TW201248987A - Bandpass filter using thin film microstrip line - Google Patents

Abstract

The present invention discloses a filter using thin film microstrip line, comprising a semiconductor substrate, an oxidation layer, a metal layer, a dielectric layer and at least four ground electrode pads. The filter according to the invention is used the low-k dielectric material for a substrate. The filter can apply on the design of filtering device in millimeter wave devices.

Description

201248987 VI. Description of the Invention: [Technical Field] [0001] The present invention relates to a filter, and more particularly to a microstrip line bandpass filter fabricated on a low dielectric constant film. [Prior Art] [0002] In recent years, integration of deep submicron BiCMOS active components with passive components in a monolithic microwave integrated circuit (MMIC) has been considered to be toward high performance and low efficiency. The best solution for cost 1C technology is also the ultimate goal of achieving system-on-chip (S0C). In order to integrate a large number of passive components and reduce the crosstalk effect between components; especially the distributed impedance matching network and transmission line between active and passive components. Substrate loss and Average power handling capability (APHC) must be carefully evaluated. [0003] Active components of a radio frequency integrated circuit (RFIC) are fabricated on a substrate having semi-conductivity, such as standard twinning and gallium arsenide (GaAs). Twine is the first choice. However, standard twins have significant losses in the RF band with extremely low APHC. Therefore, there are currently about four solutions to solve the problem of loss of standard twins in the RF band: (1) The passive components are fabricated on a thick dielectric layer (>50 μηι) to keep the components away from standard twins to reduce losses; (2) Use high resistivUy silicQn (HRS) to reduce the carrier's ability to pass between the transmission line and the substrate, and to improve the resistance between the transmission line and the substrate. (3) Use a proton cloth above MeV. Plant Technology 'converts (10) to delete; and (4) uses MEMS (Micro 1002031199-0 100118523 Form No. A0101 Page 3 of 14 201248987 electro mechanical systems, MEMS) process technology to remove the back side of the substrate or deep button Below the conductor line, to reduce the RF loss of the standard Shi Xijing. The main disadvantage of HRS is that it requires high-energy implant technology, which is not compatible with the standard CM〇s process, which will increase the manufacturing cost and component performance instability; MEMS technology has mechanical stress and high complexity. The disadvantages of the process and low operating life. [0004] [0006].

[0007] 100118523 In MMIC, low dielectric constant (l〇w dielectric constant,

Low-k) materials are commonly used as dielectric and interconnect components for logic gate components. This is because Low-k materials have the advantages of high propagation margin, low loss, high insulation and high thermal conductivity. Similarly, in the packaging of RF and microwave components, if the passive component is to be integrated with the active component, the passive component must be fabricated on a highly insulating film. Polyimide is widely used. One of the L〇w_k materials. Therefore, in order to achieve the goal of the system-level wafer and solve the above problems, it is necessary to provide a thin-film microstrip line pass-through waver to overcome the disadvantages of the prior art. SUMMARY OF THE INVENTION The main object of the present invention is to provide a thin-band wire material. The filter is a microstrip line bandpass filter fabricated on a low dielectric constant film. Used in single stone microwave integrated circuits (MMIC). To achieve the above main object, the present invention provides a thin film microstrip line filter device comprising a semiconductor substrate, an oxide layer, a metal layer, a dielectric layer, and at least four ground electrodes and a cell. The oxygen layer has a thickness of about 2 nm to about 〇 nm and is deposited on the semiconductor substrate.

The degree is about G.5 _(4) and is deposited on the oxide layer J. A No. A0101 Page 4 of 14 201248987. The dielectric layer has a thickness of about 15 /zm to 20 #ηι and is deposited on the metal layer. The ground electrode is defined by a semiconductor process and deposited on the dielectric layer and electrically connected to the metal layer. The filter unit has a first signal input port and a second signal input port, and is defined by a semiconductor process and deposited on the dielectric layer. Wherein, the metal layer serves as a ground plane of the thin strip line pass filter of the thin film. The dielectric layer acts as a carrier body for the thin film microstrip line pass filter. The first signal output port and the second signal input port and the ground electrode are disposed on the dielectric layer in a coplanar waveguide structure. A feature of a thin film microstrip line bandpass filter according to the present invention, wherein the semiconductor substrate is a germanium semiconductor. A feature of a thin film microstrip line bandpass filter according to the present invention, wherein the metal layer is aluminum. A feature of a thin film microstrip line bandpass filter according to the present invention, wherein the dielectric layer is a low dielectric constant material having a dielectric constant of between about 1.5 and about 3. [0011] A feature of a thin film microstrip line bandpass filter according to the present invention, wherein the filter unit is comprised of a plurality of one-half wavelength coupled line resonators. The above and other objects, features, and advantages of the present invention will become more apparent from the description of the appended claims. [Embodiment] [0013] Although the present invention can be embodied in different forms of embodiments, the figures shown in the drawings are 100118523, form number Α 0101, page 5 / page 14 1002031199-0 201248987; The preferred embodiment is to be understood as being limited to the illustrated embodiment and/or described in the specific embodiments. [0015] The object of the present invention is to achieve low cost, high integration and the ultimate goal of fully integrating active and passive components. Therefore, in the MMIC wave-wave component, the Thin Film Mierostrip Line (TFML) is The best solution; especially in the V-band (V-band, 50~75 GHz) or more 'thin microstrip line structure is one of the best candidates for RF system-level chips. It has the following advantages: (1) about 2 〇μιη thick p〇lyimide is quite easy in the remaining and melamine process, and also conforms to the standard CMOS process, (2) TFML has a relatively small size, which can greatly improve the off 1 ( : The component accumulation degree, (3) The ground plane of TFML isolates p〇iyimide from the fragmentation crystal, which can effectively reduce the noise and substrate crosstalk (Cr〇sstalk) effect during component operation. (4) Polyimide is low dielectric The coefficient and the high insulating material' can effectively reduce the dispersion 1 (: dispersion ef -fects of the inner connecting element ° Please refer to Fig. 1 and with Fig. 2, which shows the thin film microstrip line pass filtering Side view and top view of the device 100. The thin film microstrip line pass filter 100 comprises a semiconductor substrate 11 (), an oxide layer 2, a germanium metal layer 130, a dielectric layer 140, at least four The ground electrode 150 is connected to the filter unit 160. The semiconductor substrate 11 is a germanium semiconductor. The oxide layer 12 is a double emulsion film having a thickness of about 2 nm to 10 nmii deposited on the semiconductor substrate 110 using a Tibetan bond. The upper layer of the metal layer 130 is used to have a thickness of about 0.5 //m~2 And deposited on the oxide layer 12〇. The dielectric layer 140 is a low dielectric constant material having a dielectric constant of about 1. 5 ~ 100118523 Form No. A0101 Page 6 of 14 1002031199-0 201248987

The thickness is about 15 centimeters to 20 Am and is deposited on the metal layer. The ground electrode 15G is defined by a semiconductor process and washed: the electrical layer (4) is electrically connected to the metal. The money unit is composed of a plurality of one-wavelength light-receiving line resonators 163, and has a first signal wheel in and out of the 埠m and a second signal output 埠' according to the wave H unit 16 〇 The process is defined and deposited on this layer 14〇. In the middle of the installation, the ground plane of the _^ human wave device is used as the microstrip line of the film. The "Electrical Layer" 140 serves as a carrier body of the thin film microstrip line filter 1 . The first signal output port 6 and the second mirror output port 162 and the ground electrode 150 are arranged on the dielectric layer 14A in a coplanar waveguide. . [0016] The benefit of using the ruthenium substrate 110 is unquestionable in designing the silk material. However, when implementing the RF passive tree substrate, it is difficult to achieve the serious loss due to the low insulation of the substrate mountain. The RF passive component needs to be deposited on the substrate 11G to a thickness of about 2 (). The dielectric constant material film is formed by a metal layer 13 〇 as a ground plane for isolating the dielectric layer 140 from the XI XI substrate 11 〇. The presence of the metal layer 13〇 prevents the electromagnetic force lines in the dielectric layer 140 from being affected by the electrical characteristics of the stone substrate to produce an associated dielectric loss effect. [0017] In the process, the thickness of the oxide layer 120 is a dioxide thin film, which uses a reduced ship deposition (four) semiconductor substrate UQ on a metal layer 13 〇, using aluminum, which is deposited by sputtering The oxide layer 12 has a thickness of about 2 μm. The dielectric layer 14 is made of a low dielectric material, P〇lyimide ur - 2.2 at, which is deposited on the metal layer 130 by swaging. The grounding electrode 15 () money _ forging 100118523 table Α Α 0101 7 1 / a total of U 1 1002031199-0 201248987 deposited on the dielectric layer 丨 4 并 and with inductively coupled plasma (IndUctively coupled Plasma, Icp The etching method defines the position of the ground electrode 150. Referring to FIG. 3, there is shown a structural diagram of a filter unit of a thin film microstrip line band pass filter, which is a preferred embodiment of the present invention. The filter unit 160 is a parallel coupled line filter structure with a center of 0 2 GHz, a chopping of 〇. 5 dB, a bandwidth percentage of BWR = 〇.丨, and the attenuation should be less than 20 at a frequency of 21. 65 GHz. dB. Therefore, by

The D equation can be used to determine the frequency response of the low-pass prototype filter to the frequency response of the bandpass filter:

ω ( \ a 1 ( =− 0.1\ 1.65 2 :10 X—0.387 = —3.87 (1)

1=2,87 ’After looking up the table, it is known that the series Ν > 2 will have an attenuation of more than 20 dB. Therefore, the chopper low-pass filter prototype with a Chebyshev 0.5 dB equal to the number of stages N = 2 is selected. The component values of the prototype low-pass circuit are obtained by looking up g0 = l, gl = 1.4209, g2 = 0.7071 and g3 = 〇 1. 9841. The characteristic impedance of the 'first signal output port 161' and the second signal output port 162 is selected to be 50 Ω. Further to find out the value of each admittance converter:

A 70 J2-FO J3-FO

ΙπΒΨΚ ] nBWR 0.33249 UBWR 1 2^3 0.15671 0.33461 The odd and even modal characteristic impedance of the coupled line can be 100118523 Form No. A0101 Page 8 of 14 1002031199-0 201248987 N = 1 Ζ〇Λ = z0[l + JNxZ0 + (JN X Z0)2] = 38.9 = Z0[l - JN x Z0 + x Z0)2] = 72.2 N = 2 = z0[l + JN X z0 + X z0)2] = 43.3 z〇, = ^ 〇[l - Λ x Z0 + (JN x Z0)2] = 59.1 N = 3 〇Z0〇= [1 + ^ X z0 + X z0)2] = 38.9 Z〇e = AP - *4 x ^ + ( A x 4)2 ] = 72.3 After the odd and even mode characteristic impedances of the coupled line are calculated, the size of each pair of half-wavelength coupled line resonators 163 can be determined, and then filtered by the full-wave electromagnetic simulation software. Characteristic analysis of the device. In summary, the present invention discloses a thin film microstrip line bandpass filter 1A including a semiconductor substrate 110, an oxide layer 12, a metal layer 13, and a dielectric layer 140. At least four ground electrodes 150 and a filter unit 160. The thin film microstrip line bandpass filter 1 uses a low dielectric constant dielectric layer 140 as a carrier body, and is suitable for operation in a centimeter wave filter element. The present invention has been disclosed in the foregoing preferred embodiments, and is not intended to limit the scope of the invention, and various modifications and changes may be made without departing from the spirit and scope of the invention. As explained above, all types of corrections and changes can be made without destroying the essence of the invention. 100118523 Form No. A0101 Page 9 of 14 1002031199-0 201248987 God. Therefore, the scope of the invention is defined by the scope of the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS [0022] Fig. 1 is a side view showing a thin film microstrip line band pass filter. Figure 2 shows a top view of the thin film microstrip linepass filter. Figure 3 shows the structure of a filter unit for a thin-film microstrip linepass filter. [Major component symbol description] 100 thin film microstrip line band pass filter 110 semiconductor substrate 120 oxide layer 130 metal layer 140 dielectric layer 15 0 ground electrode 160 filter unit 161 first signal input and output 埠 162 second signal output 埠〇163 Half-wavelength coupled line resonator 100118523 Form No. A0101 Page 10/Total 14 Page 1002031199-0

Claims (1)

201248987 VII. Patent application scope: 1. A thin film microstrip line band pass filter, comprising: a semiconductor substrate; an oxide layer deposited on the semiconductor substrate, the thickness of which is between about 2 nm and 10 nm; a metal layer deposited on the oxide layer having a thickness of about 0.5 /zm~2 as a ground plane of the thin strip line pass filter of the thin film; a dielectric layer deposited on the metal layer a thickness of about 15 /zm~20 /zm, as the carrier body of the thin-film microstrip line bandpass filter; 〇 at least four ground electrodes, defined by a semiconductor process and deposited on the dielectric layer Electrically connected to the metal layer; and a filter unit having a first signal input port and a second signal input port, defined by a semiconductor process and deposited on the dielectric layer; wherein A signal output port and the second signal input port and the ground electrodes are disposed on the dielectric layer in a coplanar waveguide structure. 2. The thin film microstrip line band pass filter of claim 1, wherein the semiconductor substrate is a dream semiconductor. The thin film microstrip line band pass filter of claim 1, wherein the oxide layer is a ceria film and is deposited on the semiconductor substrate by sputtering. 4. The thin film microstrip line bandpass filter of claim 1, wherein the metal layer is one of a group consisting of aluminum, platinum and gold. 5. The thin film microstrip line band pass filter of claim 4, wherein the metal layer is aluminum. 6. The thin film microstrip line bandpass filter of claim 1, wherein the dielectric layer is a low dielectric constant material, 100118523 Form No. A0101, page 11 / 14 pages 1002031199-0 201248987, Its dielectric constant is between 1.5 and 3. 7. The thin film microstrip line band pass filter of claim 1, wherein the ground electrode is aluminum. 8. The thin film microstrip line bandpass filter of claim 1, wherein the filter unit is comprised of a plurality of one-half wavelength constrained line resonators. 100118523 Form No. A0101 Page 12 of 14 1002031199-0