信號處理，藉以消除 • 紅外光。但以此種方式製作之習知類人眼光偵測器，其 .· 反應頻譜和人眼的反應頻譜間仍具有差異，對某些環境 背景光源會作出和人眼反應不同的判斷，例如若環境背 景光源是鹵素燈或電燈泡時就會造成誤判，因而限制了 其可應用的範圍。 第二種可行的作法是將類人眼光偵測器與顯示器 6 1287877 面板直接整合，亦即以非晶石夕薄膜電晶體（amorphous • silicon thin film transistor，a-Si TFT)製程製作液晶面板 時同時製作類人眼/光偵測器，或在有機發光二極體面板 中，同時用有機二極體的材料來製作類人眼光偵娜器。 雖然這種作法，在偵測位置與材料成本上都相當有利， - 但此種方法需要直接更改面板的設計，因而會牽涉到整1287877 IX. Description of the Invention: [Technical Field of the Invention] y The present invention relates to a photodetector, and more particularly to a humanoid-like photodetector. [Prior Art] The International Commission on Illumination (CIE) set a standard response function (peak 555 nm) in response to the human eye cone vision in 1924, called the photopic luminuous function. An ambient light photo detector is a photodetector that has a spectral response of a photometric function of light, meaning that the spectral response approximates the optical response of the human eye. In recent years, with the popularization of displays and mobile mobile communication devices, the application of human eye-like Y-detectors has received increasing attention. At present, the main application of the humanoid eye detector is the detection of the ambient backlight, and the detected signal is processed to adjust the brightness and contrast of the display device. In addition to allowing users to have the most visual experience, the humanoid eye detector can reduce eye fatigue, save power consumption of the display, and extend the operating time of the mobile device and the life of the display device. Products that are equipped with displays, including mobile phones, personal digital assistants (PDAs), LCD screens, plasma TVs, and notebook computers. Among them, taking mobile phones and PDAs as an example, the current trend is to go to the full-color screen. The full-color screen can have more diversified applications, but the problem with the full-color screen is 5 1287877 f. The increase in power consumption. Because as the user moves, these devices will face a considerable change in ambient brightness. Therefore, the power of the display backlight ^ needs to be adjusted according to changes in ambient brightness to provide brightness suitable for human eyes. At this time, if the power of the display f light source can be adjusted by the human eye detector, the light emitted by the display can match the brightness of the environment, which can greatly reduce the power consumption of the mobile phone or the PDA, and the estimated power saved. Can be Λ - up to 40%. U is used to detect the production of human eye detectors such as ambient light. The package > includes two methods. One is the use of bismuth (Si) to make humanoid vision detectors, which have been adopted by most manufacturers, such as AGILENT Technologies, OSRAM, and TAOS (Texas Advanced Optoelectronic Solutions). )··· etc. have introduced commercial products separately. The biggest benefit of this approach is the advantage of simultaneous integration with subsequent amplifiers and signal processing silicon (Si 1C). However, the problem with using germanium materials is that they absorb infrared light, and the absorbed infrared light will be difficult to remove. For this reason, it has been proposed to use a special filter to filter out the infrared light, or use a pair of detectors to separate the different bands absorbed by the two and perform signal processing to eliminate the infrared light. . However, the conventional humanoid eye detectors produced in this way have different differences between the reaction spectrum and the response spectrum of the human eye, and certain environmental background light sources are judged differently from the human eye, for example, if When the ambient light source is a halogen lamp or a light bulb, it can cause misjudgment, thus limiting its applicable range. The second feasible method is to directly integrate the human eye detector with the display panel of the 1 1287877 panel, that is, when the liquid crystal panel is fabricated by an amorphous silicon thin film transistor (a-Si TFT) process. At the same time, a human eye/photodetector is produced, or in an organic light emitting diode panel, a material of an organic diode is used to fabricate a humanoid photodetector. Although this method is quite advantageous in detecting the position and material cost, - this method needs to directly change the design of the panel, thus involving the whole
M . 個面板的製程。目前僅有應用於手寫面板的裝置，尚無 — 法應用到環境光的偵測。 ❿ 為了解決前述製作類人眼光偵測器之方式具有的 問題，有人提出使用無法與矽晶片或面板整合的材料， 獨立製作類人眼光偵測器。此方式係選擇吸收波段接近 人眼的材料來製作光偵測器，以力求與人眼的特性相 近。理論上來說，以此種方式製作的類人眼光偵測器， 對環境光的偵測會較為穩定與均勻，不會像以矽製作的 類人眼光偵測器般，對光源作出和人眼反應不同的判 斷。且此種方式製作的類人眼光偵測器由於使用.與人眼 • 特性極為接近的獨立物件，可以省略信號的校準與處 理，因此所需的元件數並不多，故成本較習知之類人眼 -- 光偵測器低廉。此種類人眼光偵測器和面板係分別製作 • · 而成，不需更改面板的設計，因此對於整個系統而言也 較有彈性。但目前還未找出最適合的材料，尋求適合的 材料以製作出吸收波段接近人眼的光偵測器’正是目前 所應努力達成的目標。 7 1287877 : 【發明内容】 本發明的目的係提供^種類人眼光偵測器，藉以避 免紅外光的吸收，以獲致與人眼反應頻譜峰值近似的反 應頻譜。 本發明之另一目的係提供一種構造簡單的類人眼 光偵測器，藉以降低其製造成本。 根據本發明所指出的類人眼光偵測器包括： 一基底（Substrate);M. The process of the panel. At present, only the device applied to the handwriting panel has not been applied to the detection of ambient light. ❿ In order to solve the problems associated with the manner in which the humanoid photodetector was fabricated, it has been proposed to independently produce a humanoid vision detector using materials that cannot be integrated with a silicon wafer or a panel. This method selects a material that absorbs the band close to the human eye to make a photodetector in an effort to be close to the characteristics of the human eye. In theory, the humanoid eye detector produced in this way will be more stable and uniform in detecting ambient light, and will not make the human eye to the light source like the humanoid photodetector made by 矽. The reaction is judged differently. The humanoid optical detector manufactured in this way can omit the calibration and processing of the signal due to the use of a separate object that closely matches the characteristics of the human eye. Therefore, the number of components required is not large, so the cost is relatively low. Human eye - the light detector is inexpensive. This type of human eye detector and panel are made separately, without changing the design of the panel, so it is more flexible for the entire system. However, it has not yet been found that the most suitable material, and the search for suitable materials to produce a photodetector with an absorption band close to the human eye is exactly what it is currently trying to achieve. 7 1287877: SUMMARY OF THE INVENTION The object of the present invention is to provide a human eye detector that avoids the absorption of infrared light to obtain a response spectrum that approximates the peak spectrum of the human eye response spectrum. Another object of the present invention is to provide a humanoid optical detector that is simple in construction, thereby reducing its manufacturing cost. The humanoid optical detector according to the present invention comprises: a substrate (Substrate);
一緩衝層（Buffer layer)，其係形成於該基底上； 一吸收層（Absorption layer)，其係形成於該緩衝層 上，用以吸收人眼可視波長範圍之可見光，且 該吸收層的材料係為砷化鋁鎵；以及 一濾光層（Filter layer)，其係形成於該吸收層上， 用以濾去紅外光，且該濾光層之材料係為砷化 鎵，且其能隙低於該吸收層。 月，J迅，作為吸收層材料 ， 1 ^ \ I Tpj pi w J 〒、Λa buffer layer formed on the substrate; an absorption layer formed on the buffer layer for absorbing visible light in a visible wavelength range of the human eye, and the material of the absorption layer Is a gallium arsenide; and a filter layer formed on the absorbing layer for filtering infrared light, and the material of the filter layer is gallium arsenide, and the energy gap thereof Below the absorption layer. Month, J Xun, as the material of the absorbing layer, 1 ^ \ I Tpj pi w J 〒, Λ
AlxGai_xAs之化學分子式表示，其中〇<χ< 本發明將藉由參考下列的實施方式做進一步 明’這些實施方式並不限制本發明前面所揭示之内容5兄 熟習本發日以技藝者，可做些許之改良與 脫離本發明之範轉。 1 一仍不 【實施方式】 明 > 閱第-圖’本發明的類人眼光伯測器包括—基 8 1287877 底（Substrate)2、一形成於該基底2上之緩衝層（Buffer • layer)4、一形成於該緩衝層4上，用以吸收人眼之可見 〆 光之吸收層（Absorption layer)6，以及一形成於該吸收層 6上，用以濾去紅外光之濾光層（Filter layer)14。辞濾光 層可做為接觸層。 ^ 其中，該吸收層 6 係為 PIN((P-type-Intrinsic-N-type)) • 光偵測器元件，其進一步包含一第一吸收次層8、一第 _ 二吸收次層10及一第三吸收次層12，依序形成於該緩 • 衝層4上，亦即該第一吸收層8係與該缓衝層4直接接 觸。構成該吸收層6的材料係為砷化鋁鎵，其可以 AlxGai_xAs之化學分子式表示，其中0<χ<1，較佳為 0·2<χ<0·8，更佳為0·4<χ<0·65。另外，上述構成該濾光 層14之材料係為神化嫁。 前述之該濾光層14與該基底2係可分別為Ρ型或 Ν型換雜，但兩者需為不同型。此外，前述之第一吸收 次層8與第三吸收次層12分別為Ρ型或Ν型摻雜，但 * 兩者為不同型。另外，第三吸收次層12與濾光屠14需 為同型，且基底2、緩衝層4與第一吸收次層8需為同 -— 型，而第二吸收次層10為無摻雜。例如，當基底2為 _， Ν型時，第一吸收次層8為Ν型，而第三吸收次層12 與濾光層14皆為Ρ型；反之，當基底2為Ρ型時，則 第一吸收次層8為Ρ型，而第三吸收次層12與濾光層 14則皆為Ν型。另外，本發明的類人眼光偵測器中， 該濾光層14與該基底2均係為偏壓電極的接觸平面。 9 1287877 ♦ 本發明之類人眼光偵測器中，由於濾光層14的能 • 隙較吸收層6為小，·所以該濾光層14吸收的光子所產 生的少數載子會被/兩者間的能隙差所阻隔，因此不會轉 換成光電流，僅有該吸收層6吸收之光子所產生的載子 能轉換成光電流。另外’由於光子的波長越短時，越易 。 被濾光層14所吸收，且光子所能穿透之濾光層14的厚 .~ 度越薄。因此，若增加該濾光層14之厚度，將使到達 3亥吸收層6的光變少’且短波長光的減少會較長波長光 φ 更嚴重。因此濾光層14厚度的增加除了會使本發明類 人眼光偵測器的反應度降低之外，其反應度頻譜峰值也 會向紅外線的波長區域移動（紅移）。反之，若該濾光層 14之厚度較薄時，則到達吸收層6的光將會變多，這 會使得本發明類人眼光偵測器的反應度變大，且其反應 度頻譜會向紫外線區域移動（藍移）。由此可得知該濾光 層14的厚度會影響本發明類人眼光偵測器的反應頻譜 峰值的位置及其反應度的大小。因此為使本發明類人眼 • 光偵測器可獲致與人眼反應頻譜峰值近似的反應頻 譜，該濾光層14的厚度較佳為0.05〜0·4μπι，更佳為 ， 0.1 〜〇·2μηι，最佳為 〇·12〜0·15μπι。 f施例一 在此藉由習知蟲晶成長（epitaxial growth)的方式， 先形成一 N型摻雜之砷化鎵(GaAs)基板。之後，在於基 板上形成一厚度為100 nm、濃度為l〇18/cm3之N型摻 1287877 雜的砷化鎵（GaAs)緩衝層。接著在缓衝層上形成吸收 層，吸收層分為三層，，分別係第一吸收次層、第二吸收 次層及第三吸收次層。第一吸收次層之厚度係為 2〇Onm，其材料係AlxGabxAs，x=0.53，且為濃度是 1018/cm3之N型摻雜；第二吸收次層之厚度係為 300nm，材料係AlGaAs ;第三吸收次層之厚度係為 200nm，材料係AlGaAs，且為濃度是1018/cm3之P型 推雜。最後在吸收層上形成120〜150nm厚的濾、光層， 其材料係砷化鎵(GaAs)，且為濃度是1018/cm3之P型摻 雜。藉此即可製成本發明的類人眼光偵測器，在此以 Al〇.53Ga〇.47As類人眼光偵測器稱之。 製作出Al0.53Ga0.47As類人眼光偵測器後，對其光 頻譜反應進行量測，光頻譜反應的量測係在探針測試台 上進行，以 200W 之氙氣燈（Xenon Lamp)(ASB-XE-175EX)當作量測之光源，光源經過兩組 透鏡的聚焦在經過頻率設定為250Hz之斷波器（chopper) 作調變之後，進入到SPEX 500M分光儀，藉以將入射 的光源分成單調光，以使前述光偵測器得以吸收不同波 長的光，藉以產生大小不同之光電流。之後，將產生的 光電流經由電流放大器（Standford Research SR570)將訊 號放大並且轉成電壓訊號，再藉由鎖向放大器 (Standford Research SR530)處理後，以讀出光偵測器送 出之訊號的數值。 為了要得到光偵測器樣品的反應度值，在此將光偵 1287877 ▲ 測器樣品以標準矽光偵測器（Newport 818UV)進行校 • 正，藉此即可得到本,發明之類人眼光偵測器樣品的反應 度頻譜(Rpd)。由於/兩種光偵測器吸收受光面積相等， 所以經由標準矽光偵測器校正，即可正確地量得;^發明 之類人眼光偵測器樣品的絕對反應度。在量測反應頻譜 - 時，將電流放大器設定在負偏壓2V，靈敏度=ι μΑ/ν。 . Al〇.53Ga().47As類人眼光偵測器經量測所得結果顯 • 示，其光頻譜反應之峰值為556·5ηιη，峰值反應度為〇.〇5 # A/W，半寬為 104nm。The chemical formula of AlxGai_xAs is indicated, wherein 〇<χ< The invention will be further clarified by reference to the following embodiments. These embodiments do not limit the content disclosed in the foregoing disclosure of the present invention. Make some improvements and departures from the invention. 1 is still not [Embodiment] Ming > Figure - Figure 'The humanoid eye detector of the present invention includes a base 8 1287877 Substrate 2, a buffer layer formed on the substrate 2 (Buffer • layer 4, an absorption layer 6 formed on the buffer layer 4 for absorbing visible light of the human eye, and a filter layer formed on the absorption layer 6 for filtering out infrared light (Filter layer) 14. The filter layer can be used as a contact layer. Wherein the absorbing layer 6 is a PIN ((P-type-Intrinsic-N-type)) • photodetector element, further comprising a first absorption sub-layer 8, a second absorption sub-layer 10 and A third absorption sub-layer 12 is sequentially formed on the buffer layer 4, that is, the first absorption layer 8 is in direct contact with the buffer layer 4. The material constituting the absorbing layer 6 is aluminum gallium arsenide, which can be represented by the chemical formula of AlxGai_xAs, wherein 0 < χ < 1, preferably 0·2 < χ < 0·8, more preferably 0·4 < χ <;0·65. Further, the material constituting the filter layer 14 described above is a deified marriage. The filter layer 14 and the substrate 2 described above may be respectively of a Ρ type or a Ν type, but the two need to be different types. Further, the first absorption sub-layer 8 and the third absorption sub-layer 12 are respectively doped with a Ρ-type or Ν-type, but * are different types. In addition, the third absorption sub-layer 12 and the filter absorber 14 need to be of the same type, and the substrate 2, the buffer layer 4 and the first absorption sub-layer 8 need to be of the same type, and the second absorption sub-layer 10 is undoped. For example, when the substrate 2 is _, Ν type, the first absorbing sub-layer 8 is Ν-type, and the third absorbing sub-layer 12 and the filter layer 14 are both Ρ-type; otherwise, when the substrate 2 is Ρ-type, then The first absorption sub-layer 8 is of a Ρ type, and the third absorption sub-layer 12 and the filter layer 14 are both Ν-shaped. In addition, in the human eye photodetector of the present invention, the filter layer 14 and the substrate 2 are both contact planes of the bias electrodes. 9 1287877 ♦ In the human eye detector of the present invention, since the energy gap of the filter layer 14 is smaller than that of the absorption layer 6, a minority carrier generated by the photon absorbed by the filter layer 14 will be/two The energy gap between the two is blocked, so that it is not converted into a photocurrent, and only the carrier generated by the photons absorbed by the absorption layer 6 can be converted into a photocurrent. In addition, the shorter the wavelength of the photon, the easier it is. It is absorbed by the filter layer 14, and the thickness of the filter layer 14 through which the photons can pass is thinner. Therefore, if the thickness of the filter layer 14 is increased, the light reaching the 3 absorbing layer 6 will be made smaller, and the decrease of the short-wavelength light will be more severe for the longer-wavelength light φ. Therefore, in addition to the increase in the thickness of the filter layer 14 in addition to the decrease in the reactivity of the human eye photodetector of the present invention, the peak of the reactivity spectrum also shifts to the wavelength region of the infrared light (red shift). On the other hand, if the thickness of the filter layer 14 is thinner, the amount of light reaching the absorbing layer 6 will increase, which will make the reactivity of the humanoid photodetector of the present invention larger, and the spectrum of the reaction will be ultraviolet ray. Area movement (blue shift). It can be seen that the thickness of the filter layer 14 affects the position of the peak of the reaction spectrum of the humanoid photodetector of the present invention and the degree of its reactivity. Therefore, in order for the human eye-like photodetector of the present invention to obtain a reaction spectrum similar to the peak of the human eye response spectrum, the thickness of the filter layer 14 is preferably 0.05 to 0. 4 μm, more preferably 0.1 to 〇. 2μηι, the best is 〇·12~0·15μπι. f Example 1 Here, an N-doped gallium arsenide (GaAs) substrate is first formed by conventional epitaxial growth. Thereafter, an N-type doped 1287877 impurity gallium arsenide (GaAs) buffer layer having a thickness of 100 nm and a concentration of 10 〇 18/cm 3 was formed on the substrate. Next, an absorbing layer is formed on the buffer layer, and the absorbing layer is divided into three layers, which are a first absorbing sublayer, a second absorbing sublayer, and a third absorbing sublayer, respectively. The thickness of the first absorption sublayer is 2〇Onm, the material is AlxGabxAs, x=0.53, and is N-type doping with a concentration of 1018/cm3; the thickness of the second absorption sub-layer is 300 nm, and the material is AlGaAs; The third absorption sublayer has a thickness of 200 nm, the material is AlGaAs, and is a P-type dopant having a concentration of 1018/cm3. Finally, a filter layer of 120 to 150 nm thick is formed on the absorption layer, and the material thereof is gallium arsenide (GaAs), and is a P-type doping having a concentration of 1018/cm3. Thereby, the humanoid photodetector of the present invention can be made, and is referred to herein as an Al〇.53Ga〇.47As human eye photodetector. After the Al0.53Ga0.47As human eye detector was fabricated, the optical spectrum response was measured. The measurement of the optical spectrum reaction was performed on the probe test bench with a 200W xenon lamp (ASB). -XE-175EX) As a light source for measurement, the light source is focused by two sets of lenses and modulated by a chopper with a frequency of 250 Hz. After entering the SPEX 500M spectrometer, the incident light source is divided. Monotonic light is used to enable the aforementioned photodetector to absorb light of different wavelengths, thereby generating photocurrents of different sizes. After that, the generated photocurrent is amplified by a current amplifier (Standford Research SR570) and converted into a voltage signal, and then processed by a lock-in amplifier (Standford Research SR530) to read the value of the signal sent by the photodetector. . In order to obtain the responsiveness value of the photodetector sample, the photodetector 1287877 ▲ detector sample is calibrated with a standard neon detector (Newport 818UV), thereby obtaining the present invention. The reflectance spectrum (Rpd) of the eye detector sample. Since the two types of photodetectors absorb the equal light receiving area, they can be accurately measured by standard photodetector calibration; the absolute reactivity of the human eye detector sample of the invention. When measuring the response spectrum -, set the current amplifier to a negative bias of 2V with sensitivity = ι μΑ / ν. The measured results of the Al〇.53Ga().47As human eye detector showed that the peak of the optical spectrum response was 556·5ηιη, and the peak response was 〇.〇5 # A/W, half width. It is 104 nm.
Al〇.53Ga〇.47As類人眼光偵測器的反應度頻譜在正 規化之後，與國際照明委員會之光的光度函數作比較， 結果請參閱第二圖。 從弟，一圖中可以看到’ Alo.53Gao.47As類人眼光偵測 器的反應度頻譜與國際照明委員會之光的光度函數極 為接近。 【圖式簡單說明】 第一圖本發明之類人眼光偵測器元件的剖面圖；以及 第二圖本發明之類人眼光偵測器元件反應度頻譜和國 際照明委員會（CIE)光的光度函數之比較的示 意圖。 【主要元件符號說明】 2 基底 12 1287877 4 緩衝層 6 吸收層 8 第一吸收次層 10第二吸收次層 12第三吸收次層 14濾光層The reactivity spectrum of the Al〇.53Ga〇.47As human eye detector is compared with the photometric function of the International Commission on Illumination after normalization. See Figure 2 for the results. From the younger brother, you can see that the response spectrum of the 'Alo.53Gao.47As human eye detector is very close to the photometric function of the light of the International Commission on Illumination. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a human eye detector component of the present invention; and a second diagram of the human eye detector component reactivity spectrum of the present invention and the luminosity of the International Commission on Illumination (CIE) light. A schematic diagram of the comparison of functions. [Main component symbol description] 2 Substrate 12 1287877 4 Buffer layer 6 Absorbing layer 8 First absorption sublayer 10 Second absorption sublayer 12 Third absorption sublayer 14 Filter layer