1240424 九、發明說明： 【發明所屬之技術領域】 本發明係為一種致電吸来 兒及九凋制态，特別是本發明利 猫日日層結構為 p，j + , P 丨（MQW)-n -i (collector)-n 之 P丨n卜n蟲晶層成長在—丰導雕装4c u 信調制器。 基板上，可應用於光通 【先前技術】 1〇二，今高速的光通信系、統中，在速度大於 一，S’SeC)之光電調制器為通信系統中非常麵 /刀。現今使用之光電調制器最主要分為兩類，分別 (electro-absorption modulator^ EAM)和致電_光折變式調制器（日dr〇_〇pth 0 ulatof E0M)。而習用之致電吸光調制器因其介入 抽耗太大，το件阻抗過低，無法作為高性能的行波式光 電調制器。 石:芩閱『第5圖』所示，係習用之致電吸光調制器 勺职日日、、、口構tf思、圖。如圖所示：習帛之致電吸光調制器 观的曰曰層、结構為—Ρ-μη的蠢晶層結構H P摻雜 2本貝層及—η摻雜層由上而下成長於基板上，該本 :1 (i:ayer)為一 MQW的結構用來吸收入射光，外加 ，場也會侷限在該本質層中以利調制'然而該p小η的遙 晶層結構最大的問題就是在於其為了降低操作電壓，該 1240424 本質層（Mayer)的厚度不能太厚，然而薄的本 丨 卻會有相當大的元件電容’會造成元件速度^現 的劣化’和非理想的微波傳播效應，雖可利用加厚吸光 層或縮小元件幾何尺寸的方法來降低系統電容以增大元 件阻抗和微波速度，但會造成光信號g:合的困難和介入 損耗的增加。 J Λ 1240424 【發明内容】 因此’本發明之主要目的係在於解決驅動電壓和速 度之間的trade-off(牴觸）及增加了光在非換雜區之偈限 係數（confinement factor)，並降低了光在摻雜區因自由 載波吸收（free-carrier_absorpt丨〇n )所造成的介入損耗。 為達上述之目的，本發明係提供一種致電吸光調制 器係由一 p-i-n- i-η磊晶層成長在一半導體基板上，該 Ρ-ι-η - i-η磊晶層係由一 p型摻雜層、一第一本質層、一 η型摻雜層、一第二本質層及一第二〇型摻雜層磊 晶成長形成，藉此形成一致電吸光調制器。本發明之致 電吸光调制為，其磊晶層結構為口_丨_ (MQw)_n+_i (coMect〇r)-n，由於在無摻雜的空乏層加入該第一 n型摻 雜層，作為電場分配層，讓大部分的電場集中在該第一 本夤層〔i-layer ( MQW)〕，使得驅動電壓不會隨著該第 一本質層（集電极）〔j-layer ( collector)〕厚度的增加而 增加，解決了驅動電壓和速度之間的牴觸及增加了光在 非摻雜區之侷限係數，並降低了光在摻雜區因自由載波 吸收所造成的介入損耗。 【實施方式】 請參閱『第1 A〜1 β圖』所示，係本發明之致電 及光X»周制器的蟲晶結構示意圖、本發明之致電吸光調制 器示意圖。如圖所示：係由一 p_j_n- j_n磊晶層i成長在 一半導體基板2〔如：砷化鎵（GaAs)、磷化銦（|np) 1240424 及氮化鎵（GaN)或氮化鋁（AIN)、矽（Sj)及銻化鎵 C GaSb)接雜形成〕上’該p小n — j_n蟲晶層1係由一第 二本質層1 4形成於一第二η型摻雜層i 5上，一第一门 型摻雜層1 3形成於該第二本質層i 4上，一第一本質 層1 2形成於該第一 η型摻雜層1 3上，一p型摻雜層工 1形成於該第一本質層1 2上，其結構由所有的化|物 半導體〔砷化鎵（GaAs)、磷化銦（丨nP)、氮化鎵（GaN)〕 和其合金半導體〔氮化鎵鋁（A|GaN )，氮化鎵銦 (InGaN )’石申化鎵銦（inGaAs )，石申化鎵紹銦（|nAiGaAs)〕 或四族元素半導體（Si)和其合金半導體（SjGe)所形成，藉 此形成一致電吸光調制器。本發明之致電吸光調制器的 磊晶結構為M(MQW)-n+-i(C0||ect0r)_n，由於在無摻雜的 空乏層中多了一層n+5doped的第一 n型摻雜層工3，該第 “ η型摻雜層1 3之帶溝大於操作波長（丄· 5 5 μΓη)的 光子旎量，作為電場分配層，讓大部分的電場集中在該 第一本質層1 2，使得驅動電壓不會隨著該第二本質層 (集電极）〔i-layer( collector)〕1 4厚度的增加而增加， 解決了驅動電壓和速度之間的trade_〇ff(牴觸）及增加了 光在非摻雜區之侷限係數（confjnement fact〇r)，並降低 了光在摻雜區因自由載波吸收（free_carrie卜abs〇rpti()n ) 所ie成的介入損耗。該第一本質層1 2係由一砷化鎵銦/ 畔化鋁銦（InGaAs/lnAIAs )、或砷化鎵銦/磷化銦 (InGaAs/ InP)、或碟化砷鎵銦/鱗化砷鎵銦（丨nGaAsp / 1240424 lnGaAsP )、或銻化砷鎵鋁/砷化鎵銦（AIGaAsSb / lnGaAs)和銻化砷鎵鋁/銻化鎵（AIGaAsSb/GaSb)等 f質接面所形成的多重量子井或疊晶格所組成之多波長 里子：（MQW)。該多波長量子井（MQW)之帶寬為接 近於操作波長（！ .5 5 μη)的光子能量，可隨著外加電 壓的大小調整對光纖通信波長吸收的大小，並利用帶寬 為大於操作波長（1 ·5 5 pm)的光子能量之ρ型摻雜層 1 1、第二η型摻雜層丄5為光波導的上、下覆蓋層。曰 &請參閱『第2圖、表1』所示，係為使用商用模擬 軟體丨SE7·5所得之模擬結果，其it件詳細參數如表！所 =，以矽（Si)和鍺化矽（SjGe)合金為材料之累增崩 潰光二極體（SACM-APD)結構，利用nqdoped摻^層 場侷限在崩潰層中，以避免吸光層在操作時遭受^ 朋潰的問題。由於第二本質層的帶溝大於操作波長（丄. 5 5 μ m )的光子能量，不會吸收入射的光信號，可降低 凡件電容値，其元件的總電容值是由總空乏區的厚度來 、疋在線性刼f區小信號的假設下，其總電容值並不 會因為外加了 n+Sfoped的摻雜層所造成電場大小上的不 同而不同。此外，因為多了這一層厚的第二本質層（卜丨 2)，可使光在非摻雜區的偈限係數大幅增加，同時也降 低了光在摻雜區因自由載波吸收所造成的介入損耗。 明芩閱『第3圖』所示，係本發明在光纖通信波長 • 5 5 μ m )的貫施例之蠢晶結構和其對應之帶圖的示 1240424 意圖。如圖所示：其量子井為本質摻雜砷化鋁銦/砷化鎵 銦所形成之多波長量子井（丨-丨nAIAs/丨nGaAsMQW)，可 以在外加電場的情形τ吸收i 5 5 〇nm ( i 5 波長+的光子，為光波導的核心層（c〇re)。該多波長量子井 由P+和η的半導體層所包夾。其中p摻雜磷化銦包覆層 (P+InPCIaddingLayer)和η摻雜構化銦包覆層（η+|η P Cladding Layer)為光波導的上、下包覆層（daddjn⑴。 而本貝摻雜砷化鋁銦漸變帶溝集電極（HnA|As Gmded Bandgap Collector)的砷化鎵鋁銦（|nA丨GaAs)層為降 低7G件電容的非摻雜層，其漸變帶溝層（1240424 IX. Description of the invention: [Technical field to which the invention belongs] The present invention is a state of inhalation and sterilization, in particular, the structure of the daily cat layer of the present invention is p, j +, P 丨 (MQW)- The worm crystal layer of n -i (collector) -n grows in-Fengdao carved 4c u signal modulator. On the substrate, it can be applied to optical communication. [Previous technology] 102. In today's high-speed optical communication systems, the optical modulator with a speed greater than one (S'SeC) is a very facet / knife in communication systems. The photoelectric modulators used today are mainly divided into two categories, namely (electro-absorption modulator ^ EAM) and call_photorefractive modulator (day dr0_〇pth 0 ulatof E0M). However, the conventionally used light absorption modulator due to its intervention is too large and the το impedance is too low to be used as a high-performance traveling-wave optical modulator. Shi: Read the "Figure 5", which is a customary phone call absorber modulator. As shown in the figure: Xi Zhizhi calls the light absorption modulator concept of the layer, the structure of the stupid crystal layer structure of -P-μη HP doped 2 benzyl layer and -η doped layer grow on the substrate from top to bottom The book: 1 (i: ayer) is an MQW structure used to absorb incident light. In addition, the field will also be confined to the essential layer to facilitate modulation '. However, the biggest problem of the telecrystal layer structure with p small η is In order to reduce the operating voltage, the thickness of the 1240424 essential layer (Mayer) should not be too thick. However, the thin version will have a considerable component capacitance, which will cause the degradation of the element speed and the non-ideal microwave propagation effect. Although the thickness of the light-absorbing layer or the reduction of the geometrical dimensions of the component can be used to reduce the system capacitance to increase the component impedance and the microwave speed, it will cause difficulties in optical signal g and increase the insertion loss. J Λ 1240424 [Summary of the invention] Therefore, the main purpose of the present invention is to solve the trade-off between the driving voltage and the speed, and to increase the confinement factor of light in the non-mutated region, and It reduces the insertion loss caused by light in the doped region due to free-carrier absorption (free-carrier_absorpt). In order to achieve the above-mentioned object, the present invention provides a telephone light absorption modulator system grown from a pin-i-η epitaxial layer on a semiconductor substrate. The p-ι-η-i-η epitaxial layer is formed by a p A type doped layer, a first intrinsic layer, an n-type doped layer, a second intrinsic layer, and a 20-type doped layer are epitaxially grown to form a uniform electro-absorption modulator. The electro-optical absorption modulation of the present invention is such that the epitaxial layer structure is _ 丨 _ (MQw) _n + _i (coMect〇r) -n. Since the first n-type doped layer is added to the undoped empty layer, As an electric field distribution layer, most of the electric field is concentrated in the first intrinsic layer [i-layer (MQW)], so that the driving voltage does not follow the first intrinsic layer (collector) [j-layer (collector )] Increased thickness increases, solves the interference between driving voltage and speed, increases the limiting coefficient of light in the undoped region, and reduces the insertion loss of light in the doped region due to free carrier absorption. [Embodiment] Please refer to the "Figure 1 A ~ 1 β", which is a schematic diagram of the insect crystal structure of the telephone and optical X »weekly device of the present invention, and the schematic diagram of the telephone light absorption modulator of the present invention. As shown in the figure: a p_j_n- j_n epitaxial layer i is grown on a semiconductor substrate 2 [such as gallium arsenide (GaAs), indium phosphide (np) 1240424, and gallium nitride (GaN) or aluminum nitride (AIN), silicon (Sj), and gallium antimonide (CGaSb) are formed]] The p small n — j_n worm crystal layer 1 is formed by a second intrinsic layer 14 on a second n-type doped layer On i 5, a first gate-type doped layer 13 is formed on the second intrinsic layer i 4, a first intrinsic layer 12 is formed on the first n-type doped layer 13, and a p-type doped layer is formed. The heterolayer 1 is formed on the first intrinsic layer 12 and its structure is composed of all the chemical semiconductors [GaAs, GaP, nP, GaN] and alloys thereof. Semiconductor [Aluminum gallium nitride (A | GaN), indium gallium nitride (InGaN) 'indium gallium indium (inGaAs), indium gallium indium (inGaAs)] or Group IV semiconductor (Si) and its An alloy semiconductor (SjGe) is formed, thereby forming a uniform electro-absorption modulator. The epitaxial structure of the light absorption modulator of the present invention is M (MQW) -n + -i (C0 || ect0r) _n, because there is one more n + 5doped first n-type doped in the undoped empty layer Layer 3, the "n-type doped layer 13" has a band groove greater than the operating wavelength (丄 · 5 5 μΓη) of the photon chirp amount, as an electric field distribution layer, so that most of the electric field is concentrated in the first essential layer 1 2, so that the driving voltage does not increase as the thickness of the second intrinsic layer (collector) [i-layer (collector)] 14 increases, solving the trade_〇ff (牴Touch) and increase the confinement fact of light in the undoped region, and reduce the insertion loss of light in the doped region due to free carrier absorption (free_carrie and absorpti () n). The first essential layer 12 is composed of an InGaAs / InAIAs, or an InGaAs / InP, or a InGaAs / InP, a scaled arsenide. Gallium indium (nGaAsp / 1240424 lnGaAsP), or f-junctions such as AlGaAsSb / InGaAs and AIGaAsSb / GaSb Multi-wavelength neutrons composed of multiple quantum wells or stacked lattices: (MQW). The bandwidth of the multi-wavelength quantum well (MQW) is the photon energy close to the operating wavelength (! .5 5 μη), which can be added with The voltage is adjusted to absorb the optical fiber communication wavelength, and the p-type doped layer 1 and the second n-type doped layer 15 are used as optical waveguides with a bandwidth of photon energy greater than the operating wavelength (1.55 pm). The upper and lower cover layers. Please refer to "Figure 2 and Table 1" for simulation results obtained using commercial simulation software SE7 · 5. Its detailed parameters are shown in the table! Silicon (Si) and silicon germanium (SjGe) alloys are used to accumulate collapsed photodiode (SACM-APD) structures. The nqdoped doped layer field is limited to the collapsed layer to prevent the light absorbing layer from suffering during operation. Since the band gap of the second essential layer is greater than the operating wavelength (丄. 5 5 μm) of the photon energy, it will not absorb the incident optical signal, which can reduce the capacitance of all parts. The total capacitance of its components is determined by From the thickness of the total empty region, the total current is The capacitance value will not be different due to the difference in the electric field caused by the addition of the n + Sfoped doped layer. In addition, the addition of this thick second essential layer (Bu 2) can make light non-doped The threshold coefficient of the miscellaneous region is greatly increased, and at the same time, the insertion loss caused by the free carrier absorption of light in the doped region is also reduced. As shown in Figure 3, the optical fiber communication wavelength of the present invention is 5 5 μ m) The stupid crystal structure of the embodiment and its corresponding band diagram is shown in 1240424. As shown in the figure: the quantum well is a multi-wavelength quantum well (丨-丨 nAIAs / 丨 GaAsMQW) formed by essentially doped aluminum indium arsenide / indium gallium arsenide, which can absorb i 5 5 〇 in the case of an external electric field. nm (i 5 wavelength + photons) is the core layer (core) of the optical waveguide. The multi-wavelength quantum well is sandwiched by the semiconductor layers of P + and η. Among them, the p-doped indium phosphide coating (P + InPCIaddingLayer) and η-doped structured indium cladding layer (η + | η P Cladding Layer) are the upper and lower cladding layers (daddjn⑴) of the optical waveguide. The Bebe-doped aluminum indium arsenide graded band groove collector (HnA | As Gmded Bandgap Collector) is a non-doped layer that reduces the capacitance of 7G, and its graded band groove layer (
Bandgap Layer)將製造一内建電場（〜i 〇 kv/cm)，將光 激發電子在沒有外加電場的情形下仍能夠卩。ve卜sh〇〇t 的速度（4 10 cm/sec)掃除到n摻雜磷化銦包覆層（门 +丨nPCIaddingLayer) ’大幅增加元件的高功率表二 。月，閱第4 A〜4 B圖』所示，係本發明之集總 (all-l_ped)式結構的致電吸光調制器、本發明之行波 一(t_lmg-wave ) <結構的致電吸光調㈣器。如圖所 不：本發明之遙晶層結構於實際製作上，其幾何結構可 為集總式結構（基板為n摻雜|np)或行波式 板為半絕緣丨nP)。利用上述之模擬結果及該幾何結構土， =加上適當之行波式元件幾何尺寸（其主動區波導管的 寬度為2Pm ’主動區共面波導傳輸線之信號線和地線的 距離為2 _，石申化㈣/石申化鎵銦之多波長量子井和集極 10 1240424 層的厚度分別為““⑴和““⑴广可達成和習 之P I η結構的而速EAM結構相比之下，具有較大的 尤性阻W〜4 Q〇hm vs•〜2 5〇hm)，較小的光速/電速 匹配程度（1 0 % vs 3 3 %)， ^^ 她在性能上的大幅提升。、代表“速仃波式先 綜上所述，本發明之致電吸 潰光二極體及雙極電 系力日朋 ^丄0 电日日體的磊晶層結構，可改善元件雷 谷和操作電壓的3 率，降低介人損耗。及心㈣，並提升輸出功 淮以上所述者’僅為本發明之較佳實施例，告 此限定本發明實施之範圍；故，凡依本發: 錦，皆應仍屬本發簡單的等效變化與修 5天d寻利涵蓋之範圍内。 1240424 【圖式簡單說明】 ^ 圖係本發明之致電吸光調制器的磊晶結構示意 第1 B圖，係本發明之致電吸光調制器示意圖。 g 2圖，係本發明之SACM_APD結構之電場模擬比較 弟3圖’係本發明在光纖通信波長（丄·5 5⑽的實施 例之磊晶結構和其對應之帶圖的示意圖。 第4 Α圖’係本發明之集總（训_丨_㈣）式結構的致電 吸光調制器。 第4 B圖，係本發明之行波（trave丨式結構的 致電吸光調制器。 第5圖m之致電吸光調制器的蟲晶結構示意圖。 表1，係元件詳細參數表。 【主要元件符號說明】 P小η - i_n磊晶層 1 P型摻雜層 11 第一本質層 12 第一 η型摻雜層 13 第二本質層 14 第二η型摻雜層 15 半導體基板 2The Bandgap Layer) will create a built-in electric field (~ i 0 kv / cm), and the photo-excited electrons will be able to oscillate without an external electric field. The speed (4 10 cm / sec) of vebsh 〇t sweeps to the n-doped indium phosphide cladding layer (gate + nPCIaddingLayer) ′ which greatly increases the high power of the device. As shown in Figures 4A ~ 4B ", they are all-l_ped light absorption modulators of the present invention, t_lmg-wave < l1 light absorption of the present invention Tuner. As shown in the figure, the remote crystal layer structure of the present invention is actually manufactured, and its geometric structure can be a lumped structure (the substrate is n-doped | np) or the traveling wave plate is semi-insulated (nP). Using the above simulation results and the geometric structure soil, plus the appropriate travelling wave element geometry (the width of the active zone waveguide is 2Pm 'the distance between the signal line and the ground line of the active area coplanar waveguide transmission line is 2 _ , Shishenhua Gao / Shishenhua Ga Indium multi-wavelength quantum well and collector 10 1240424 layers with thicknesses of "" ⑴ "and" ⑴ ", respectively, compared with the fast-equivalent EAM structure of PI η structure that can be achieved and learned. It has a larger specific resistance W ~ 4 Q〇hm vs • ~ 2 5〇hm), a small degree of light / electricity matching (10% vs 33%), ^^ her performance Greatly improved. According to the above-mentioned "speed-wave type", the epitaxial layer structure of the electric sun-solar diode of the present invention can improve the thunder valley and operation of the device. The 3 rate of the voltage reduces the intermediary loss. And the palpitations and increase the output power. The above-mentioned 'is only a preferred embodiment of the present invention, which limits the scope of the implementation of the present invention; therefore, according to this issue: Brocade, all should still fall within the scope of the simple equivalent changes and profit-recovery of 5 days. 1240424 [Simplified illustration of the figure] ^ The figure shows the epitaxial structure of the light absorption modulator of the present invention. Figure 2 is a schematic diagram of the light absorption modulator of the present invention. Figure 2 is a comparison of the electric field simulation of the SACM_APD structure of the present invention. Figure 3 is the epitaxial structure of the embodiment of the present invention at the optical fiber communication wavelength (丄 · 5 5⑽) and A schematic diagram of the corresponding band diagram. Fig. 4A is a telescopic light absorption modulator of the lumped (training) structure of the present invention. Fig. 4B is a travel 丨 structure of the present invention. Calling absorber modulator in Figure 5. Figure 5 Schematic diagram. Table 1. Detailed parameter table of components. [Description of main component symbols] P small η-i_n epitaxial layer 1 P-type doped layer 11 First essential layer 12 First n-type doped layer 13 Second essential layer 14 Second n-type doped layer 15 Semiconductor substrate 2