TW541503B - Capacitive pressure microsensor and methods for manufacturing the same and methods for signal detecting the same - Google Patents

Abstract

There is disclosed a capacitive pressure microsensor for fingerprint verification, its manufacturing methods, and its signal detecting method. The main configuration of this capacitive pressure microsensor is a parallel-plate capacitor which consists of a first e1ectrode plate and a second electrode plate. The first electrode plate is fixed on a substrate at the bottom of the parallel-plate capacitor, and the second electrode plate is at the upside of the parallel-plate capacitor. The structure of the second electrode plate is a suspended plate which consists of at least one pin. The capacitive pressure microsensor further comprises signal-detecting circuits allocated next to each parallel-plate capacitor. The signal-detecting circuit uses a signal-detecting structure of an ameliorated dynamic random access memory (DRAM) to read signals from each parallel-plate capacitor. Each of the parallel-plate capacitor and its signal-detecting circuit are constructed on the same wafer through the integrated circuit manufacturing process. Through a plural number of capacitive pressure microsensors arranged in a matrix form it can detect the changes of the ridges and grooves of a finger to get a fingerprint image which is then used for identification verification.

Description

541503 V. Description of the invention (l), ------ [Background of the invention] Field of the invention The present invention relates to a fingerprint recognition ", to a pressure micro-sensing element, especially a piece, that matches the integrated circuit manufacturing process, And its manufacturing method and digital integration of the digital two-capacity pressure micro-sensing element and the reading processing circuit, and the structure of the 1st acquisition, in order to make the sensing ΛΛ 〇 element into the systematic know-how Describe the conventional fingerprint identification method, which is most embossed on paper and then compared with optical scanning patterns. The biggest disadvantage is none; this cannot meet the increasing number of instant authentication e-commerce, portable electronic product security systems, and so on. The old man uses the finger to press the ink, turns the finger in the computer and the database to achieve the purpose of real-time processing, due to the needs, such as: network authentication, fork 'IC card personal identity authentication, security

Health = Cheng can be used as a sensing system for real-time fingerprint identification. Please refer to U.S. Patent Nos. 4,053, 300. Electronic real-time fingerprint identification systems are under pressure.

2: For the wide contact method, please refer to U.S. Patent No. 4,394,773, Gucong M Ί 40 0, 6 62, 5, 844, 28 7; belong to finger electrostatic induction workers, 'see U.S. Patent No. 4, 42 9 , 41 3. Among them, the optical system is more expensive and consumes high power (light source = high power consumption and large volume (restricted optical component size and arrangement of fixed distance required for optical imaging), making it unsuitable for many portable Electronic products

Page 9 5415〇3 V. Description of the invention (Phantoms such as note-type mines have a great improvement in brain and action, but when they are in contact with the two poles, there will be = making of two electrical materials = and fingers上 了 汗 白 知 技术 所 _ Μ 秦 τ Clothes made in real-time • Small and thin are easy to manufacture. Stability, high power consumption, low price, and other requirements to facilitate its application; personal fingerprints of the mother are different) [Summary of the invention] Therefore, one of the components of the present invention changes the voltage contacting the micro-inductive internal capacitance, and the manufacturing method of the other object of the present invention makes the manufacturing on a single chip greatly reduce the production of telephones and the like. As for electricity, there is still power consumption and large current flow), which does not match the influence of the integrated electrical system (the electrostatic induction fingerprint recognition system is still based on the sub-system's volume (electric contact-based sensing easy and integrated circuit manufacturing process), and Method), making it currently impossible to achieve wide use at the same time as Lijia ’s identity authentication (physical purpose is to provide a measuring element table to quickly advance is to provide a micro-sensing element. This method is not a process, and it can also be ... Method, the purpose of this method is to provide an improved dynamic reading architecture that reads the fingerprint of the fingerprint recognition device, and the capacitance of the hand recognition type can be transparent, but it can easily result in the capacitive pressure micro-sensing of this fingerprint state randomly. The fingerprint circuit can be processed through an integrated circuit through its 0-type pressure micro-sensing element and a fingerprint recognition unit. 0: The signal of the device is read. 2 The signal of the valley-type pressure sensor.

541503 V. Description of the invention (3) The signal of the array, so that each line is not invented. This capacitor next to the capacitor on this substrate is used to read the junction of this parallel plate capacitor to each bit. The electrode plate is located between the second electrode plate and the second electrode plate and is located in the first electrode plate, which is at least connected to the suspension thin film; the force micro-sensing element and the pressure micro-sensing are simultaneously between the top of the plate and the micrometer. The parallel plate on the first electrode electrode plate is a surface element having one connection plate and the other, and is fabricated on the parallel plate structure of at least one of the micro-sensing bit and the capacitor. At least one end of the foot is fixed to include a better measuring element as a capacitor and a less bump. The line parasitic pressure parallel plate capacitor includes a bottom of the electrode central part and is connected to support the base score. The finger-type pressure-height range signal obtains the capacitor's shadow micro-sensing element capacitance, and at least one of the signals between the first electrode plate and the signal transmits the sound correctly. The components include: a base board located at this number, a parallel board circuit. Second electrical air gap to bump. The first is fixed on the substrate; and one of the feet is a floating sheet, and one end of the floating sheet is connected to the board. Sub-protective layer A micro-sensing element should be connected to this capacitive voltage to protect the second electrode of this piece from 2 microns to 10 according to the present invention. The manufacturing method of the pressure micro-sensing element is described in 2. And Congbao road manufacturing process, the value of η is at least greater than the capacitive pressure micro-sensing element: deposition of a η-2 vocal synthesizer is a clothing manufacturing method that includes at least the following steps of interlayer production ... Electric layer; in the η-2 layer intermetal dielectric dielectric etching step, to deposit a tungsten metal film in the second exhibition, and complete the formation of a plurality of metal tethers between the intermetallic dielectric layer

541503 Explanation of the Five Inventions (4) --------- Basic branches; Shen Chuchu Titanium, _ Chedi η — 1 metal layer, this n-1 metal layer system contains one layer ~ layer Minga On η, remove a gold and a layer of titanium nitride; pass the photoresist to the n-1th metal layer of the P knife area at a predetermined position; deposit the n-1th intermetallic layer 'this metal :, layer metal Above the interlayer dielectric layer is deposited on the n-th layer of metal, and the second a layer is a junction metal layer; the n-th layer of metal layer deposited on top of the protective layer through a photoresist is deposited; a protective layer is deposited; • Soil A ′ defines a protective layer etch 4 ® at a predetermined position through the photoresist, and removes Wei and 篦 η 1]] The protective layer and the η-1 intermetal dielectric layer in the quotient are shown in the figure. 1 layer of metal exhibition knowledge and combination of two, 'Zengzhi rat titanium, to expose the η-1 metal layer of aluminum to make at least one, younger one metal layer in the central part, over the protective layer, gold, New Zealand Second-generation bumps; selectively remove aluminum η—Ί titanium metal in the η-1 metal layer to create an air gap with at least φ dielectric layers above it, The n-th metal layer and the protective layer form a dangling / prefabricated plate structure dwelling on the axis of the metal, and spray the cold _ ν Ding plate 1 ^ valley with the η-1 layer of gold square, and , Spray a layer of molecular protective layer on the surface of this element. As described above, according to this & deposition of the η] th metal layer: the use of this / vine 'further includes the following steps: in the η-2th intermetal dielectric layer to a μ reactive ion etching, etch back The plug is at the η-2 layer inter-metal dielectric ==; to expose a plurality of metal plugs at least larger than 0.1 micron. The electrical θ surface, in which the depth of etchback should be in accordance with the present invention, the method for reading signals using dynamic random storage ^ 1 is to take one of the capacitors included in this device; .3 (DRAM) "circuit Structure, read the signal of the electric pressure-type pressure micro-sensing element array, this 541503 V. Description of the invention (5) Memory word lines, one metal oxygen capacity in parallel and one voltage transfer to each method At least the following steps are included: a dynamic random circuit structure is configured, including a group of bit lines and a group of address decoders; the capacitance of the capacitive pressure micro-sensing element array board and each bit line Connect a current source separately; distribute a semiconductor switch (M 0 SS witch) between each parallel plate; and then use this switch to connect the bit line of each parallel plate capacitor. No. reading method) circuit state random access of the circuit element array, each source of a group of character arrays; a Foil ower is configured to use this P-type gold voltage to transfer to the capacitor according to the invention. Invention, but Using another message structure that changes the two heart pattern recognition devices, read this device ^ Mobile sad random access memory (DRAM number, this method ^ less ^^^ including one capacitive pressure micro-sensing memory (DRAM ) = Combine the following steps: · Configure a common moving line 'a set of address solution structure, including a set of bit lines, a parallel plate capacitor and service f; this capacitive pressure micro-sensing P-type metal oxide semiconductor ~ The bit line is connected with a current) to each parallel plate, and the source follower (PMOS Source is an oxide semiconductor source) and each bit line; and the bit green connected to it With the light device, the interference of each parallel plate capacitor is avoided. After the 'to avoid each bit line's description of the drawings of the present invention, the characteristics and advantages of the face can be more clearly understood by referring to the following and: % Of the preferred embodiment

Page 13 541503 V. The description of the invention (6) H1 n The fingerprint identification device part of the embodiment of the present invention ^; I i ^ :: micro "pitch 10 of the component 10. Each J pressure is micro. The structure of the element is mainly a parallel plate capacitor 20, including the ^ pole at the bottom; te Γ diagram Φ soil-, ua · low # 's di-electrical inversion (α 中 未 不) and the second electrode above Board; and the 2: 2 one suspension board 4 board structure 201, supported by two connecting feet 202; the connecting foot = = immortal and overhang and the first-Lei II: (not shown in the figure) 'formed in The first-adjacent 811: in the middle of the board; a bump 203 'is located in the center of the suspended sheet 201: ,,, a; V knife protective layer covering the entire surface of the entire component (picture; no), at each pressure In the micro-sensing element 10, corresponding to each of the flat rods, the signal obtaining circuit 30 of FIG. 2 is made of ^ / 〇 at 2 p / kg, which is not a parallel plate capacitor 2 〇 and its signal reading circuit t ^ 5 ^ 09 ^ 51 ^ ° w Private road 5 0 9 and 510 respectively represent a character line used to read the signal. The signal reading method of this pressure micro-sensing element will be described later, please refer to Figure 3, my The fingerprint identification principle shown in Figure 丨 will be explained in detail. Figure 3 shows a cross-sectional view of the capacitive sensing element array of Figure i when it is in contact with a finger. The electrode plate 41G and the second electric plate 42 °, and an air gap of 400 ° is formed between the two electrode plates. When a finger 70 contacts the pressure micro-sensing element array, only a part of it is sensed. Page 14 541503

The measuring element is in contact with the fingerprint bump 40 (some of the sensing elements are covered by the fingerprint recess 50, 60 times), and the pressure from the finger is felt. This pressure causes the floating plate of the measuring element to generate a displacement. d (the amount of displacement depends on the pressure = pressure), and then change the capacitance value between the two parallel plates, through the circuit 4 T 'can be reflected in this array, the fingerprint bumps 40 contact with the change The pressure micro-sensing element 丨 0, and then the shape distribution of the fingerprint bump 40 is constructed. The conventional fingerprint recognition is to judge the shape distribution of the fingerprint bumps on the plane ', and the distance between any two fingerprint bumps is about 2000 ~ 800 microns, so the distance γ of the pressure micro-sensing element must be smaller than the fingerprint protrusion The spacing of the points. At the same time, the area of the main part of the fingerprint identification is about cra x cnl, so if Y is equal to 80 micrometers, then 1 2 8 X 1 2 8 sensing elements must be made to meet the requirements. Please refer to FIGS. 4A to 4C, which are manufacturing process diagrams of the pressure micro-sensing element array shown in FIG. 1 along the line B-B of FIG. For the sake of simplicity, only the parallel plate capacitance 20 of a single pressure micro-sensing element 丨 0 is drawn in this figure to illustrate the main structure of the pressure micro-sensing element 丨 0 and the manufacturing method thereof.

(1) As shown in FIG. 4A, it is a process using a commercial sub-micron, n-layer metal stone integrated circuit (especially a complementary metal-oxide-semiconductor half-CMOS process, and the value of η is at least greater than 2). The finished pressure micro-sensing element 10 semi-finished products. Since the integrated circuit manufacturing process is a well-known technology, the detailed process description will not be repeated here, and only the structure and material properties of the parallel plate capacitor pressure as the sensing element will be described as follows: First, a η-2 layer intermetallic layer is deposited Dielectric layer 30; on the second layer

Page 15 541503 V. Description of the invention (8) Interlayer dielectric layers 3 and 3 are used to make a plurality of dielectric layer perforations; a crane metal film is deposited and an etch-back step is completed to interpose the n-2th intermetallic layer A plurality of metal plugs 310 are formed between the electrical layers; an η-1 metal layer 3 04 is deposited on the surface. The structure of this metal layer is usually titanium 304a / aluminum alloy 304b / nitride (in the figure) (Not shown) sandwich structure, in which the n-1th metal layer 304 passes through the plurality of metal tethered pillars 310 and the conductors below the n-2th intermetal dielectric layer 303 The connection layer (not shown) (a metal layer or a polycrystalline silicon layer) is connected. The lithography and etching techniques are used to remove the n-I-th metal layer 304 in a part of the area so as to leave the n-th} metal layer ⑽ of a predetermined area. Then, an n-i layer intermetal dielectric layer 305 is covered on the entire surface. After that, an n-th acoustic metal is deposited on the η_1-layer intermetal dielectric layer 305, and the 0th metal layer 306 is a metal layer. Use of lithography and money === Dividing the 11th metal layer 306 of a part of the area; forming a layer on the entire surface 30 ΓΛϋ 'Photographic and engraving techniques simultaneously remove part of the protective layer 304 ^ ^ η intergeneric dielectric Layer 305 and a portion of the η-1 layer metal, η7 titanium oxide, to expose the etching window σ 30h of the aluminum alloy metal layer 304b. Then in the protective layer 3007 = to the solid mouth as a raised bump 3 08. ^, First resistance or metal material metric to 1. Between micrometers. -The preferred height range of the bump 308 is formed by 2 microi £ alloy metal layer / oib, the t-cut window 307 & under the predefined aluminum temperature can be supplied, Φ vinegar rolling a, at an appropriate Proportioning and removal of material (> 1 micron / min). Simultaneously,

Page 16 541503 V. Description of the invention (9) It has excellent selectivity for titanium 304a, so it can complete the selective etching technique for removing aluminum 304b and leaving titanium 304 ^. Titanium 304a is the first metal layer of the parallel plate capacitor, and it forms the first electrode of the parallel plate capacitor 20 with the n-2th intermetal dielectric layer 30 and the plurality of metal plugs 3 10. Board 41〇. The ηth metal layer is the second metal layer of the parallel plate capacitor 20, and the n-j ^ intermetal dielectric layer 305 and the protective layer 307 will constitute the second electrode of the parallel plate capacitor 20. After the second electrode plate 420 is etched by aluminum, it will become a suspended thin plate structure supported by two connecting legs 202. (2) As shown in FIG. 4C, in order to further protect the pressure micro-sensing element, for example, to prevent dust, a polymer protective layer 3 09 is formed on the outermost surface of the element by spraying and spinning, such as polyvinylamine. (P〇 丨 y 丨 mi de) to form a pressure micro-sensing element with a closed cavity. From the above description, I should note that the manufacturing process of Figure 4A to Figure 4B and all the materials and manufacturing methods selected are fully compatible with today's various commercial integrated circuit manufacturing processes, and the manufacturing process of Figure 4C However, it is not necessary to require any photomask manufacturing process to simplify the manufacturing process. This is the most important spirit of the present invention. A fabless production method is established (only a simple micro-electromechanical back-end process is required), similar to IC design. The company's philosophy is to greatly reduce costs and increase competitiveness. At the same time, the integrated manufacturing process makes it easier to integrate the reading and processing circuits on the same chip to complete the systematic chip manufacturing. FIG. 5 is a schematic diagram of a process improvement of another embodiment of the present invention. The manufacturing process of the structure shown in FIG. 5 is almost the same as that of the drawings “to 4 (:, its production is not described here. The difference is only the deposition of the n_ 丨 layer in the aforementioned process

Page 541 503

Multi-step before the metal layer 304: using reactive ion rhenium, contact the first intermetal dielectric layer 303 to a depth, so that a plurality of metal plugs 枉 3 ^ 0 protrude from the n_2 intermetal dielectric layer 3 〇3 surface, wherein the degree of etchback should be at least greater than 0.1 microns. This will help prevent the suspended thin plate 201 and the first electrode plate 410 at the bottom from being adsorbed together due to the liquid surface tension during the subsequent formation of the air gap 4. * The above is the structure and manufacturing method of the capacitive pressure micro-sensing element of the present invention. We will make a detailed description of the signal reading method of the capacitive element of the present invention below. To

/ In the present invention, the fingerprint recognition device is composed of an array in which a plurality of capacitive pressures are arranged by the sensing elements. This structure is compatible with the conventional arrangement of storage capacitors in the Ik memory access device (7). Therefore, the storage pen in the random access memory device (dram) is used for 5 pounds each. The circuit can be applied to the present invention, which is one of the features of the present invention. The digital readout architecture through dram (all fingers and text recognition devices in the conventional technology are analog readout architectures), which can be eliminated. Analog / digital conversion in hardware, and binary processing in identification software. First of all, let me make a simple statement about the memory reading architecture that I use.

Eye tea is shown in Figure 6, which shows the traditional memory reading architecture, which includes storage capacitor array 5 0 0, data read and write control 5 0 1, timer 50 2, line pre-decoder 503, lockout prevention 504, Column Decoder 505, Row Decoder 506, Read Amplifier 508, and Reference Element to Improve Sensitivity

Page 18 541503

5. Description of the invention (π) 507 (dummy cel 1), the read sensitivity of the entire DR AM is limited by the Jiancun 6 array 500, the reference element 507, and the read amplifier 508. Figure 7 shows a detailed structure diagram of the capacitive pressure micro-sensing element array of the present invention. In order to avoid dry selection between adjacent sensing elements, a set of parity word lines 50 9a , 50 9b, to make each of them alternately open the chip to set the address. The method of reading the signal from a fingerprint recognition device is to use the circuit structure of dynamic random access memory (DRAM) to read. The signal of this capacitive pressure micro-sensing element array is included in this setup. The method includes the following steps: configuring a circuit structure of a conventional dynamic random access memory (⑽ ^), including a set of bit lines , A set of word lines, a set of soil decoders; and each parallel plate address valley and the female bit line of this capacitive pressure micro-sensing element array are connected to a current source respectively; and configuration_metal = A semiconductor switch (MOS Switch) is placed between each parallel plate capacitor and each oxygen line; this switch is then used to pass the voltage of each parallel plate capacitor to the bit line to which it is connected. Since the bit line 5 1 0 (bit-1 ine) itself will form Capacitors are generated, so the longer the bit line 5 1 0 and the more sensing elements, the larger this parasitic capacitance, which greatly reduces the voltage signal read by the sensing element to the bit line. Therefore, the present invention In view of this problem, another modified signal reading method of ^ ^ will also be proposed. Please refer to FIG. 8 and FIG. 9 for the formula. FIG. 8 shows another improved signal reading architecture of the fingerprint identification device of the present invention. Figure 9 shows the relationship between input voltage and time for this improved signal reading architecture. This new architecture is used

Page 19 541503 Description of the invention The parasitic capacitance of the solution line 510 and the capacitive pressure micro-sensing element "is too large, so that the capacitive pressure micro-sensing element reads to the bit line 51 0 The voltage signal is greatly reduced. The new architecture connects each bit line BL 51〇 and the parallel plate capacitor 20 of each capacitive pressure micro-sensing element 10 to a current source and a p-type metal gasification semiconductor, respectively. Source follower (PM〇s〇urce F〇u〇wer) 5 ι, so that the voltage on the first electrode plate 4 of the parallel plate power valley is correctly transferred to the bit line without being affected by the bit line parasitic capacitance Impact.

As shown in Figure 8 and Figure 9, * This capacitor two micro-sensing element is in a state of non-reading. The input voltage on word line 509 and pulse word line 512 (pulse w 0rd 1 ine) will be Is ov, so that the p-type metal oxide semiconductor (PM0S) 513 connected to the parallel plate capacitor 20 will be maintained in an open state, because the contact 514 of the first electrode plate and the silicon substrate 2000 are simultaneously connected to Vdd, There is no potential difference between the two ends of the capacitor 205 between the two, so it is not charged, and only the capacitor 204 between one electrode plate and the second electrode plate of the parallel plate electric f20 is charged; and in the reading state, the word line 50 9 And pulse character line 512 (pulse w〇rd

(ilne) input voltage will be 5V, make PM0S 513 turn off, cut off the Vdd current source of the first electrode plate, and also make the inverter 5 2 0 switch from high potential to low potential, then the silicon substrate 2 0 0 is grounded In the state, the second electrode plate 420 of the parallel plate capacitor connected to the ground is connected. Therefore, the electric charges of the capacitors 204 and 50 will be redistributed between the first electrode plate and the silicon substrate, and then the voltage will be transferred to the p-type metal oxide semiconductor source through the contact 514 of the first electrode plate. Follower 511 (PMOS Source Follower), because of this pM〇ss〇urce

Follower's magnification is close! , P within 5ΐι of this source follower

541503

Type metal oxide semiconductor 5 1 6 # 6R, π &] is very many, and the voltage between the point 5 1 7 and the source extreme point 5 1 8 is close to two kilograms, by measuring the bit line BL 51〇 Through the terminal 51: the voltage change to the source P side coupler 511, the voltage value of the terminal 51, that is, the first electrode plate can be obtained. Anyway, ^ ^ ^ 疋 Therefore, the signal of this capacitive micro-sensing element can be correctly transmitted to the bit line BL 5 i 〇 without being affected by its parasitic capacitance. Figure 9 is a diagram of the relationship between the input voltage and time for this improved signal reading architecture. The reading or non-reading state of the electric valley M sensing element is composed of the word line 5 0 9 and the pulse word line 5 1 The input voltage control on 2 measures the voltage value of the terminal 5 i 8 to obtain the voltage value of the first electrode plate represented by the terminal 5 1 7. When the electric valley-type sensed element is in a non-reading state, that is, the capacitor 204 between the first electrode plate and the second electrode plate is charged, the word line 509 and the pulse word line 512 The input voltage will be 0v, and the voltage value at the terminal 51? Is the same as the contact 5 1 4 of the first electrode plate as Vdd; before switching from the non-reading state to the reading state, the pulse word line 512 must switch the input voltage to 5V, so that pm0s 513 transmits a stable signal to the first electrode plate contact 5 1 4 to cut off Vdd early, and then switch the input voltage on the word line 509 to 5V; in the reading state, the capacitance 2 04 reads There are two modes of the output signal: (1) the fingerprint bump makes the capacitor 2 04 be pressed,

Cmp is the maximum value, then the voltage of the first electrode plate at the terminal 5 1 7 is the maximum value; (2) When the fingerprint pits make the capacitor 204 not under pressure, Cmp is the minimum value, then the first electrode plate at the end 517 The voltage value is a minimum; the dummy voltage value is its average. The voltage change of the terminal 5 1 8 measured in the reading state is consistent with the voltage change of the terminal 5 1 7. By comparing the voltage changes of each capacitive pressure micro-sensing element constituting this fingerprint identification device, a fingerprint image can be obtained

P.21 541503 V. Description of the invention (14). The specific embodiments proposed in the detailed description of the preferred embodiments are only used to facilitate the description of the technical content of the present invention, rather than limiting the present invention to the above embodiments in a narrow sense, without exceeding the spirit of the present invention and the following In the case of applying for a patent, the various changes made are still within the scope of the present invention.

Page 541503 Brief Description of Drawings Figure 1 is a three-dimensional structure diagram of a capacitive pressure micro-sensing element array according to an embodiment of the present invention; Figure 2 is a parallel plate capacitor inside a capacitive pressure micro-sensing element according to one of the present invention And signal reading circuit configuration diagram; Figure 3 is a sectional view of the capacitive pressure micro-sensing element array of FIG. 1 in contact with a finger; FIGS. 4A to 4C are along the capacitive pressure micro-sensing element array shown in FIG. FIG. 1 is a manufacturing process diagram of a line BB; FIG. 5 is a schematic diagram of an improved manufacturing process of a capacitive pressure micro-sensing element according to another embodiment of the present invention; FIG. 6 is a reading architecture diagram of a conventional dynamic random access memory Figure 7 is a detailed architecture diagram of the capacitive pressure micro-sensing element array of the present invention; Figure 8 is an improved signal reading architecture diagram of the fingerprint identification device of the present invention. FIG. 9 is a relationship diagram between input voltage and time of an improved signal reading architecture of a fingerprint identification device of the present invention. Explanation of symbols 10 Capacitive pressure micro-sensing element 20 Parallel plate capacitor 2 0 0 Silicon substrate 201 Floating sheet

Page 23 541503

The drawing briefly explains 202 the connecting pin of the floating sheet 202a the 2nd 0 2b of the connecting leg of the floating sheet 203 the bump 204 the first electrode of the parallel plate capacitor 205 the first electrode of the parallel plate capacitor 30 signal reading Take circuit 303 n-2 intermetal dielectric layer 304 n-1 metal layer 3 04a titanium 3 04b alloy metal layer 305 n-1 intermetal dielectric layer 306 n metal layer 307 protective layer 307a Etching window 308 Bump 310 Embed metal 310a Metal bump 40 Fingerprint bump 400 Gap 410 First electrode plate 420 Second electrode plate 50 Fingerprint pit 500 Storage capacitor array page 24 541503 Illustration of simple illustration 501 Data read-write control 5 0 2 Timer 503 Row Pre-Decoder 504 Blocking Prevention 5 0 5 Column Decoder 50 6 Row Decoder 5 0 7 Reference Element 5 0 8 Read Amplifier 5 0 9 Word Line 5 0 9 & Odd Line 5 0 9b Even word line 510 bit line? 511 P-type metal oxide semiconductor source follower 512 Pulse word line 513 P-type metal oxide semiconductor connected to parallel plate capacitor 514 Contact 515 of the first electrode plate Electrode plate contact 516 P-type metal oxide semiconductor source follower P-type metal oxide semiconductor 517 P-type metal oxide semiconductor gate extreme point of source follower 518 P-type metal oxide semiconductor source follower Source extreme point 519 N-type metal oxide semiconductor transistor of source follower 52 0 Inverter 60 Fingerprint pit

Page 541 503

Schematic description of 70 BL Cmp Cpb RIE PWL Vdd WL Finger bit line Parallel plate capacitor Capacitance between the first electrode plate and the second electrode plate Capacitance reaction between the polycrystalline silicon layer of the parallel plate capacitor and the silicon substrate Ion etching pulse character Line current source character line

Page 26

Claims (1)

541503 VI. Application for patent scope 1. A capacitive pressure micro-sensing element for fingerprint identification includes: a base, a flat plate, and a line capacitor, which is manufactured above the substrate and used to sense the applied surface of the uneven surface of the fingerprint. The structure of the parallel plate capacitor includes at least: a first electrode plate, which is located at the bottom of the parallel plate capacitor and is fixed on the substrate; a second electrical line has at least one connecting leg for supporting the one end; It is fixed in the air space; and at least one convex one signal reads and outputs the parallel plate. A polymer is used as a finger to contact the electrode plate, which is located above the parallel plate capacitor and is a suspended thin plate with feet. Among them, the At least one connected suspension plate, one end of which is connected to the suspension plate, and on the other substrate; a gap is located in a block between the first electrode plate and the second electrode plate, and is located in a central portion above the second electrode plate; Is located next to the parallel plate capacitor to read the signal transmitted by the capacitor; and a protective layer is used to protect the pressure micro-sensing element, and faces 0 2. The patentable scope of application of the first item capacitive pressure differential sensing element 1, wherein, the first electrode plate comprises at least a first metal layer, the second electrode plate includes at least a second metal layer. 3. For the capacitive pressure micro-sensing element according to item 2 of the patent application scope, wherein the first electrode plate further includes 541503 6. Scope of patent application: a first intermetallic dielectric layer is interposed between the substrate and the first metal layer; and a plurality of metal plugs are fabricated between the first intermetallic dielectric layer; And the second electrode plate further includes a second intermetal dielectric layer located under the second metal layer; and a protective layer located above the second metal layer. · For example, the pressure micro-sensing element for fingerprint identification according to item 3 of the patent application scope, wherein the plurality of metal plugs are protruded from the surface of the first intermetal dielectric layer and are used for the first metal. A plurality of metal bumps are formed between the inter-dielectric layer and the first metal layer. 5. For the capacitive pressure micro-sensing element according to item 1, 2, 3, or 4, in which the preferred height range of the at least one bump above the second electrode plate is between 2 micrometers and 10 micrometers. between. 6. A method for manufacturing a capacitive pressure micro-sensing element, which is a one-time micron η-layer aluminum metal integrated circuit manufacturing process, which includes at least the following steps: depositing a η-2 layer intermetal dielectric layer; A plurality of dielectric layer penetrators L are made between the η-2 intermetal dielectric layers; Page 28 541503 6. Apply for a patent to deposit a tungsten metal film and complete the etch-back step to form a plurality of metal plugs between the η-2 intermetal dielectric layer; deposit the η-1 metal layer, The η-1 metal layer includes a layer of metal, a layer of alloy, and a layer of titanium nitride; a part of the area of the η-1 metal layer is removed through a photoresist at a predetermined position; and a layer of η-1 is deposited An intermetal dielectric layer is deposited on top of the η-1 intermetal dielectric layer, and an η metal layer is deposited. The metal layer is a metal layer; a part of the area is removed through a photoresist at a predetermined position The n-th metal layer; depositing a protective layer; defining a protective layer etching window at a predetermined position through the photoresist above the protective layer; removing the protective layer and the η-1 from the etching window Intermetal dielectric layer and titanium nitride of the η-1 metal layer to expose the aluminum alloy surface of the η-1 metal layer; in the central part of the η-1 metal layer, the Above the protective layer, at least one bump is made; and the n-th is selectively removed. The aluminum alloy in 1 metal layer, leaving the titanium metal at the bottom to create an air gap, so that the η-1 intermetal dielectric layer, the η metal layer and the A protective layer, forming a suspended thin plate structure supported by at least one connecting leg, and forming a parallel plate capacitor with the titanium metal of the η-1th metal layer; and Page 29 541503 6. Scope of patent application Spraying a polymer protective layer on the surface of this component. 7. The manufacturing method of the capacitive pressure micro-sensing element according to item 6 of the patent application, wherein the method further includes the following steps: before depositing the η-1 metal layer, using reactive ion etching to etch back The n-2th intermetallic dielectric layer has a depth to expose a plurality of metal plugs. 8. If the method of manufacturing a capacitive pressure micro-sensing element according to item 6 or 7 of the patent application scope, wherein the value of η is at least greater than two. 9. The method for manufacturing a capacitive pressure micro-sensing element according to item 6 or 7 of the patent application, wherein the bump is a photoresist or a metal material. 10. The manufacturing method of the capacitive pressure micro-sensing element according to item 6 or 7 of the patent application scope, wherein the selective etching solution for removing the aluminum alloy is a mixed acid solution of phosphoric acid, nitric acid and acetic acid. 11. The manufacturing method of the capacitive pressure micro-sensing element according to item 6 or 7 of the patent application scope, wherein the material of the polymer protective layer is polyvinylamine. 12. The method for manufacturing a capacitive pressure micro-sensing element according to item 7 of the scope of patent application, wherein the η-2 layer is etched back by reactive ion etching Page 30 541503 VI. The scope of the patent application The intermetallic dielectric layer has a Λ / clothing degree of at least greater than 0.1 micron 13. A conventional method of using a mobile device to package 'encapsulates each and every flat electricity 14.- Conventional The method of the moving device is composed of each bit method. This method uses a circuit structure including a dram body (dRam) to read the signal of one of the capacitive pressure micro-sensing element arrays = 3, this ^ ^ White use dynamic random access memory (DRAM) circuit structure: the: ΐ: 3 :: group word line,-. Group address decoder; line two = f force micro-sensing element array each parallel The plate capacitor and the π line are respectively connected to a current source; the ^ ρ-type metal oxide semiconductor switch ㈧ 仃 between the plate capacitor and each bit line; ch) reuse the p-type order _ ^, 压 传 # $ A 1 π _ belongs to a semiconductor switch that transfers each parallel plate & to the bit line to which it is connected. A fingerprint identification device > 4 π Μ can be placed in alum, which is a method to read the circuit structure of rn D Λ Μ \ 48 U basket (DRAM) The = contains-the signal configuration of the capacitive pressure micro-sensing * customary dynamics with the German Renyi's memory access memory (DRAM) circuit grouping character lines,-group address decoder; will: Each parallel-plate capacitor and 70 wires of the pressure micro-sensing element array are respectively connected to a current source; a P-type metal oxide semiconductor source follower (PM0S 541503 VI. Patent application scope Source Follower) between each parallel plate capacitor and each bit line; and then use the P-type metal oxide semiconductor source follower to transfer the voltage of each parallel plate capacitor to its connection Bit lines to avoid the interference of parasitic capacitance of each bit line. Page 32