Background technique
SAW device all plays a crucial role in various communication equipments, system, terminal.Its technical indicator
It is the key that communication equipment performance with characteristic.If wherein the sonic transmissions loss of material can significantly reduce, for communication equipment
Anti-interference ability and power consumption have significant increase.In the case where not changing the design of existing SAW device, pass through green wood
It is most important for modern communications equipment that the application of material realizes that transmission loss is greatly reduced.The frequency spectrum resource being becoming tight day now,
Device miniaturization, highly integrated, low in energy consumption, the technologies such as small of generating heat demand are also more more and more urgent.
Traditional SAW device is mainly made of matrix, piezoelectric membrane, interdigital electrode.Wherein, interdigital electrode passes through
Traditional integrated circuit technique on piezoelectric membrane by film deposition, photoetching, etch.Signal is input to side interdigital electrode
In, acoustic signals are converted by microwave signal through piezoelectric material and are transmitted in piezoelectric membrane, then in other side interdigital electrode
Microwave signal output is converted by acoustic signals by inverse piezoelectric effect.By piezoelectric membrane appropriate and electrode design, can make
The acoustic signals for meeting specific frequency requirement pass through, and realize resonance, filter function.Although traditional SAW device can also be realized
Filter function, but have a disadvantage that needs overcome:
1, larger, the sensitivity for the SAW device being made from it and anti-interference energy is lost in the sound wave of Conventional piezoelectric material
Power is substantially reduced.
2, it is caused using other materials incompatible with traditional integrated circuit technique, is not easy to realize large-scale serial production.
3, the diamond thin under non-patterned piezoelectric membrane, can only improve the response frequency of device, to device loss without
It is obviously improved.
Utility model content
For the shortcoming for overcoming prior art, the utility model provides a kind of sound table based on diamond matrix
Surface wave device.
To achieve the above object, the utility model provides following scheme:
A kind of SAW device based on diamond matrix, including diamond matrix, graphical piezoresistive material
Material and electrode;The diamond matrix is used for the transmission of surface acoustic wave;The graphical piezoelectric material is arranged described
On diamond matrix, the graphical piezoelectric material is for the conversion between microwave-sound wave;The graphical piezoelectric material
With a thickness of the 1/2 of resonant body wave length of sound;The electrode is arranged on the graphical piezoelectric material, and the electrode is for micro-
The input and output of wave;The polarity of the adjacent electrode is opposite.
Optionally, the material that the diamond matrix uses is monocrystalline or the high-purity rank diamond of polycrystalline.
Optionally, the graphical piezoelectric material is interdigital structure.
Optionally, diamond matrix is prepared using chemical vapour deposition technique.
Optionally, piezoelectric membrane and electrode are prepared using PVD deposition method.
Optionally, using semiconductor technology, by photoetching ,-ion etching-is removed photoresist-is protected and prepares graphical piezoelectric material.
Compared with prior art, the utility model has following technical effect that the utility model maintains conventional sound surface
The original microwave of wave device-sound wave conversion and microwave signal select characteristic;It is the main acoustic propagation of device using diamond
Medium, and then realize low-down device loss;Piezoelectric material and electrode forming are compatible with lsi technology.
On the basis of the features such as the utility model is easy to compatible with conventional device in the expansible optimization of device, simple process, sound table is realized
Surface wave devices use diamond reduces lossy microwave, can be applicable in various microwave radio components, equipment and system, as
High frequency, high-power, high-performance frequency-selecting device etc..It can be designed by piezoelectric material and telegraph circuit, realize different working modes, work
Working frequency, and operating mode and working frequency can be extended and change according to user demand, enhance device operating mode
And the diversity and flexibility of frequency.
Specific embodiment
The following will be combined with the drawings in the embodiments of the present invention, carries out the technical scheme in the embodiment of the utility model
Clearly and completely describe, it is clear that the described embodiments are only a part of the embodiments of the utility model, rather than whole
Embodiment.Based on the embodiments of the present invention, those of ordinary skill in the art are without making creative work
Every other embodiment obtained, fall within the protection scope of the utility model.
The purpose of the utility model is to provide a kind of SAW devices based on diamond matrix, utilize diamond
Material is the main sound bearing medium of device, and then realizes low-down device loss.
To keep the above objects, features, and advantages of the utility model more obvious and easy to understand, with reference to the accompanying drawing and have
Body embodiment is described in further detail the utility model.
As shown in Figure 1, the SAW device based on diamond matrix includes diamond matrix, graphical pressure
Electric material and electrode.The diamond matrix is used for the transmission of surface acoustic wave, what the diamond matrix used
Material is monocrystalline or the high-purity rank diamond of polycrystalline, and length, width and height size can be customized, and typical sizes are 3*3*0.5mm (platelet) or 3*
3*0.03mm (film, silicon are matrix), impurity N content are PPB rank, surface roughness Ra < 5nm.Using chemical vapor deposition
Method prepares diamond matrix.Diamond, for replacing the single piezoresistive material in conventional films SAW resonator
Material.Diamond is used as main sonic transmissions medium wherein, and optimal Acoustic Wave Propagation is provided for SAW device
Medium.
The graphical piezoelectric material is arranged on the diamond matrix, and the graphical piezoelectric material is interdigital
Structure, graphical piezoelectric material with a thickness of the 1/2 of resonant body wave length of sound λ.Graphical piezoelectric material exists for microwave-sound wave
It is mutually converted between piezoelectric material, the bulk acoustic wave for having excited corresponding frequencies through-thickness to propagate, different interdigital opposite in phase
Bulk acoustic wave has excited the surface acoustic wave of corresponding frequencies on its lower diamond matrix, realizes SAW device basic function.
Using semiconductor technology, by photoetching ,-ion etching-is removed photoresist-is protected and prepares graphical piezoelectric material.
The electrode is arranged on the graphical piezoelectric material, and the polarity of the adjacent electrode is opposite.Using PVD deposition
Method prepares piezoelectric membrane and electrode.The microwave signal for alternately applying or being formed opposite in phase on the electrode, for microwave
Input and output.
Surface acoustic wave circuit in the present embodiment is as shown in Fig. 2, be typical thin-film sound surface wave device circuit, piezoresistive material
Material shapes after photoetching, etching together with electrode, and interdigital width is also 1.7 microns.Physical circuit can be according to practical devices mode
And frequency is by client's self-defining.Imput output circuit is placed in chip two sides, and effect picture is shown in Fig. 3 after encapsulation.
The above structure realizes device to different frequencies by adjusting the geomery of piezoelectric material composition, thickness and figure
The response of the microwave spectrums such as rate, bandwidth, can be by designer's designed, designed.
The multilayered structure of the SAW device based on diamond matrix can self-supporting or with other substrates
Material is matrix, i.e., the above multilayered structure can using diamond as matrix realize self-supporting or multilayered structure in other substrate materials,
It is shaped on such as silicon material.
Using common microwave designing, simulation softward and microwave test instrument, mould can be carried out to this membrane structure-borne noise surface wave device
Quasi- and test, performance curve are shown in Fig. 4.Positive " n " shape curve is shown the S21 (transmission coefficient) of filter, and microwave is from input terminal
It is transmitted to the voltage ratio of output end, close to 0dB (logarithmic mode, ratio 1) near intermediate 1.75GHz, shows that microwave is believed
It number can pass completely through, be remarkably decreased below or above the microwave signal S21 of band connection frequency to -50dB and following, hence it is evident that inhibit, table
Bright microwave signal can not pass through.
The S11 (reflection coefficient) of filter is shown in " n " shape curve, there is more fluctuating in passband, and microwave is from input
End input back reflection returns the voltage ratio of input terminal, and maximum value is less than -20dB in passband, shows in passband almost without signal
Reflex to input terminal;Microwave signal S11 below or above band connection frequency is 0 (logarithmic mode, ratio 1), shows that signal is complete
Portion is reflected back input terminal.
According to specific embodiment provided by the utility model, the utility model discloses following technical effects: this is practical new
Type maintains the original microwave of conventional SAW device-sound wave conversion and microwave signal selects characteristic;Utilize diamond
For the main sound bearing medium of device, and then realize low-down device loss;Piezoelectric material and electrode forming and big rule
Vlsi die process compatible.The utility model is easy to compatible with conventional device, the spies such as simple process in the expansible optimization of device
On the basis of point, realizing SAW device using diamond reduces lossy microwave, can be applicable to various microwave radio portions
In part, equipment and system, as high frequency, high-power, high-performance frequency-selecting device etc..It can be set by piezoelectric material and telegraph circuit
Meter, realizes different working modes, working frequency, and operating mode and working frequency can according to user demand, be extended and
Change, enhances the diversity and flexibility of device operating mode and frequency.
Each embodiment in this specification is described in a progressive manner, the highlights of each of the examples are with other
The difference of embodiment, the same or similar parts in each embodiment may refer to each other.
Specific case used herein is expounded the principles of the present invention and embodiment, above embodiments
Explanation be merely used to help understand the method and its core concept of the utility model;Meanwhile for the general technology of this field
Personnel, based on the idea of the present invention, there will be changes in the specific implementation manner and application range.In conclusion
The content of the present specification should not be construed as a limitation of the present invention.