Manufacturing method of semiconductor device and semiconductor device structure

Abstract

The invention discloses a manufacturing method of a semiconductor device and a semiconductor device structure, and the method comprises the steps: providing a substrate which is provided with a first surface and a second surface which are opposite to each other, and the first surface comprises a first region and a second region; forming a sacrificial layer on the first surface of the substrate; removing the sacrificial layer in the first region; forming a dielectric film or an optical film on the surface of the sacrificial layer of the second region and the first region; removing the dielectric film or the optical film on the upper surface of the sacrificial layer in the second region; removing the sacrificial layer in the second region; a semiconductor epitaxial layer is formed on the second region of the substrate. According to the manufacturing method of the semiconductor device and the semiconductor device structure, epitaxial selected area growth can be achieved, self-passivation is achieved after epitaxial growth is completed, and the phenomenon that the exposed side face of an epitaxial material outside a selected area becomes a non-radiative recombination center or a side face electric leakage channel of a later photoelectric device can be effectively avoided.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor processes, and particularly relates to a manufacturing method of a semiconductor device and a semiconductor device structure. Background Art

[0002] With the development of telecommunications and data communication technologies, and the rise of artificial intelligence, the global data traffic has increased exponentially. Next-generation data centers, numerous high-performance computers, and emerging applications all have huge demands for high-speed data transmission, and there is an urgent need to overcome the existing data transmission bottleneck problem through fast, reliable, and low-cost optical links.

[0003] Due to the inherent property of the indirect bandgap of silicon materials, high-quality laser light sources cannot be provided. The current solution is still to integrate III-V materials or devices with optical gain functions onto a silicon substrate.

[0004] Hybrid integration of directly assembling III-V discrete lasers onto a silicon optical chip is the current mainstream commercial solution, but there are problems of high packaging cost and unsuitability for high-density integration.

[0005] The information disclosed in this background art section is only intended to enhance the overall understanding of the present invention and should not be regarded as an admission or any form of implication that this information constitutes prior art already known to those of ordinary skill in the art. Summary of the Invention

[0006] The object of the present invention is to provide a manufacturing method of a semiconductor device and a semiconductor device structure, which can achieve epitaxial selective growth and self-passivation after epitaxial growth is completed, and can effectively avoid the side of the epitaxial material exposed outside the selected area from becoming a non-radiative recombination center or a side leakage channel of a later optoelectronic device.

[0007] To achieve the above object, the technical solution provided by a specific embodiment of the present invention is as follows:

[0008] A manufacturing method of a semiconductor device, comprising:

[0009] Providing a substrate, the substrate having a first surface and a second surface disposed opposite to each other, the first surface including a first region and a second region;

[0010] Forming a sacrificial layer on the first surface of the substrate, the sacrificial layer covering the first region and the second region;

[0011] Removing the sacrificial layer in the first region to expose the first region of the substrate;

[0012] Form a dielectric film or an optical film on the sacrificial layer surface of the second region and the first region, where the sacrificial layer surface of the second region includes the upper surface and the side surface of the sacrificial layer in the second region;

[0013] Remove the dielectric film or the optical film on the upper surface of the sacrificial layer in the second region, exposing the upper surface of the sacrificial layer in the second region;

[0014] Remove the sacrificial layer in the second region, exposing the second region of the substrate;

[0015] Form a semiconductor epitaxial layer on the second region of the substrate.

[0016] In one or more embodiments of the present invention, the semiconductor epitaxial layer includes a single-layer film or a multi-layer film including an optical gain layer, where the height h from the center of the optical gain layer to the first surface of the substrate 1 is less than the thickness H of the semiconductor epitaxial layer.

[0017] In one or more embodiments of the present invention, the optical gain layer includes a single-layer or multi-layer quantum well layer, a single-layer or multi-layer quantum dot layer, and a multi-layer superlattice layer; and / or,

[0018] The optical gain layer includes GaAs / AlGaAs quantum well layers, InAlGaAs / InAlGaAs quantum well layers, InGaAsP / InGaAsP quantum well layers, GaAs / InGaAs quantum dot layers, InAs / GaSb superlattice layers.

[0019] In one or more embodiments of the present invention, the optical film is a multi-layer optical film, and the multi-layer optical film includes a high-reflection optical film layer and a low-reflection optical film layer. The manufacturing method further includes:

[0020] After forming the semiconductor epitaxial layer on the second region of the substrate, remove a part of the high-reflection optical film layer on a part of the side surface of the semiconductor epitaxial layer; and / or,

[0021] The optical film includes an antireflection optical film.

[0022] In one or more embodiments of the present invention, the manufacturing method further includes:

[0023] Form a stacked waveguide layer and an optical cladding layer on the first region of the substrate.

[0024] In one or more embodiments of the present invention, the height h from the center of the waveguide layer to the first surface of the substrate 2 is equal to the height h from the center of the optical gain layer to the first surface of the substrate 1 ; and / or,

[0025] The thickness t of the waveguide layer 2 is greater than the thickness t of the optical gain layer 1 and less than the thickness H of the semiconductor epitaxial layer; and / or,

[0026] The thickness t of the optical gain layer 1 is 10 nm - 500 nm.

[0027] In one or more embodiments of the present invention, the refractive index of the waveguide layer is n w2 ;

[0028] The refractive index n of the optical cladding layer w1 ;

[0029] The refractive index of the optical gain layer is n g ;

[0030] wherein, the refractive index relationship satisfies: 1 < n w1 < n w2 < n g .

[0031] In one or more embodiments of the present invention, the manufacturing method further includes:

[0032] forming a first electrode electrically connected to the substrate; and,

[0033] forming a second electrode electrically connected to the semiconductor epitaxial layer.

[0034] In one or more embodiments of the present invention, the included angle range between the side surface of the sacrificial layer in the second region and the first surface of the substrate is 80° - 100°; and / or

[0035] the thickness of the sacrificial layer is 200 nm - 5000 nm; and / or,

[0036] the lateral dimension of the sacrificial layer in the second region is 1 μm - 3000 μm.

[0037] In one or more embodiments of the present invention, the material of the dielectric film is different from the material of the sacrificial layer; and / or,

[0038] the dielectric film is non-conductive; and / or,

[0039] the dielectric film includes one of an alumina film, a silica film, and a silicon nitride film; and / or,

[0040] the thickness of the dielectric film is 20 nm - 2000 nm.

[0041] In one or more embodiments of the present invention, the optical thin film includes one or more laminated films of aluminum oxide thin film, titanium oxide thin film, silicon oxide thin film, silicon nitride thin film, zirconium oxide thin film, magnesium oxide thin film, yttrium oxide thin film, magnesium fluoride thin film, aluminum fluoride thin film, zinc sulfide thin film, zinc selenide thin film, and amorphous silicon thin film.

[0042] In one or more embodiments of the present invention, the optical thin film is a single-layer optical thin film, and the thickness l of the single-layer optical thin film 1 satisfies: l 1 = λ / 4 / n 1 ; where λ is the wavelength incident on the semiconductor device, and n 1 is the refractive index of the single-layer optical thin film.

[0043] In one or more embodiments of the present invention, the optical thin film is a multi-layer optical thin film, and the multi-layer optical thin film is formed by alternately stacking at least two single-layer optical thin films with different reflectivities. The thickness l of each single-layer optical thin film m satisfies: l m = λ / 4 / n m ; where λ is the wavelength incident on the semiconductor device, and n m is the refractive index of the corresponding single-layer optical thin film.

[0044] A semiconductor device structure includes:

[0045] A substrate having a first surface and a second surface disposed opposite to each other. The first surface includes a first region and a second region:

[0046] A semiconductor epitaxial layer formed on the second region of the first surface of the substrate;

[0047] A dielectric thin film or an optical thin film formed on the side surface of the semiconductor epitaxial layer in the second region and on the first region.

[0048] In one or more embodiments of the present invention, the semiconductor device structure further includes:

[0049] A first electrode electrically connected to the substrate;

[0050] A second electrode electrically connected to the semiconductor epitaxial layer.

[0051] In one or more embodiments of the present invention, the semiconductor device structure further includes a waveguide layer formed on the dielectric thin film or the optical thin film on the first region of the substrate.

[0052] In one or more embodiments of the present invention, the height h from the center of the waveguide layer to the first surface of the substrate 2 is equal to the height h from the center of the optical gain layer to the first surface of the substrate1 ; and / or,

[0053] The thickness t of the waveguide layer 2 is greater than the thickness t of the optical gain layer 1 and less than the thickness H of the semiconductor epitaxial layer.

[0054] In one or more embodiments of the present invention, the optical thin film is a multi-layer optical thin film;

[0055] The number of layers of the optical thin film on a partial side surface of the semiconductor epitaxial layer in the second region is less than the number of layers of the optical thin film on the remaining side surfaces of the semiconductor epitaxial layer; and / or,

[0056] The optical thin film includes an anti-reflection optical thin film.

[0057] Compared with the prior art, the manufacturing method of the semiconductor device and the semiconductor device structure of the present invention can achieve a large wafer size at a lower substrate cost by fabricating a dielectric film layer or an optical film layer as a mask pattern on a large-sized substrate and using the mask pattern for area-selective epitaxial growth of III-V semiconductor materials, and also has the advantages of small device size and high integration degree.

[0058] The manufacturing method of the semiconductor device and the semiconductor device structure of the present invention have a pre-definable mask pattern, can achieve self-passivation after growth is completed, and can effectively prevent the side surface of the epitaxial material exposed outside the selected area from becoming a non-radiative recombination center or a side leakage channel of the later optoelectronic device.

[0059] The manufacturing method of the semiconductor device and the semiconductor device structure of the present invention form a composite optical thin film mask pattern structure composed of multiple optical film layers, which has an optical function for a specific wavelength, including high reflection, low reflection or anti-reflection functions at a specific optical wavelength. Through the combination of optical film layers with high reflection, low reflection and anti-reflection functions, and combined with the optically gain layer grown epitaxially, optical gain and controllable side light emission can be achieved, which is suitable for manufacturing devices such as semiconductor lasers and optical amplifiers.

[0060] Different from the conventional semiconductor edge-emitting laser and optical amplifier processes, which require natural cleavage of the epitaxial wafer and then two-side optical coating on the side surfaces respectively, the manufacturing method of the semiconductor device and the semiconductor device structure of the present invention can achieve an optical cavity with high reflection on both sides at the end of epitaxial growth. By adjusting the composite optical thin film mask pattern structure on one side, asymmetrical optical reflection on both sides can be achieved, thereby controlling the light emission direction. In addition, in the light transmission direction, multiple waveguide layers can be deposited and precisely integrated according to the position of the epitaxial optical gain layer, further realizing the multi-material system monolithic photon integration function of lasers, optical amplifiers and optical waveguides. Description of the Drawings

[0061] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments recorded in the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on these drawings.

[0062] Figure 1 It is a process flow chart of the manufacturing method of a semiconductor device in the first embodiment of the present invention;

[0063] Figures 2a - 2g It is a process step diagram of the manufacturing method of a semiconductor device in the first embodiment of the present invention;

[0064] Figure 3 It is a process flow chart of the manufacturing method of a semiconductor device in the second embodiment of the present invention;

[0065] Figures 4a - 4i It is a process step diagram of the manufacturing method of a semiconductor device in the second embodiment of the present invention;

[0066] Figure 5 It is a process flow chart of the manufacturing method of a semiconductor device in the third embodiment of the present invention;

[0067] Figures 6a - 6j It is a process step diagram of the manufacturing method of a semiconductor device in the third embodiment of the present invention. Detailed Embodiments

[0068] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0069] As Figure 1 shown, the first embodiment of the present invention provides a method for manufacturing a semiconductor device, which specifically includes the following steps:

[0070] S1. Provide a substrate, the substrate has a first surface and a second surface arranged opposite to each other, and the first surface includes a first region and a second region.

[0071] As Figure 2aAs shown, a substrate 10 is provided. The substrate 10 is preferably a conductive single crystal substrate or a single crystal - buried oxide layer composite substrate. The substrate 10 has a first surface 10a and a second surface 10b which are oppositely arranged. The first surface 10a of the substrate 10 includes a first region A and a second region B. It can be understood that the first region A and the second region B may constitute the entire first surface of the substrate 10; or they may constitute a part of the first surface of the substrate 10, that is, the first surface of the substrate 10 may further include other regions, such as a third region or a fourth region, and the present application does not limit this. It can be understood that the division of the regions on the first surface can be determined according to the pattern and type of the semiconductor epitaxial layer to be grown subsequently.

[0072] S2, form a sacrificial layer on the first surface of the substrate, and the sacrificial layer covers the first region and the second region.

[0073] As Figure 2b shown, a sacrificial layer 20 is formed on the first surface 10a of the substrate 10. The sacrificial layer 20 at least completely covers the first region A and the second region B. The material of the sacrificial layer 20 may include polysilicon, silicon oxide (SiO 2 ), silicon nitride (Si 3 N 4 ), polyimide, photoresist, etc. The thickness range of the sacrificial layer 20 is 200 nm - 5000 nm, which is consistent with the thickness H of the semiconductor epitaxial layer to be grown subsequently by epitaxy.

[0074] S3, remove the sacrificial layer in the first region to expose the first region of the substrate.

[0075] As Figure 2c shown, preferably, micro - processing techniques such as photolithography and etching can be used to remove the sacrificial layer 20 in the first region A until the first region A of the first surface 10a of the substrate 10 is completely exposed. The included angle between the side surface of the sacrificial layer 20 in the remaining second region B and the first surface 10a of the substrate 10 is in the range of 80° - 100°. The lateral dimension of the sacrificial layer 20 in the remaining second region B is consistent with the lateral dimension of the semiconductor epitaxial layer to be grown subsequently by epitaxy, and the dimension range is 1 μm - 3000 μm.

[0076] It can be understood that the first region A and the second region B can be delimited according to the pattern and type of the semiconductor epitaxial layer to be grown subsequently. The partial removal of the sacrificial layer 20 patterns the sacrificial layer 20, enabling a subsequent dielectric thin film to be deposited in the region where the sacrificial layer 20 has been removed, and the deposition of the dielectric thin film further defines the range of the semiconductor epitaxial layer to be grown subsequently.

[0077] S4. A dielectric thin film is formed on the surface of the sacrificial layer in the second region and the first region. The surface of the sacrificial layer in the second region includes the upper surface and the side surfaces of the sacrificial layer in the second region.

[0078] In order to achieve self-passivation immediately after the subsequent epitaxial growth is completed, as Figure 2d shown, on the patterned sacrificial layer 20 (after removing the sacrificial layer 20 in the first region A, the entire sacrificial layer 20 has been patterned), a dielectric thin film 30 made of a material different from that of the sacrificial layer 20 and non-conductive is deposited. Specifically, the dielectric thin film 30 is deposited on the upper surface, the side surfaces of the sacrificial layer 20, and the first region A after removing the sacrificial layer 20. This dielectric thin film 30 can directly serve as the passivation layer for the subsequent semiconductor epitaxial layer, achieving self-passivation after the epitaxy is completed. The material of the dielectric thin film 30 can include aluminum oxide (Al 2 O 3 ), silicon oxide (SiO 2 ), and silicon nitride (Si 3 N 4 ), etc., and the thickness range is 20 nm - 2000 nm. The setting of the dielectric thin film 30 can achieve side surface self-passivation of the subsequent required semiconductor epitaxial layer, reducing non-radiative recombination and side surface leakage of the side surfaces of the semiconductor epitaxial layer.

[0079] S5. Remove the dielectric thin film on the upper surface of the sacrificial layer in the second region, exposing the upper surface of the sacrificial layer in the second region.

[0080] As Figure 2e shown, all the dielectric thin film 30 on the upper surface of the sacrificial layer 20 in the second region B can be removed by chemical mechanical polishing or other methods, but the dielectric thin film on the side surfaces of the sacrificial layer 20 in the second region B is retained, exposing the upper surface of the sacrificial layer 20 in the second region B.

[0081] S6. Remove the sacrificial layer in the second region, exposing the second region of the substrate.

[0082] As Figure 2f shown, the remaining sacrificial layer 20 on the second region B is removed by dry etching or wet etching, exposing the second region B of the substrate 10. After the sacrificial layer 20 is removed, a pattern composed of the side edges (the part of the dielectric thin film formed on the side surfaces of the sacrificial layer in the second region) and the bottom edges (the part of the dielectric thin film formed on the surface of the first region) with the height of the dielectric thin film 30 being consistent with the thickness H of the subsequent required semiconductor epitaxial layer is retained on the substrate 10, constituting a mask pattern or a mask pattern array for defining the range of the subsequent required semiconductor epitaxial layer.

[0083] S7. Form a semiconductor epitaxial layer on the second region of the substrate.

[0084] AsFigure 2g As shown, epitaxial growth of a compound semiconductor material is carried out on the region where the first surface of the substrate 10 is exposed between the mask patterns or the mask pattern array, to form a semiconductor epitaxial layer 40 grown in a selected area. The thickness H of the semiconductor epitaxial layer ranges from 200 nm to 5000 nm. The effective refractive index of the semiconductor epitaxial layer 40 should be greater than 3.

[0085] In this first embodiment, the semiconductor epitaxial layer 40 can be a single-layer thin film or a multi-layer thin film including an optical gain layer. The thickness t 1 of the optical gain layer is 10 nm to 500 nm. The height h from the center of the optical gain layer to the first surface 10a of the substrate 10 1 is less than the thickness H of the semiconductor epitaxial layer 40.

[0086] The optical gain layer includes low-dimensional quantum structures such as single-layer or multi-layer quantum well layers, single-layer or multi-layer quantum dot layers, and multi-layer superlattice layers. And / or, the optical gain layer includes GaAs / AlGaAs quantum well layers, InAlGaAs / InAlGaAs quantum well layers, InGaAsP / InGaAsP quantum well layers, GaAs / InGaAs quantum dot layers, InAs / GaSb superlattice layers, etc., which have the function of optical absorption or optical gain at specific wavelengths and can be used to form optoelectronic devices such as detectors, lasers, and optical amplifiers.

[0087] This first embodiment also provides a semiconductor device structure, including:

[0088] A substrate having a first surface and a second surface disposed opposite to each other, and the first surface includes a first region and a second region.

[0089] A semiconductor epitaxial layer formed on the second region of the first surface of the substrate. The semiconductor epitaxial layer includes a single-layer thin film or a multi-layer thin film including an optical gain layer. The optical gain layer includes single-layer or multi-layer quantum well layers, single-layer or multi-layer quantum dot layers, and multi-layer superlattice layers; and / or, the optical gain layer includes GaAs / AlGaAs quantum well layers, InAlGaAs / InAlGaAs quantum well layers, InGaAsP / InGaAsP quantum well layers, GaAs / InGaAs quantum dot layers, InAs / GaSb superlattice layers.

[0090] A dielectric thin film formed on the side surface and the first region of the semiconductor epitaxial layer in the second region.

[0091] When the semiconductor epitaxial layer is a multi-layer thin film including an optical gain layer, the semiconductor device structure can further include a waveguide layer formed on the dielectric thin film on the first region of the substrate. And

[0092] The first electrode and the second electrode, the first electrode is electrically connected to the substrate; the second electrode is electrically connected to the semiconductor epitaxial layer.

[0093] Example 1:

[0094] A 6-μm-thick SiO layer (sacrificial layer) was formed on an 8-inch Si(001) substrate by low-frequency plasma chemical vapor deposition. 2 layer (sacrificial layer).

[0095] A mesa array with a center pitch of 120 μm (this mesa array is the reserved sacrificial layer) was fabricated by ultraviolet lithography and high-density plasma dry etching. The mesa width is 100 μm, and the angle between the side surface of the mesa and the substrate surface is 93 degrees. The etched area needs to be over-etched to ensure the exposure of the silicon substrate surface.

[0096] A 600-nm-thick Si layer (dielectric thin film) was deposited on the patterned SiO layer (including the upper surface and the side surface) and the exposed substrate surface by plasma-enhanced chemical vapor deposition. Subsequently, the 600-nm-thick Si layer on the upper surface of the SiO layer was completely removed by chemical mechanical polishing, exposing the upper surface of the SiO layer, and the Si layer on the side surface of the SiO layer and the Si layer on the substrate surface connected to the Si layer on the side surface of the SiO layer were retained. 2 layer (including the upper surface and the side surface) and the exposed substrate surface was deposited with a 600-nm-thick Si 3 N 4 layer (dielectric thin film). Subsequently, the 600-nm-thick Si 2 layer on the upper surface of the SiO 3 N 4 layer was completely removed, exposing the upper surface of the SiO 2 layer, and the Si 2 layer on the side surface of the SiO 3 N 4 layer and the Si 2 layer on the substrate surface connected to the Si 3 N 4 layer connected to the Si 3 N 4 layer.

[0097] All the remaining SiO layers were completely removed by HF gas or solution, and the epitaxial growth mask pattern was formed by the retained Si 2 layer. 3 N 4 layer.

[0098] After chemically cleaning and drying the silicon substrate with the mask pattern, it was placed in metalorganic chemical vapor deposition to grow a 6-μm-thick GaAs layer (semiconductor epitaxial layer).

[0099] During epitaxial growth, the GaAs layer will selectively grow on the surface of the silicon substrate not covered by the Si 3 N 4 layer. After growth, the height of the GaAs layer is basically flush with the maximum height of the Si 3 N 4 layer, and the Si 3N 4 The layer naturally forms a side passivation on the GaAs semiconductor epitaxial layer terrace.

[0100] like Figure 3 As shown, the second embodiment of the present invention provides another method for manufacturing a semiconductor device, which specifically includes the following steps:

[0101] S10, providing a substrate, wherein the substrate has a first surface and a second surface arranged opposite to each other, and the first surface includes a first region and a second region.

[0102] like Figure 4a As shown, a substrate 10 is provided. The substrate 10 is preferably a conductive single crystal substrate or a single crystal-buried oxide layer composite substrate. The substrate 10 has a first surface 10a and a second surface 10b arranged opposite to each other. The first surface 10a of the substrate 10 includes a first region A and a second region B. It can be understood that the first region A and the second region B can constitute the entire first surface of the substrate 10, or can constitute a portion of the first surface of the substrate 10, that is, the first surface of the substrate 10 can also include other regions, such as a third region or a fourth region, and the present application does not limit this. It can be understood that the division of the regions on the first surface can be determined according to the pattern and type of the semiconductor epitaxial layer to be grown subsequently.

[0103] S20, forming a sacrificial layer on the first surface of the substrate, wherein the sacrificial layer covers the first region and the second region.

[0104] like Figure 4b As shown, a sacrificial layer 20 is formed on the first surface 10a of the substrate 10. The sacrificial layer 20 at least completely covers the first region A and the second region B. The material of the sacrificial layer 20 may include polysilicon, silicon oxide (SiO 2 ), silicon nitride (Si 3 N 4 ), polyimide and photoresist, etc. The thickness of the sacrificial layer 20 ranges from 200 nm to 5000 nm, which is consistent with the thickness H of the semiconductor epitaxial layer to be subsequently grown epitaxially.

[0105] S30, removing the sacrificial layer in the first region to expose the first region of the substrate.

[0106] like Figure 4c As shown, preferably, the sacrificial layer 20 in the first region A can be removed by micro-machining processes such as photolithography and etching until the first region A of the first surface 10a of the substrate 10 is completely exposed. The angle between the side surface of the sacrificial layer 20 in the retained second region B and the first surface 10a of the substrate 10 is in the range of 80°-100°. The lateral dimensions of the sacrificial layer 20 in the retained second region B are consistent with the lateral dimensions of the semiconductor epitaxial layer to be subsequently epitaxially grown, and the dimension range is 1 μm-3000 μm.

[0107] It is understandable that the first region A and the second region B can be delimited according to the pattern and type of the semiconductor epitaxial layer required for subsequent epitaxial growth. The partial removal of the sacrificial layer 20 patterns the sacrificial layer 20, enabling the subsequent single-layer optical film to be deposited in the region where the sacrificial layer 20 has been removed, and the deposition of the single-layer optical film further defines the scope of the semiconductor epitaxial layer required for subsequent epitaxial growth.

[0108] S40. A single-layer optical film is formed on the surface of the sacrificial layer in the second region and the first region. The surface of the sacrificial layer in the second region includes the upper surface and the side surface of the sacrificial layer in the second region.

[0109] As Figure 4d shown, on the patterned sacrificial layer 20 (after removing the sacrificial layer 20 in the first region A, the entire sacrificial layer 20 is patterned), a non-conductive single-layer optical film 300 made of a material different from that of the sacrificial layer 20 is deposited. Specifically, the optical film 300 is deposited on the upper surface, the side surface of the sacrificial layer 20, and the first region A after removing the sacrificial layer 20. The material of the optical film 300 may include aluminum oxide (Al 2 O 3 ), titanium oxide (TiO 2 ), silicon oxide (SiO 2 ), silicon nitride (Si 3 N 4 ), zirconium oxide (ZrO 2 ), magnesium oxide (MgO), yttrium oxide (Y 2 O 3 ), magnesium fluoride (MgF 2 ), aluminum fluoride (AlF 3 ), zinc sulfide (ZnS), zinc selenide (ZnSe), amorphous silicon, etc., and the thickness range is 20 nm - 2000 nm. By setting the thickness of the optical film 300, optical functions such as reflection or antireflection of a specific wavelength are achieved.

[0110] Among them, the thickness l 1 of the single-layer optical film 300 satisfies: l 1 = λ / 4 / n 1 ; where λ is the wavelength incident on the semiconductor device, and n 1 is the refractive index of the single-layer optical film. Preferably, the single-layer optical film 300 has an antireflection function. At the wavelength λ incident on the semiconductor device, the refractive index of the single-layer optical film 300 with antireflection function needs to be as close as possible to the square root of the average refractive index n s of the substrate 10 or the semiconductor epitaxial layer 40.

[0111] S50, Remove the single-layer optical thin film on the upper surface of the sacrificial layer in the second region, exposing the upper surface of the sacrificial layer in the second region.

[0112] As Figure 4e shown, a chemical mechanical polishing method or other method can be used to remove all the optical thin films 300 on the upper surface of the sacrificial layer 20 in the second region B, but the optical thin films on the side surfaces of the sacrificial layer 20 in the second region B are retained, exposing the upper surface of the sacrificial layer 20 in the second region B.

[0113] S60, Remove the sacrificial layer in the second region, exposing the second region of the substrate.

[0114] As Figure 4f shown, a dry etching or wet etching method is used to remove the remaining sacrificial layer 20 on the second region B, exposing the second region B of the substrate 10. After the sacrificial layer 20 is removed, a pattern composed of the side edges (the optical thin film part formed on the side surface of the sacrificial layer in the second region) and the bottom edges (the optical thin film part formed on the surface of the first region) with the height of the optical thin film 300 being consistent with the thickness H of the subsequently required epitaxially grown semiconductor epitaxial layer is retained on the substrate 10, constituting a mask pattern or a mask pattern array that defines the range of the subsequently required epitaxially grown semiconductor epitaxial layer.

[0115] S70, Form a semiconductor epitaxial layer on the second region of the substrate.

[0116] As Figure 4g shown, epitaxial growth of a compound semiconductor material is carried out on the region of the first surface of the substrate 10 exposed between the mask pattern or the mask pattern array to form a selectively grown semiconductor epitaxial layer 40. The thickness H of the semiconductor epitaxial layer ranges from 200 nm to 5000 nm. The effective refractive index of the semiconductor epitaxial layer 40 should be greater than 3 and greater than the refractive index n of the optical thin film 300 1 .

[0117] The semiconductor epitaxial layer 40 can include a multi-layer thin film containing an optical gain layer. The thickness t 1 of the optical gain layer is 10 nm to 500 nm. The height h 1 from the center of the optical gain layer to the first surface 10a of the substrate 10 is less than the thickness H of the semiconductor epitaxial layer 40.

[0118] The optical gain layer includes low-dimensional quantum structures such as single or multiple quantum well layers, single or multiple quantum dot layers, and multiple superlattice layers. And / or, the optical gain layer includes GaAs / AlGaAs quantum well layers, InAlGaAs / InAlGaAs quantum well layers, InGaAsP / InGaAsP quantum well layers, GaAs / InGaAs quantum dot layers, InAs / GaSb superlattice layers, etc., which have the function of optical absorption or optical gain at specific wavelengths and can be used to form optoelectronic devices such as detectors, lasers, and optical amplifiers.

[0119] The optical thin film 300 with an antireflection function is located on the side surface of the semiconductor epitaxial layer 40 containing the optical gain layer, and can achieve the optical transmission function at specific wavelengths.

[0120] S80, a waveguide layer and an optical cladding layer are formed in a stacked manner on the first region of the substrate.

[0121] As Figure 4h shown, the non-conductive optical cladding layers 60 with different refractive indices and the waveguide layer 50 are alternately deposited. Preferably, the waveguide layer 50 is located between two optical cladding layers 60. Among them, the refractive index of the waveguide layer 50 is n w2 , the refractive index of the optical cladding layer 60 is n w1 , and the refractive index of the optical gain layer in the semiconductor epitaxial layer 40 is n g , and the refractive index relationship among the three needs to satisfy 1 < n w1 < n w2 < n g .

[0122] When depositing the optical cladding layer 60 and the waveguide layer 50 with different refractive indices, precise alignment between the waveguide layer 50 for optical transmission and the optical gain layer in the semiconductor epitaxial layer 40 is required. Thus, the height h 2 of the center position of the waveguide layer 50 from the first surface 10a of the substrate 10 should be equal to the height h 1 of the center of the optical gain layer from the first surface 10a of the substrate 10. The thickness t 2 of the waveguide layer 50 is greater than or equal to the thickness t 1 of the optical gain layer and less than the thickness H of the semiconductor epitaxial layer 40.

[0123] It can be understood that during the deposition process of the optical cladding layer 60 and the waveguide layer 50, a certain amount of the optical cladding layer 60 and the waveguide layer 50 will also be deposited on the upper surface of the semiconductor epitaxial layer 40. Therefore, it is necessary to remove the waveguide layer 50 and the optical cladding layer 60 on the upper surface of the semiconductor epitaxial layer 40 to flatten the surface and expose the upper surface of the semiconductor epitaxial layer 40, facilitating the preparation of subsequent electrodes.

[0124] S90, forming a first electrode electrically connected to the substrate; and, forming a second electrode electrically connected to the semiconductor epitaxial layer.

[0125] As Figure 4i shown, a second electrode 72 is fabricated on the upper surface of the semiconductor epitaxial layer 40 and the second electrode 72 completely covers the upper surface of the semiconductor epitaxial layer 40. The substrate 10 is thinned, and a first electrode 71 is fabricated on the second surface 10b of the substrate 10.

[0126] In this second embodiment, a semiconductor device structure is further provided, including:

[0127] A substrate having a first surface and a second surface disposed opposite to each other, the first surface including a first region and a second region.

[0128] A semiconductor epitaxial layer formed on the second region of the first surface of the substrate. The semiconductor epitaxial layer includes a single-layer thin film or a multi-layer thin film including an optical gain layer. The optical gain layer includes a single-layer or multi-layer quantum well layer, a single-layer or multi-layer quantum dot layer, and a multi-layer superlattice layer; and / or, the optical gain layer includes a GaAs / AlGaAs quantum well layer, an InAlGaAs / InAlGaAs quantum well layer, an InGaAsP / InGaAsP quantum well layer, a GaAs / InGaAs quantum dot layer, an InAs / GaSb superlattice layer.

[0129] A single-layer optical thin film formed on the side surface and the first region of the semiconductor epitaxial layer in the second region.

[0130] When the semiconductor epitaxial layer is a multi-layer thin film including an optical gain layer, the semiconductor device structure may further include a waveguide layer formed on the single-layer optical thin film on the first region of the substrate. And,

[0131] A first electrode and a second electrode, the first electrode being electrically connected to the substrate; the second electrode being electrically connected to the semiconductor epitaxial layer.

[0132] Example 2

[0133] A polyimide layer (sacrificial layer) with a thickness of 3 μm is spin-coated on a 12-inch n-type Si(001) substrate.

[0134] The polyimide layer is fabricated into a mesa with a width of 600 μm (this mesa is the reserved sacrificial layer) by using ultraviolet lithography and reactive ion etching. The angle between the side surface of the mesa and the substrate surface is 90 degrees. The etched area needs to be over-etched to ensure that the silicon substrate surface is exposed.

[0135] One layer of 187 nm Al 2 O 3Optical antireflection film (single-layer optical film), with a target light-transmitting center wavelength of 1310 nm. Subsequently, chemical mechanical polishing is used to completely remove the 187-nm-thick Al on the upper surface of the polyimide layer 2 O 3 Optical antireflection film, exposing the upper surface of the polyimide and retaining the Al on the side surface of the polyimide layer 2 O 3 Optical antireflection film and the Al on the substrate surface and on the side surface of the polyimide layer 2 O 3 Al connected to the optical antireflection film 2 O 3 Optical antireflection film.

[0136] Use N-methylpyrrolidone solvent to completely remove all the remaining polyimide layer, and the retained Al 2 O 3 Optical antireflection film constitutes an epitaxial growth mask pattern.

[0137] After chemically cleaning and drying the silicon substrate with the mask pattern, it is placed in metalorganic chemical vapor deposition, and an n-type InP / InAlAs superlattice buffer layer, an InGaAsP optical confinement layer, an InGaAsP / InGaAsP multiple quantum well, an InGaAsP optical confinement layer, a p-type InP cap layer, and a p-type InGaAs contact layer (collectively constituting a semiconductor epitaxial layer) with a total thickness of 3.2 μm are grown in sequence. Among them, the total thickness of the InGaAsP / InGaAsP multiple quantum well is 100 nm, and the center is 1.3 μm away from the first surface of the substrate.

[0138] During epitaxial growth, multiple epitaxial films such as InP / InGaAsP / InGaAs are selectively grown on the surface of the silicon substrate not covered by the Al 2 O 3 Optical antireflection film. After growth, the surface of the semiconductor epitaxial layer is flush with the maximum height of the Al 2 O 3 Optical antireflection film.

[0139] Subsequently, an optical coating layer / waveguide layer / optical coating layer of 813 nm SiO 2 / 600 nm Si 3 N 4 / 1600 nm SiO 2 is deposited in sequence. Chemical mechanical polishing is used to remove all the optical coating layer and waveguide layer on the upper surface of the semiconductor epitaxial layer to flatten the surface and expose the upper surface of the semiconductor epitaxial layer.

[0140] Deposit the upper electrode metal (the second electrode) on the upper surface of the semiconductor epitaxial layer, and the upper electrode metal completely covers the upper surface of the semiconductor epitaxial layer. After thinning the substrate to 200 μm, deposit the lower electrode metal (the first electrode) on the surface of the substrate facing away from the semiconductor epitaxial layer. The upper electrode metal and the lower electrode metal are located on the upper and lower sides of the device structure, and the optical amplifier device is fabricated.

[0141] After the optical amplifier device is fabricated, it operates under the bias voltage of the upper electrode metal and the lower electrode metal. The input laser passes through one side of the Al 2 O 3 optical antireflection thin film, enters the region near the quantum well, and after multiple reflections and amplifications, it is output from the other side. The amplified laser enters the Si 3 N 4 waveguide layer for transmission.

[0142] As Figure 5 shown, the third embodiment of the present invention provides a method for fabricating a semiconductor device, which specifically includes the following steps:

[0143] S100, provide a substrate, the substrate has a first surface and a second surface arranged opposite to each other, and the first surface includes a first region and a second region.

[0144] As Figure 6a shown, provide the substrate 10. The substrate 10 is preferably a conductive single-crystal substrate or a single-crystal-buried oxide layer composite substrate. The substrate 10 has a first surface 10a and a second surface 10b arranged opposite to each other. The first surface 10a of the substrate 10 includes a first region A and a second region B. It can be understood that the first region A and the second region B can constitute the entire first surface of the substrate 10, or can constitute a part of the first surface of the substrate 10, that is, the first surface of the substrate 10 can also include other regions, such as a third region or a fourth region, and the present application does not limit this. It can be understood that the division of the regions on the first surface can be determined according to the pattern and type of the semiconductor epitaxial layer to be grown subsequently.

[0145] S200, form a sacrificial layer on the first surface of the substrate, and the sacrificial layer covers the first region and the second region.

[0146] As Figure 6b shown, form a sacrificial layer 20 on the first surface 10a of the substrate 10. The sacrificial layer 20 at least completely covers the first region A and the second region B. The material of the sacrificial layer 20 can include polysilicon, silicon oxide (SiO 2 ), silicon nitride (Si 3 N 4 ), polyimide, photoresist, etc. The thickness range of the sacrificial layer 20 is 200 nm - 5000 nm, which is consistent with the thickness H of the semiconductor epitaxial layer to be grown subsequently.

[0147] S300, Remove the sacrificial layer in the first region, exposing the first region of the substrate.

[0148] As Figure 6c shown, preferably, microfabrication processes such as photolithography and etching can be used to remove the sacrificial layer 20 in the first region A until the first region A of the first surface 10a of the substrate 10 is completely exposed. The included angle between the side surface of the sacrificial layer 20 in the remaining second region B and the first surface 10a of the substrate 10 ranges between 80° and 100°. The lateral dimension of the sacrificial layer 20 in the remaining second region B is consistent with the lateral dimension of the semiconductor epitaxial layer to be epitaxially grown subsequently, and the dimension range is 1 μm - 3000 μm.

[0149] It can be understood that the first region A and the second region B can be delimited according to the pattern and type of the semiconductor epitaxial layer to be epitaxially grown subsequently. Partial removal of the sacrificial layer 20 patterns the sacrificial layer 20, enabling subsequent multi-layer optical films to be deposited in the region where the sacrificial layer 20 has been removed, and the deposition of the multi-layer optical films further defines the range of the semiconductor epitaxial layer to be epitaxially grown subsequently.

[0150] S400, Form a multi-layer optical film on the surface of the sacrificial layer in the second region and on the first region. The surface of the sacrificial layer in the second region includes the upper surface and the side surface of the sacrificial layer in the second region.

[0151] As Figure 6d shown, on the patterned sacrificial layer 20 (after removing the sacrificial layer 20 in the first region A, the entire sacrificial layer 20 is patterned), deposit a non-conductive multi-layer optical film 300b made of a material different from that of the sacrificial layer 20. Specifically, the multi-layer optical film 300b is deposited on the upper surface, the side surface of the sacrificial layer 20, and on the first region A after removing the sacrificial layer 20. The material of the multi-layer optical film 300b can include aluminum oxide (Al 2 O 3 ), titanium oxide (TiO 2 ), silicon oxide (SiO 2 ), silicon nitride (Si 3 N 4 ), zirconium oxide (ZrO 2 ), magnesium oxide (MgO), yttrium oxide (Y 2 O 3 ), magnesium fluoride (MgF 2 ), aluminum fluoride (AlF 3 ), zinc sulfide (ZnS), zinc selenide (ZnSe), amorphous silicon, etc., and the thickness range is 20 nm - 2000 nm. By setting the thickness of the multi-layer optical film 300b, optical functions such as high reflection, low reflection, or antireflection for specific wavelengths are achieved.

[0152] Preferably, the multi-layer optical thin film 300b is formed by alternately stacking at least two single-layer optical thin films with different reflectivities, and the thickness l of each single-layer optical thin film m satisfies: l m = λ / 4 / n m ; where λ is the wavelength incident on the semiconductor device, and n m is the refractive index of the corresponding single-layer optical thin film. When depositing the multi-layer optical thin film 300b composed of single-layer optical thin films with different reflectivities, the optical thin film material with a smaller refractive index is preferably deposited first, and the total number of layers of the single-layer optical thin films with different reflectivities deposited should be greater than 5 layers.

[0153] S500, Remove the multi-layer optical thin film on the upper surface of the sacrificial layer in the second region, exposing the upper surface of the sacrificial layer in the second region.

[0154] As Figure 6e shown, all the optical thin films on the upper surface of the sacrificial layer 20 in the second region B can be removed by chemical mechanical polishing or other methods, but the optical thin films on the side surfaces of the sacrificial layer 20 in the second region B are retained, exposing the upper surface of the sacrificial layer 20 in the second region B.

[0155] S600, Remove the sacrificial layer in the second region, exposing the second region of the substrate.

[0156] As Figure 6f shown, the remaining sacrificial layer 20 on the second region B is removed by dry etching or wet corrosion, exposing the second region B of the substrate 10. After the sacrificial layer 20 is removed, a pattern composed of side edges (the optical thin film part formed on the side surface of the sacrificial layer in the second region) and bottom edges (the optical thin film part formed on the surface of the first region) with the height of the optical thin film consistent with the thickness H of the subsequent required epitaxially grown semiconductor epitaxial layer is retained on the substrate 10, forming a mask pattern or a mask pattern array that defines the range of the subsequent required epitaxially grown semiconductor epitaxial layer.

[0157] S700, Form a semiconductor epitaxial layer on the second region of the substrate.

[0158] As Figure 6g shown, epitaxial growth of a compound semiconductor material is carried out on the region of the first surface of the substrate 10 exposed between the mask pattern or the mask pattern array, forming a selectively grown semiconductor epitaxial layer 40. The thickness H of the semiconductor epitaxial layer ranges from 200 nm to 5000 nm. The effective refractive index of the semiconductor epitaxial layer 40 should be greater than 3 and greater than the refractive index n 1 of the optical thin film 300.

[0159] The semiconductor epitaxial layer 40 can include a multi-layer thin film containing an optical gain layer. The thickness t of the optical gain layer1 is from 10 nm to 500 nm. The height h of the center of the optical gain layer from the first surface 10a of the substrate 10 1 is less than the thickness H of the semiconductor epitaxial layer 40.

[0160] The optical gain layer includes low-dimensional quantum structures such as single-layer or multi-layer quantum well layers, single-layer or multi-layer quantum dot layers, and multi-layer superlattice layers. And / or, the optical gain layer includes GaAs / AlGaAs quantum well layers, InAlGaAs / InAlGaAs quantum well layers, InGaAsP / InGaAsP quantum well layers, GaAs / InGaAs quantum dot layers, InAs / GaSb superlattice layers, etc., which have the function of optical absorption or optical gain at specific wavelengths and can be used to form optoelectronic devices such as detectors, lasers, and optical amplifiers.

[0161] S800, remove part of the high-reflection optical thin film layer on part of the side surface of the semiconductor epitaxial layer.

[0162] According to the different reflection functions of the multi-layer optical thin film 300b, control the transmission direction of light. Refer to Figure 6h As shown, by removing part of the high-reflection optical thin film on the light-emitting side of the device, an optical thin film layer 300c with fewer layers than the multi-layer optical thin film 300b on the non-light-emitting side of the device is formed. The number of layers of the optical thin film layer 300c retained on the light-emitting side of the device should be greater than 1 and less than the total number of layers before removal, forming an asymmetric reflection function with the non-light-emitting side of the device to achieve light output from the high-reflection side to the low-reflection side.

[0163] S900, form a stacked waveguide layer and optical cladding layer on the first region of the substrate.

[0164] As Figure 6i shown, alternately deposit non-conductive optical cladding layers 60 and waveguide layers 50 with different refractive indices. Preferably, the waveguide layer 50 is located between two optical cladding layers 60. Among them, the refractive index of the waveguide layer 50 is n w2 , the refractive index of the optical cladding layer 60 is n w1 , and the refractive index of the optical gain layer in the semiconductor epitaxial layer 40 is n g , and the refractive index relationship among the three needs to satisfy 1 < n w1 < n w2 < n g .

[0165] When depositing the optical cladding layer 60 and waveguide layer 50 with different refractive indices, precise alignment of the waveguide layer 50 for optical transmission and the optical gain layer in the semiconductor epitaxial layer 40 is required. Thus, on the light-emitting side of the device, the height h of the center position of the waveguide layer 50 from the first surface 10a of the substrate 10 2should be equal to the height h from the center of the optical gain layer to the first surface 10a of the substrate 10 1 The thickness t of the waveguide layer 50 2 is greater than or equal to the thickness t of the optical gain layer 1 and less than the thickness H of the semiconductor epitaxial layer 40.

[0166] It can be understood that during the deposition of the optical coating layer 60 and the waveguide layer 50, a certain amount of the optical coating layer 60 and the waveguide layer 50 will also be deposited on the upper surface of the semiconductor epitaxial layer 40. Therefore, it is necessary to remove the waveguide layer 50 and the optical coating layer 60 on the upper surface of the semiconductor epitaxial layer 40 to flatten the surface, expose the upper surface of the semiconductor epitaxial layer 40, and facilitate the preparation of subsequent electrodes.

[0167] S1000, forming a first electrode electrically connected to the substrate; and, forming a second electrode electrically connected to the semiconductor epitaxial layer.

[0168] As Figure 6j shown, a second electrode 72 is prepared on the upper surface of the semiconductor epitaxial layer 40 and the second electrode 72 completely covers the upper surface of the semiconductor epitaxial layer 40. The first electrode 71 is led out from the substrate 10 to the surface of the optical coating layer 60. The second electrode and the first electrode are located on the non-light-emitting side. The second electrode and the first electrode are separated and insulated by multiple layers of optical thin films, waveguide layers, and optical coating layers.

[0169] In this third embodiment, a semiconductor device structure is further provided, including:

[0170] A substrate having a first surface and a second surface disposed opposite to each other. The first surface includes a first region and a second region.

[0171] A semiconductor epitaxial layer formed on the second region of the first surface of the substrate. The semiconductor epitaxial layer includes multiple layers of thin films containing an optical gain layer. The optical gain layer includes a single layer or multiple layers of quantum well layers, a single layer or multiple layers of quantum dot layers, and multiple layers of superlattice layers; and / or, the optical gain layer includes GaAs / AlGaAs quantum well layers, InAlGaAs / InAlGaAs quantum well layers, InGaAsP / InGaAsP quantum well layers, GaAs / InGaAs quantum dot layers, InAs / GaSb superlattice layers.

[0172] Multiple layers of optical thin films are formed on the side surface and the first region of the semiconductor epitaxial layer in the second region. Among them, the number of optical thin film layers on the side surface of the semiconductor epitaxial layer on the light-emitting side is less than the number of optical thin film layers on the remaining side surfaces, so that the reflectivity of the light-emitting side of the semiconductor epitaxial layer is lower than that of the other side, realizing single-sided light emission of the device.

[0173] The semiconductor device structure further includes a waveguide layer formed on a multi-layer optical thin film on the first region of the substrate. Also,

[0174] a first electrode and a second electrode, the first electrode being electrically connected to the substrate; the second electrode being electrically connected to the semiconductor epitaxial layer.

[0175] Example 3

[0176] A polyimide layer (sacrificial layer) with a thickness of 4 μm is spin-coated on a 12-inch SOI (001) substrate of an n-type device layer.

[0177] The polyimide layer is fabricated into a mesa with a width of 300 μm (this mesa is the reserved sacrificial layer) by using ultraviolet lithography and reactive ion etching. The angle between the side surface of the mesa and the substrate surface is 90 degrees. The etched area needs to be over-etched to ensure the exposure of the silicon substrate surface.

[0178] Using plasma-enhanced chemical vapor deposition on the patterned polyimide mesa (including the upper surface and the side surface), 6 layers of 224 nm SiO 2 / 171 nm Si 3 N 4 are alternately deposited in sequence to form an optical high-reflection thin film (multi-layer optical thin film) with a total thickness of 1185 nm. The central wavelength of the high reflectivity is 1310 nm. Subsequently, the 1185 nm thick SiO 2 / Si 3 N 4 multi-layer optical thin film on the surface of the polyimide layer is completely removed by chemical mechanical polishing, exposing the upper surface of the polyimide, and the SiO 2 / Si 3 N 4 multi-layer optical thin film on the side surface of the polyimide layer and the SiO 2 / Si 3 N 4 multi-layer optical thin film connected to the SiO 2 / Si 3 N 4 multi-layer optical thin film on the substrate surface are retained.

[0179] All the remaining polyimide layer is completely removed by using N-methylpyrrolidone solvent, and the epitaxial growth mask pattern is formed by the reserved SiO 2 / Si 3 N 4 multi-layer optical thin film.

[0180] After chemically cleaning and drying the silicon substrate with a mask pattern, it is placed into metal-organic chemical vapor deposition, and an n-type InP buffer layer with a total thickness of 4 μm, an InGaAsP optical confinement layer, an InGaAsP / InGaAsP multiple quantum well, an InGaAsP optical confinement layer, a p-type InP cap layer, and a p-type InGaAs contact layer (collectively constituting a semiconductor epitaxial layer) are grown in sequence. The total thickness of the InGaAsP / InGaAsP multiple quantum well is 100 nm, and the center is 2.1 μm away from the first surface of the substrate.

[0181] During epitaxial growth, multiple epitaxial thin films such as InP / InGaAsP / InGaAs are selectively grown on the surface of the silicon substrate without SiO 2 / Si 3 N 4 covered by a multi-layer optical thin film. After growth, the surface of the semiconductor epitaxial layer is flush with the highest point of the SiO 2 / Si 3 N 4 multi-layer optical thin film.

[0182] Using photolithography and chemical etching or dry etching, part of the optical thin film on the light-emitting side of the device is removed, and only two layers of 224 nm SiO 2 / 171 nm Si 3 N 4 with a total of 395 nm of optical thin film are retained. Subsequently, 1705 nm SiO 2 / 400 nm Si 3 N4 / 1700 nm SiO 2 optical cladding layer / waveguide layer / optical cladding layer are deposited in sequence.

[0183] After the waveguide layer and the optical cladding layer are deposited, on the light-emitting side of the device, the waveguide layer and the optical cladding layer are flush with the semiconductor epitaxial layer. Chemical mechanical polishing is used to remove all the waveguide layer and the optical cladding layer on the upper surface of the semiconductor epitaxial layer to make the surface flat and expose the upper surface of the semiconductor epitaxial layer.

[0184] An upper electrode metal (second electrode) is deposited on the upper surface of the semiconductor epitaxial layer, and the upper electrode metal completely covers the upper surface of the semiconductor epitaxial layer. After making a via hole on the non-light-emitting side of the device to expose the surface of the silicon substrate, a lower electrode metal (first electrode) is led out to the surface of the optical cladding layer. Electrical insulation is achieved between the upper electrode metal and the lower electrode metal through the multi-layer optical thin film, waveguide layer, and optical cladding layer on the non-light-emitting side, and the laser device is fabricated.

[0185] After the laser device is fabricated, it operates under the bias voltage of the upper electrode metal and the lower electrode metal. Laser is formed after multiple reflections near the quantum well and exits from the low-reflection side, and enters Si after passing through the optical thin film. 3N 4 Waveguide layer transmission.

[0186] Compared with the prior art, the manufacturing method of the semiconductor device and the semiconductor device structure of the present invention can achieve a large wafer size at a lower substrate cost by fabricating a dielectric film layer or an optical film layer as a mask pattern on a large-size substrate and using the mask pattern for area-selective epitaxial growth of III-V semiconductor materials, and also has the advantages of small device size and high integration degree.

[0187] The manufacturing method of the semiconductor device and the semiconductor device structure of the present invention have a pre-definable mask pattern, can achieve self-passivation immediately after growth, and can effectively prevent the side surfaces of the epitaxial materials exposed outside the selected area from becoming non-radiative recombination centers or side leakage channels of optoelectronic devices in the later stage.

[0188] The manufacturing method of the semiconductor device and the semiconductor device structure of the present invention consist of a multi-layer optical film layer to form a composite optical thin film mask pattern structure, which has an optical function for a specific wavelength, including high reflection, low reflection or anti-reflection functions at a specific optical wavelength. Through the combination of optical film layers with high reflection, low reflection and anti-reflection functions, and combined with the optically gain layer grown epitaxially, optical gain and controllable side emission can be achieved, which is suitable for fabricating devices such as semiconductor lasers and optical amplifiers.

[0189] Different from the conventional semiconductor edge-emitting laser and optical amplifier processes, which require natural cleavage of the epitaxial wafer and then two-side optical coating on the side surfaces respectively, the manufacturing method of the semiconductor device and the semiconductor device structure of the present invention can achieve an optical cavity with high reflection on both sides at the end of epitaxial growth. By adjusting the composite optical thin film mask pattern structure on one side, asymmetrical optical reflection on both sides can be achieved, thereby controlling the light emission direction. In addition, in the light transmission direction, multiple waveguide layers can be deposited and precisely integrated according to the position of the epitaxial optically gain layer, further realizing the multi-material system monolithic photon integration function of lasers, optical amplifiers and optical waveguides.

[0190] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claimed rights.

[0191] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for manufacturing a semiconductor device, characterized in that: include: Providing a substrate, the substrate having a first surface and a second surface arranged opposite to each other, the first surface including a first area and a second area; forming a sacrificial layer on the first surface of the substrate, wherein the sacrificial layer covers the first region and the second region; removing the sacrificial layer in the first region to expose the first region of the substrate; forming a dielectric film or an optical film on the surface of the sacrificial layer in the second region and the first region, wherein the surface of the sacrificial layer in the second region includes an upper surface and a side surface of the sacrificial layer in the second region; removing the dielectric film or the optical film on the upper surface of the sacrificial layer in the second region to expose the upper surface of the sacrificial layer in the second region; removing the sacrificial layer in the second region to expose the second region of the substrate; A semiconductor epitaxial layer is formed on the second region of the substrate.

2. The method for manufacturing a semiconductor device according to claim 1, wherein: The semiconductor epitaxial layer includes a single-layer thin film or a multi-layer thin film including an optical gain layer, wherein a height h1 of the center of the optical gain layer from the first surface of the substrate is less than a thickness H of the semiconductor epitaxial layer.

3. The method for manufacturing a semiconductor device according to claim 2, wherein: The optical gain layer includes a single-layer or multi-layer quantum well layer, a single-layer or multi-layer quantum dot layer and a multi-layer superlattice layer; and / or, The optical gain layer includes a GaAs / AlGaAs quantum well layer, an InAlGaAs / InAlGaAs quantum well layer, an InGaAsP / InGaAsP quantum well layer, a GaAs / InGaAs quantum dot layer, and an InAs / GaSb superlattice layer.

4. The method for manufacturing a semiconductor device according to claim 2, wherein: The optical film is a multilayer optical film, which includes a high-reflection optical film layer and a low-reflection optical film layer. The manufacturing method further includes: After forming a semiconductor epitaxial layer on the second region of the substrate, removing a portion of the high-reflection optical thin film layer on a portion of the side surface of the semiconductor epitaxial layer; and / or, The optical film includes an anti-reflective optical film.

5. The method for manufacturing a semiconductor device according to claim 2, wherein: The production method further comprises: A waveguide layer and an optical cladding layer are stacked and formed on the first region of the substrate.

6. The method for manufacturing a semiconductor device according to claim 5, characterized in that: The height h2 of the center of the waveguide layer from the first surface of the substrate is equal to the height h1 of the center of the optical gain layer from the first surface of the substrate; and / or, The thickness t2 of the waveguide layer is greater than the thickness t1 of the optical gain layer and less than the thickness H of the semiconductor epitaxial layer; and / or, The thickness t1 of the optical gain layer is 10 nm-500 nm.

7. The method for manufacturing a semiconductor device according to claim 5, characterized in that: The refractive index of the waveguide layer is n w2 ; The refractive index n of the optical cladding layer w1 ; The refractive index of the optical gain layer is n g ; Among them, the refractive index relationship satisfies: 1<n w1 <n w2 <n g .

8. The method for manufacturing a semiconductor device according to claim 5, characterized in that: The production method further comprises: forming a first electrode electrically connected to the substrate; and, A second electrode electrically connected to the semiconductor epitaxial layer is formed.

9. The method for manufacturing a semiconductor device according to claim 1, wherein: The angle between the side surface of the sacrificial layer in the second region and the first surface of the substrate is in the range of 80°-100°; and / or The thickness of the sacrificial layer is 200nm-5000nm; and / or, The lateral size of the sacrificial layer in the second region is 1 μm-3000 μm.

10. The method for manufacturing a semiconductor device according to claim 1, wherein: The material of the dielectric film is different from that of the sacrificial layer; and / or, The dielectric film is non-conductive; and / or, The dielectric film includes one of an aluminum oxide film, a silicon oxide film, and a silicon nitride film; and / or, The thickness of the dielectric film is 20nm-2000nm.

11. The method for manufacturing a semiconductor device according to claim 1, wherein: The optical film includes one or more stacked films of aluminum oxide film, titanium oxide film, silicon oxide film, silicon nitride film, zirconium oxide film, magnesium oxide film, yttrium oxide film, magnesium fluoride film, aluminum fluoride film, zinc sulfide film, zinc selenide film and amorphous silicon film.

12. The method for manufacturing a semiconductor device according to claim 1, wherein: The optical film is a single-layer optical film, and the thickness l1 of the single-layer optical film satisfies: l1=λ / 4 / n1; wherein λ is the wavelength incident to the semiconductor device, and n1 is the refractive index of the single-layer optical film.

13. The method for manufacturing a semiconductor device according to claim 1, wherein: The optical film is a multilayer optical film, which is formed by alternately stacking at least two single-layer optical films with different reflectivity, and the thickness of each single-layer optical film is l m Satisfy: m =λ / 4 / n m ; where λ is the wavelength incident to the semiconductor device, n m is the refractive index of the corresponding single-layer optical film.

14. A semiconductor device structure, characterized in that: include: A substrate having a first surface and a second surface arranged opposite to each other, wherein the first surface includes a first area and a second area; a semiconductor epitaxial layer, formed on a second region of the first surface of the substrate; A dielectric film or an optical film is formed on the side surface of the semiconductor epitaxial layer in the second region and on the first region.

15. The semiconductor device structure according to claim 14, characterized in that: Also includes: A first electrode electrically connected to the substrate; The second electrode is electrically connected to the semiconductor epitaxial layer.

16. The semiconductor device structure according to claim 14, characterized in that: The invention also includes a waveguide layer, wherein the waveguide layer is formed on the dielectric film or the optical film on the first area of ​​the substrate.

17. The semiconductor device structure according to claim 16, characterized in that: The height h2 of the center of the waveguide layer from the first surface of the substrate is equal to the height h1 of the center of the optical gain layer from the first surface of the substrate; and / or, The thickness t2 of the waveguide layer is greater than the thickness t1 of the optical gain layer and less than the thickness H of the semiconductor epitaxial layer.

18. The semiconductor device structure according to claim 14, characterized in that: The optical film is a multilayer optical film; The number of optical thin film layers on part of the side surfaces of the semiconductor epitaxial layer in the second region is less than the number of optical thin film layers on the remaining side surfaces of the semiconductor epitaxial layer; and / or, The optical film includes an anti-reflective optical film.

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