Semiconductor die
阅读说明：本技术 半导体管芯 (Semiconductor die ) 是由 A.范德西伊德 N.B.普费弗 Q.范沃尔斯特瓦德 P.施密特 于 2019-07-19 设计创作，主要内容包括：本发明描述了一种半导体管芯(1),包括至少第一发光二极管(L1)和第二发光二极管(L2),其中第一发光二极管(L1)包括形成在第一管芯区域(A1)中的第一二极管(D1)和沉积在第一管芯区域(A1)上的第一磷光体层(P1)；第二发光二极管(L2)包括第二二极管(D2)和沉积在第二管芯区域(A2)上的第二磷光体层(P2)；第一二极管(D1)和第二二极管(D2)反并联电连接；并且其中第二磷光体层(P2)的光学属性与第一磷光体层(P1)的光学属性不同。(semiconductor die (1) are described, comprising at least a light emitting diode (L1) and a second light emitting diode (L2), wherein the light emitting diode (L1) comprises a th diode (D1) formed in a th die area (A1) and a th phosphor layer (P1) deposited on the th die area (A1), the second light emitting diode (L2) comprises a second diode (D2) and a second phosphor layer (P2) deposited on the second die area (A2), the th diode (D1) and the second diode (D2) are electrically connected in anti-parallel, and wherein the optical properties of the second phosphor layer (P2) are different from the optical properties of the th phosphor layer (P1).)
1, semiconductor die (1) comprising at least a light emitting diode (L1) and a second light emitting diode (L2), wherein
-said th light emitting diode (L1) comprises a th diode (D1) formed in a th die area (a1) and a th phosphor layer (P1) deposited on said th die area (a 1);
-the second light emitting diode (L2) comprises a second diode (D2) and a second phosphor layer (P2) deposited on a second die area (a 2);
-the th diode (D1) and the second diode (D2) are electrically connected in anti-parallel, and wherein
-the optical properties of the second phosphor layer (P2) are different from the optical properties of the th phosphor layer (P1).
2. The semiconductor die of claim 1, wherein the th light emitting diode (L1) and the second light emitting diode (L2) emit electromagnetic radiation in different wavelength ranges.
3. The semiconductor die according to claim 2, wherein the wavelength difference (Δ λ) between the electromagnetic radiation emitted by the th light emitting diode (L1) and the electromagnetic radiation emitted by the second light emitting diode (L2) comprises at least 200 nm, more preferably at least 250 nm.
4. The semiconductor die of any of the preceding claims, wherein each diode (D1, D2) is provided as a transient voltage suppressor for another diodes (D1, D2).
5. The semiconductor die of any of the preceding claims, wherein light emitting diode (L1) emits electromagnetic radiation within the visible spectrum.
6. The semiconductor die of claim 5, wherein the phosphor layer (P1) of the visible spectrum light emitting diode (L1) comprises YAG: Ce, (Y, Lu) AG: Ce and (Ba, Sr)2Si5N8: Eu (BSSN), SR [ LiAl3N4 ]]Eu2+, Eu-activated Ba-Mg-aluminate, ZnS: Ag, Sr3MgSi2O8: Eu, Y3-xAl5-yGayO12:Cex(wherein 0.002)<x<0.12 and 0<=y<=0.4）、Sr1-x-yCaySiAlN3:Eux(wherein 0.001<x<0.03 and 0<=y<= 1) any of.
7. The semiconductor die according to any of the preceding claims, wherein both light emitting diodes (L1, L2) emit electromagnetic radiation within the visible spectrum.
8. The semiconductor die of claim 6, wherein the light emitting diode (L2) emits electromagnetic radiation in the infrared range.
9. The semiconductor die of claim 8 wherein the phosphor layer (P2) of the infrared spectrum light emitting diode (L2) comprises RE3Ga5-x-yAxSiO14:Cry(RE = La, Nd, Gd, Yb, Tm; A = Al, Sc) (wherein x is 0. ltoreq. x.ltoreq.1 and y is 0.005. ltoreq. y.ltoreq.0.1), Gd3-xRExSc2-y-zLnyGa3-wAlwO12:Crz(Ln = Lu, Y, Yb, Tm; RE = La, Nd) (wherein x is 0. ltoreq. x.ltoreq.3; Y is 0. ltoreq. y.ltoreq.1.5; z is 0. ltoreq. z.ltoreq.0.3; and w is 0. ltoreq. w.ltoreq.2), AAEM1-xF6:Crx(A = Li, Cu; AE = Sr, Ca; M = Al, Ga, Sc) (where 0.005. ltoreq. x. ltoreq.0.2), A2-x(WO4)3:Crx(A = Al, Ga, Sc, Lu, Yb) (wherein 0.003. ltoreq. x. ltoreq.0.5), Sc1-x-yAxBO3:Cry(A = Ga, Al, In, Lu, Y, Yb) (wherein 0. ltoreq. x.ltoreq.1 and 0.005. ltoreq. y.ltoreq.0.1) is .
10. The semiconductor die of claim 9, wherein both light emitting diodes (L1, L2) emit electromagnetic radiation in the red-infrared range.
11, a method of manufacturing a semiconductor die (1), comprising the steps of:
-forming a diode (D1) in an th die region (a1) and a second diode (D2) in a second die region (a2) such that the diode (D1) and the second diode (D2) are connected in anti-parallel;
-depositing a th phosphor layer (P1) on the th die area (A1) to complete a th light emitting diode (L1), and
-depositing a second phosphor layer (P2) on the second die area (a2) to complete a second light emitting diode (L2), wherein the optical properties of the second phosphor layer (P2) are different from the optical properties of the th phosphor layer (P1).
12. The method of claim 11, wherein said th die region (a1) is formed to include at least 50%, more preferably at least 75%, of the total die area.
13. Method according to claim 11 or 12, comprising the step of forming a separation layer (10) between the th light emitting diode (L1) and the second light emitting diode (L2).
14, electronic device (7) comprising an imaging module, and wherein the imaging module comprises an embodiment of the semiconductor die (1) according to any of claims 1 to 10 of .
15. The electronic device of claim 14, wherein the semiconductor die (1) is implemented as part of a camera flash arrangement (71) of the imaging module.
Technical Field
Semiconductor dies, methods of manufacturing semiconductor dies, and electronic devices having imaging modules including such semiconductor dies are described.
Background
Light Emitting Diodes (LEDs) include semiconductor junctions and thus may be damaged by electrostatic discharge (ESD) during processing at the manufacturing stage, and also damaged when part of of the circuit, methods of avoiding ESD damage to LEDs or string LEDs are to connect protection diodes in anti-parallel (also known as anti-parallel) in implementations the protection diodes are zener diodes.
The only purpose of the TVS diode in this anti-parallel arrangement is generally to transfer current from the reverse biased LED with very little ESD transient voltage the TVS diode accomplishes this functions only for a specific type of situation that is typically rare.
It is therefore an object of the present invention to provide circuits that avoid the problems outlined above.
Disclosure of Invention
The object of the invention is achieved by a semiconductor die according to
According to the present invention, a semiconductor die comprises at least a th light emitting diode and a second light emitting diode a p-n junction diode formed in a th die region and a th phosphor layer deposited on the th die region, and the second light emitting diode comprises a second p-n junction diode formed in a second die region and a second phosphor layer deposited on the second die region in the semiconductor die of the present invention, the th diode and the second diode are connected in anti-parallel, and the optical properties of the second phosphor layer are different from the optical properties of the th phosphor layer.
The optical properties ("emission properties") of the phosphor layer, i.e., whether it is up-converted or down-converted, the wavelength it absorbs, and the wavelength it emits, are determined in large part by the choice of phosphor material(s) and the second phosphor coating may have different or similar layer thicknesses.
In a preferred embodiment of the invention, the layer structure of the two p-n junction diodes is substantially identical, so that both diodes come from the same manufacturing process. In a particularly preferred embodiment of the invention, the diode may be implemented using InGaN as the light emitting layer, since InGaN is characterized by short wavelengths, resulting in excitation of two phosphor materials (e.g., visible and infrared). Alternatively, the diode may be implemented with AlGaAs/GaAs as the light emitting layer, since the material inherently emits in the infrared range and other wavelengths may be upconverted in a suitable phosphor layer, which may contain suitable crystals and/or nanoparticles.
In the context of the present invention, the term "light emitting diode" is to be understood as a combination of a p-n junction diode and a phosphor layer deposited on the p-n junction diode. A phosphor layer may be understood to comprise a single phosphor material or a combination of several phosphor materials. The phosphor layer performs wavelength conversion, i.e. it will absorb the electromagnetic radiation emitted by the p-n junction diode and emit the electromagnetic radiation at a different wavelength. In the following, it may be assumed that the phosphor layer has a down-conversion effect, i.e. the wavelength of the light emitted by the phosphor is longer than the wavelength of the electromagnetic radiation emitted by its p-n junction diode. Of course, the use of an up-converting phosphor layer is not excluded.
The present invention is based on the insight that in a circuit comprising anti-parallel connected diodes, each of the diodes can provide ESD protection for another diodes, and each diode can also have a function other than ESD protection, thus the semiconductor device of the present invention has two LEDs, each LED having a specific function other than ESD protection, i.e. each LED in an anti-parallel pair has a specific application function and provides ESD protection for another LEDs.
In accordance with the present invention, a method of fabricating a semiconductor die includes the steps of forming a p-n junction diode in an th die area and forming a second p-n junction diode in a second die area such that the th diode and the second diode are connected in anti-parallel, depositing a th phosphor layer on the th die area, and depositing a second phosphor layer on the second die area, wherein the composition of the second phosphor layer is different from the composition of the th phosphor layer.
In prior art devices including an LED and an anti-parallel TVS diode, the light emitting diode occupies a large portion of the die area, and the TVS diode occupies only a small portion of of the die area.
It is possible to obtain a dual function device simply by using a different phosphor material to cover the die area of the second p-n junction diode and driving either the th LED or the second LED as appropriate, whenever the second LED is activated (i.e., the th LED is reverse biased), the electromagnetic radiation emitted by the second p-n junction diode will be converted to a "useful" wavelength by the second phosphor layer, without significant changes to the epitaxial deposition process or die size.
According to the invention, an electronic device comprises an imaging module, and the imaging module comprises an embodiment of the semiconductor die of the invention. Because the semiconductor die is implemented to perform two functions (in addition to ESD protection), the imaging module of the electronic device of the present invention can be manufactured in an advantageously compact manner. Pairs of any two LEDs of a semiconductor die each perform a particular function, but since the LEDs are connected in anti-parallel, only two terminals or contacts (rather than four) are required. At the same time, each LED is protected from ESD damage from its opposite polarity "partner" LED.
The dependent claims and the following description disclose particularly advantageous embodiments and features of the invention the features of the embodiments may be combined as appropriate the features described in the context of the claim categories may equally be applied to the further claim categories.
In a particularly preferred embodiment of the invention, the th and second light emitting diodes emit electromagnetic radiation in different wavelength ranges, for example the diode/phosphor combination of the th light emitting diode may be realized to emit in the visible range and the diode/phosphor combination of the second light emitting diode may be realized to emit in the infrared or near infrared range preferably the wavelength difference between the electromagnetic radiation emitted by the th diode and the electromagnetic radiation emitted by the second diode comprises at least 100nm, wherein the wavelength difference may be understood to be measured between the mid-points of each range, for example in the case of the th diode with a visible emission peak of 550 nm and the second diode with an infrared emission peak of 850 nm the wavelength difference comprises 300 nm in the case of the th diode with a visible emission peak of 550 nm and the second diode with an infrared emission peak of 940 nm the wavelength difference comprises 390 nm.
For example, if the semiconductor die is to be used primarily as a light source, the th diode may be formed as a visible range emitting light emitting diode and the second diode may be formed as a TVS diode with the same epitaxial layers having the additional function of emitting in the near infrared, the th diode may be formed using 80% or more of the entire die while the second diode is implemented in the remaining volume, by selecting a suitable phosphor (e.g., a phosphor that converts blue wavelength to infrared wavelength), the additional function of the second diode (whose primary function is to provide TVS protection for the th LED) may be achieved the second diode is reverse biased and thus "on" when the or "primary" diode is reverse biased, and the infrared light emitted by the second LED may be used as a secondary infrared light source, such as a camera arrangement, or as a focused forward counterfeit detector in a product detection arrangement.
If an th diode is used as the light source in the visible spectrum, the p-n junction may be implemented to emit light in the wavelength range of 380 nm-470nm, and the phosphor layer applied to the th die area may include or more down-converting phosphors emitting in the range of 480 nm-800 nm.
Since the two emitting surfaces are side-by-side, a suitable optics arrangement may be used, such as "light recycling optics" that redirects angle light into a more compact beam.
In another embodiment, two light emitting diodes emit electromagnetic radiation in different regions of the infrared spectrum an application for such a device may be wavelength selective Li-Fi or face recognition, iris recognition, etc. for example, a th LED emitting at 940 nm may be used for face recognition and a second LED emitting at 850 nm may be used for iris recognition.
In another embodiment, a th diode emits in the visible spectrum and a second diode emits in the near infrared range the upconverting phosphor applied to the th die region will emit in the Ultraviolet (UV) range and the downconverting phosphor applied to the second die region emits in the Infrared (IR) range.
The method may include the step of forming a separation layer between the th die region and the second die region to prevent cross-talk.
For example, if the semiconductor die is to be used as a visible spectrum light source for a camera flash with additional functionality as a focusing auxiliary infrared light source, the th (visible spectrum emission) die area may be relatively larger than the second (infrared emission) die area.
In another implementations, series-connected LEDs or groups or parallel-connected LEDs may be protected by a single TVS diode, which is also implemented as a functional LED as described.
The semiconductor die of the present invention is well suited for use in space-constrained environments, such as in mobile devices such as smart phones.A device housing need only be designed to include a single aperture to expose both emitting areas of a single semiconductor die.A diode pair requires only two contact pads for the cathode and anode terminals.with a suitable multiplexer circuit, both functions of the semiconductor die can be implemented with a single driver, since only of the two diodes are active at any time.
As indicated above, the semiconductor die of the present invention may be used to advantage in a variety of applications.A camera flash is known to be designed to incorporate a visible emitting LED illuminating a scene and an IR emitting diode for focusing ancillary functions.A camera flash of this type may be implemented using an embodiment of the semiconductor die of the present invention implemented with a LED for visible emission and a second LED for infrared emission.
The semiconductor die of the present invention may also be incorporated into a two-color camera flash, such as a flash that uses two slightly different white tones in order to achieve a more natural lighting effect.
Similarly, a mobile device, such as a smartphone, may include an embodiment of the semiconductor die of the present invention and use the IR diode of the semiconductor die to implement IR remote control functions, Li-Fi functions, and the like.
As described above, if the ink used to print authentic documents or currency contains a phosphor that fluoresces in those range(s), such a device may be used to distinguish print counterfeits or counterfeit currency.
Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for the purposes of illustration and not as a definition of the limits of the invention.
Drawings
Fig. 1 shows a circuit diagram of an anti-parallel diode pair;
fig. 2 illustrates an embodiment of a semiconductor die of the present invention;
fig. 3 shows an exemplary spectral pair of an embodiment of a semiconductor die of the present invention;
fig. 4 and 5 show simplified plan views of embodiments of the semiconductor die of the present invention;
FIG. 6 shows an exemplary circuit diagram of an embodiment of the present invention;
fig. 7 shows an embodiment of the electronic device 7 according to the invention;
fig. 8 illustrates another exemplary embodiment of a semiconductor die of the present invention.
In the drawings, like numerals refer to like elements throughout, and the elements in the drawings are not drawn to scale.
Detailed Description
FIG. 1 shows an embodiment of the invention in which pairs of light emitting diodes L1, L2 are arranged in an anti-parallel configuration it may be assumed that the anti-parallel pairs are formed as a single die 1 (or "monolithic" die), as illustrated in FIG. 2. the st light emitting diode L1 is formed by applying a phosphor coating P1 over the th P-n junction diode D1 formed in the th die area, while the second light emitting diode L2 is formed by applying a second phosphor coating P2 over the second P-n junction diode D2 formed in the remaining die area. the material compositions of the P-n junction diodes D1, D2 and the phosphor layers P1, P2 are selected such that the light emitted when the th P-n junction D1 is forward biased is in a different wavelength range than the light emitted when the second P-n junction is forward biased.
Fig. 2 also indicates a
Fig. 3 shows an exemplary emission spectrum of an embodiment of a semiconductor die of the present invention having a wavelength λ (in nanometers [ nm ]) along the X-axis, and an emission amplitude (in arbitrary units [ au ]) along the Y-axis the light emitting diode L1 is implemented to emit light within the visible spectrum when forward biased, and the
Fig. 4 and 5 show simplified plan views of an embodiment of the semiconductor die 1 of the present invention fig. 4 shows an embodiment similar to fig. 2 above in which the region a1 dedicated to the th diode D1 is approximately 75% of the total die area and the TVS diode (e.g., also doubles as an infrared diode when the th LED is reverse biased) occupies the remaining 25% of the total die area fig. 5 shows a embodiment in which the region a1 dedicated to the th diode D1 is approximately 60% of the total die area and the second diode D2 occupies the remaining 40% of the total die area.
Fig. 6 shows an exemplary circuit diagram of an embodiment of the invention a die 1 comprising a reverse parallel pair of light emitting diodes L1, L2 is enclosed in a
Fig. 7 shows an embodiment of an electronic device 7 according to the invention, which device is a mobile phone comprising an imaging module, the figure shows a
Fig. 8 shows another exemplary embodiment of the semiconductor die 1 of the invention, in the upper part of the figure the
For the sake of clarity, it should be understood that the use of "" or "" throughout this application does not exclude a plurality, and "comprising" does not exclude other steps or elements.
Reference numerals
Semiconductor die 1
Separating
Light emitting diodes L1, L2
Diodes D1, D2
Phosphor layers P1, P2
Wavelength difference Delta lambda
th die area A1
Second die area A2
Die
Contact
Switches S1, S2, S3
Voltage sources V1, V2
Current sink C1
Electronic device 7
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