CN209561439U - A kind of modified Ge monolithic same layer integrated optoelectronic device of Si base - Google Patents

Abstract

The utility model relates to a kind of modified Ge monolithic same layer integrated optoelectronic devices of Si base, comprising: Si substrate；It is Ge layers intrinsic, it is located on Si substrate；First structure, the second structure, third structure are respectively positioned on intrinsic Ge layer；Wherein, the second structure is between first structure and third structure.The same layer integrated optoelectronic device of the utility model passes through effect of first SiN film to the effect and the second SiN film of waveguide to detector, make waveguide and detector by tensile stress/compression, to have adjusted the forbidden bandwidth of waveguide and detector, so that luminescent device, waveguide and the forbidden bandwidth relationship Eg satisfaction for detecting active layer material: Eg waveguide > Eg light source > Eg detector, to modulate energy band relationship in integrated device, realizes and monolithic light integrated morphology is prepared using same material.

Description

A kind of modified Ge monolithic same layer integrated optoelectronic device of Si base

Technical field

The utility model belongs to technical field of semiconductors, and in particular to a kind of modified Ge monolithic same layer photoelectricity integrator of Si base Part.

Background technique

With the continuous development of optical communication technique and integrated circuit, the miniaturization and low-power consumption of photoelectric signal transformation equipment are asked Topic becomes more more and more urgent.In optical device, electricity device and photoelectricity integration field, silica-base material is current microelectronics industry Main body, have very mature industrial foundation, be the first choice of photoelectricity composite material.However, the optic communication of Si base and photoelectricity are integrated , photoelectric properties good new material mutually compatible with Si technique is developed in the rapidly development an urgent demand of technology.Therefore, Si base extension Ge material comes into being.Theoretically Ge is indirect bandgap material, however it is directly only with indirect belt band gap difference with band gap 136meV, by tensile strain and n-type doping adjust can with so that it becomes quasi- direct band gap material, to improve the direct band of Ge Radiation recombination probability.Based on the characteristic of modified Ge, the modified Ge film of Si base extension has excellent photoelectric properties, and has both The advantage of Si substrate has great application potential in the base extension Ge integrated device field Si.

In the prior art to the integrated technique of luminescent device, waveguide and detector are as follows: utilize different substrate material and different Matter epitaxial material prepares luminescent device, waveguide and detector respectively, then to luminescent device, three parts of waveguide and detector into Row integrates to realize photoelectric conversion；This method and process step is complicated, take a long time and integrated level is lower.And the modified Ge of Si base is thin Film has great advantage using upper luminescent device, waveguide and detector, and the collection of three can be realized in monolithic same layer At simple process and integrated level height.

But although the modified Ge film of Si base has monolithic same layer photoelectricity integrated light-emitting device, waveguide and detector Ability, it is incompatible, each section device active layer material but there are still techniques and structure in integrated device and preparation process Forbidden bandwidth and the inconsistent problem of band structure.

Utility model content

In order to solve the above-mentioned problems in the prior art, it is same that the utility model provides a kind of modified Ge monolithic of Si base Layer integrated optoelectronic device.The technical problems to be solved in the utility model is achieved through the following technical solutions:

The utility model embodiment provides a kind of modified Ge monolithic same layer integrated optoelectronic device of Si base, comprising:

Si substrate；

It is Ge layers intrinsic, it is located on the Si substrate；

First structure is located on the intrinsic Ge layer；Wherein, the first structure and the Si substrate, the intrinsic Ge Light emitting structure is collectively formed in layer；

Second structure is located on the intrinsic Ge layer；Wherein, second structure forms waveguiding structure；

Third structure is located on the intrinsic Ge layer；Wherein, the third structure and the Si substrate, the intrinsic Ge Panel detector structure is collectively formed in layer；

Wherein, second structure is between the first structure and the third structure.

In one embodiment of the utility model, the Si substrate is p-type Si substrate.

In one embodiment of the utility model, the first structure includes:

First p-type Ge body layer is located on the intrinsic Ge layer；

First Ge layers of n-type doping is located on the first p-type Ge body layer；

First Si layers of n-type doping is located on the first n-type doping Ge layer；

First protective layer is located on the first n-type doping Si layer；

Electrode is located on first protective layer and the intrinsic Ge layer.

In one embodiment of the utility model, second structure includes:

Second p-type Ge body layer is located on the intrinsic Ge layer；

First SiN film wraps up the second p-type Ge body layer.

In one embodiment of the utility model, the third structure includes:

Third p-type Ge body layer is located on the intrinsic Ge layer；

Second Ge layers of n-type doping is located on the second p-type Ge body layer；

Second Si layers of n-type doping is located on the second n-type doping Ge layer；

Second protective layer is located on the second n-type doping Si layer；

Second SiN film wraps up the third p-type Ge body layer, Ge layers of second n-type doping, second n-type doping Si layers and the second protective layer, and second SiN film is covered on the intrinsic Ge layer.

In one embodiment of the utility model, electrode is provided on second SiN film.

Compared with prior art, the utility model has the beneficial effects that

1, the utility model covers the first SiN film outside waveguide, covers the second SiN film outside detector, passes through the first SiN Effect of the film to the effect and the second SiN film of waveguide to detector, makes waveguide and detector by tensile stress/compression, thus The forbidden bandwidth of waveguide and detector is had adjusted, so that luminescent device, waveguide and the forbidden bandwidth relationship for detecting active layer material Eg meets: Eg waveguide > Eg light source > Eg detector, to modulate energy band in the modified Ge monolithic same layer integrated optoelectronic device of Si base Relationship realizes and prepares monolithic light integrated morphology using same material.

2, the utility model directlys adopt p-type Si as substrate, avoids making the step of substrate is doped again using Si, tie Structure is simple, and integrated level is high, expands the application range of the modified Ge monolithic same layer integrated optoelectronic device of Si base.

Detailed description of the invention

Fig. 1 is that a kind of structure of the modified Ge monolithic same layer integrated optoelectronic device of Si base provided by the embodiment of the utility model is shown It is intended to；

Fig. 2 is the structure of the modified Ge monolithic same layer integrated optoelectronic device of another kind Si base provided by the embodiment of the utility model Schematic diagram；

Fig. 3 is SiO provided by the embodiment of the utility model₂Transmission analogous diagram of the separation layer under different-thickness；

Fig. 4 a- Fig. 4 c is the schematic shapes of tapered transitional waveguides provided by the embodiment of the utility model；

Fig. 5 is the simulation result diagram of three kinds of tapered transitional waveguides provided by the embodiment of the utility model；

Fig. 6 is what tapered transitional waveguides difference transition length provided by the embodiment of the utility model influenced optical transmission loss Analogous diagram；

Fig. 7 is the collection of the integrated device and no α-Si coating provided by the embodiment of the utility model with α-Si coating At the transmission analogous diagram of device；

Fig. 8 a- Fig. 8 b is the schematic diagram that the first SiN film system adjusts waveguide stress；

Fig. 9 is the schematic diagram that the second SiN film system adjusts detector stress.

Specific embodiment

Further detailed description, but the embodiment party of the utility model are done to the utility model combined with specific embodiments below Formula is without being limited thereto.

Embodiment one

Referring to Figure 1, Fig. 1 is a kind of modified Ge monolithic same layer photoelectricity integrator of Si base provided by the embodiment of the utility model The structural schematic diagram of part, comprising:

Si substrate 001；Intrinsic Ge layer 002 is located on Si substrate 001；First structure 100 is located on intrinsic Ge layer 002； Second structure 200 is located on intrinsic Ge layer 002；Third structure 300 is located on intrinsic Ge layer 002；Wherein, the second structure 200 Between first structure 100 and third structure 300, the second structure 200 is wrapped with the first SiN film 009, third structure 300 The second SiN film 010 is enclosed on outer and intrinsic Ge layer 002.

Specifically, Si substrate 001 with a thickness of 30~750nm, intrinsic Ge layer 002 with a thickness of 40~50nm, the first SiN Film 009 with a thickness of 10~20nm, the second SiN film 010 with a thickness of 10~20nm.

Further, electrode 011 is provided on the second SiN film 010；Further, the material of electrode 011 is preferably gold Belong to Al.

Further, luminescent device, the second structure is collectively formed in first structure 100, Si substrate 001 and intrinsic Ge layer 002 200 form waveguide, and panel detector structure is collectively formed in third structure 300, Si substrate 001, intrinsic Ge layer 002 and electrode 011.

Fig. 2 is referred to, Fig. 2 is that the modified Ge monolithic same layer photoelectricity of another kind Si base provided by the embodiment of the utility model is integrated The structural schematic diagram of device, in Fig. 2, between first structure 100 and the second structure 200, the second structure 200 and third structure 300 Between be provided with SiO₂Separation layer 007, the first SiN film 009 wrap up SiO₂Separation layer 007；Specifically, SiO₂The thickness of separation layer Degree is 20nm, and altitude range is 150~250nm；SiO₂Separation layer is carried out between luminescent device and waveguide, waveguide and detector Isolation, and play the role of certain electric isolution, prevent luminescent device and detector generation ghost effect.

Fig. 3 is referred to, Fig. 3 is SiO provided by the embodiment of the utility model₂Transmission of the separation layer under different-thickness is imitative True figure.As seen from Figure 3, the transmission loss of the longer light of wavelength is by SiO₂The influence of separation layer is smaller；In addition, the SiO of 20nm thickness₂Every Influence of the absciss layer to optical transport is substantially consistent with when not having a separation layer, influences very little, the transmission loss base of light to entire optical transport Originally it can be ignored；Work as SiO₂When separation layer gradually thickeies, transmissivity is gradually reduced, and SiO₂The thicker transmissivity of separation layer But what is reduced is more.It therefore, is not linear relationship between the thickness and transmission of separation layer, but with the increase of thickness, Transmission reduces more.

Above-mentioned conclusion is because of the increase with thickness, SiO₂Scattering loss and reflection all it is increasing cause coupling damage Consumption increases.Wavelength is at 1.75 μm or so, no SiO₂Layer and 20nm thickness SiO₂Coupling efficiency between the device and waveguide of layer is basic It is 84%~85%, and SiO₂Coupling efficiency with a thickness of 50nm thickness is essentially 81%~82%.This illustrates SiO₂To device and wave What the loss influence between leading still be can not ignore.

Further, Si substrate 001 is p-type Si substrate；The utility model embodiment directlys adopt p-type Si as substrate, It avoids making the step of substrate is doped again using Si, structure is simple, and integrated level is high, expands the modified Ge monolithic same layer light of Si base It is electrically integrated the application range of device.

Further, first structure 100 includes the first p-type Ge body layer 013, is located on intrinsic Ge layer 012；First N-shaped Ge layer 014 is adulterated, is located on the first p-type Ge body layer 013；First n-type doping Si layer 015 is located at Ge layers of the first n-type doping On 014；First protective layer 016 is located on the first n-type doping Si layer 015；Electrode 011 is located at the first protective layer 016 and intrinsic On Ge layer 002.

Specifically, the first p-type Ge body layer 013 with a thickness of 150~250nm；The thickness of first n-type doping Ge layer 014 For 100nm, the doping concentration of Ge is 3 × 10¹⁹cm^-3；First n-type doping Si layer 015 with a thickness of 100nm, the doping concentration of Si It is 10²⁰cm^-3；First protective layer 016 with a thickness of 10nm, electrode 011 with a thickness of 10~20nm.

Further, the second structure 200 includes: the second p-type Ge body layer 023, is located on intrinsic Ge layer 002；First SiN Film 009 wraps up the second p-type Ge body layer 003；Further, the second p-type Ge body layer 023 with a thickness of 150~ 200nm, the first SiN film 009 with a thickness of 10~20nm；Further, it refers to Fig. 4 and combines Fig. 2, in the top view of device On, waveguide is that (i.e. shape of the second p-type Ge body layer 003 when to luminescent device and detector transition be tapered transitional waveguides Taper), when from luminescent device to waveguide transition, the tapering width of waveguide；When narrowing down to one fixed width, the width of waveguide is protected It holds constant；In wave guide probe transition, the width of waveguide is gradually expanded.Further, tapered transitional waveguides are concave wave It leads, convex waveguide or linear type waveguide, referring to Fig. 4 a- Fig. 4 c, Fig. 4 a- Fig. 4 c is taper provided by the embodiment of the utility model The schematic shapes of transition waceguide, wherein the tapered transitional waveguides of Fig. 4 a are concave transition waceguide, the tapered transitional waveguides of Fig. 4 b For tapered transition waceguide, the tapered transitional waveguides of Fig. 4 c are linear type transition waceguide；Fig. 5 is referred to, Fig. 5 is that the utility model is real The simulation result diagram that three kinds of tapered transitional waveguides of example offer are provided, it can be seen from the figure that the transmission of convex transition waceguide is most Good, transmission loss is minimum；The transmission of concave transition waceguide is worst, and transmission loss is maximum；Therefore convex transition waceguide is fixed It is advantageous in transition length transmission.

The transition length L of tapered transitional waveguides is the important factor in order for influencing the transmission loss of light, tapered transitional waveguides Transition length L it is longer, variation of the light in the direction of propagation is smaller, but is not linearly increasing；With the increasing of transition length L Add, loss reduction is just fewer and fewer, therefore also just smaller on the influence of the transmission loss of light, refers to Fig. 6, and Fig. 6 is originally practical new The analogous diagram that the tapered transitional waveguides difference transition length that type embodiment provides influences optical transmission loss, wherein transmission is got over Greatly, the transmission loss of light is smaller；By Fig. 6 it can be concluded that, transition length L at 5 μm~15 μm, transmissivity 90% with On, therefore, tapered transitional waveguides length L can choose 5 μm~15 μm；Further, the transition length L of tapered transitional waveguides is At 15 μm, transmission is greater than transmission at 10 μm and 5 μm；However, too long transition waceguide is not that design waveguide is ideal Situation, majority of case require transition waceguide to have certain transition length, it is therefore desirable to further analyze certain transition length The reduction of optical transmission loss in inferior pyramidal transition waceguide designs needs according to practical devices, transition length cannot be too long, therefore L is preferably 10 μm.

In addition, as seen from Figure 6, the wavelength of light is longer, the transmission of device is higher, and the transmission loss of light is with regard to smaller, therefore In the case where practical application allows, longer wavelengths of light is chosen as far as possible.

In order to make up the design of taper coupling height gap, α-Si coating is also covered on the second p-type Ge body layer 023 008；When being covered with α-Si coating 008 on the second p-type Ge body layer 023, the first SiN film 009 wraps up the second p-type Ge main body Layer 003 and α-Si coating 008；Specifically, α-Si coating 008 with a thickness of 0~100nm；Further, α-Si coating It can reduce coupling loss, the case where this is coupled with optical fiber with device is almost the same, and α-Si coating is designed with respect to side wall Loss can more be reduced, therefore it is necessary to add coating.

Fig. 7 is referred to, Fig. 7 is the integrated device provided by the embodiment of the utility model with α-Si coating and no α-Si The transmission analogous diagram of the integrated device of coating.As seen from Figure 7, there is the transmission of α-Si coating integrated device higher than no α- Therefore the transmission of Si coating integrated device it is necessary to add α-Si coating on waveguide.

Further, the first SiN film has compressibility, extension/expansion can occur, so that the first SiN film can become It is finer and close or loose, to make waveguide means/compression, by/change of compression adjust waveguide forbidden band it is wide Spend Eg.

Referring to Fig. 8 a- Fig. 8 b, Fig. 8 a- Fig. 8 b is the schematic diagram that the first SiN film system adjusts waveguide stress.First SiN film System adjusts waveguide stress principle are as follows: the first SiN film 009 acts directly on the second p-type Ge body layer 023 and the α-Si covering of waveguide On layer 008, when the first SiN film becomes densification, dense film makes waveguide by compression T, so that waveguide forbidden bandwidth increases；First When SiN film becomes loose, loose membrane makes waveguide by tensile stress, so that waveguide forbidden bandwidth reduces.

Further, third structure 300 includes: third p-type Ge body layer 033, is located on intrinsic Ge layer 002；Second N-shaped Ge layer 034 is adulterated, is located on third p-type Ge body layer 033；Second n-type doping Si layer 035 is located at Ge layers of the second n-type doping On 034；Second protective layer 036 is located on the second n-type doping Si layer 035；Second SiN film 010 wraps up third p-type Ge body layer 033, the second n-type doping Ge layer 034, the second n-type doping Si layer 035 and the second protective layer 036, and the second SiN film 010 covers On intrinsic Ge layer 002；Further, the second SiN film 010 with a thickness of 10~20nm.The utility model embodiment is using the Two SiN films cover detector, and the second SiN film can make detector receive/compression, to adjust the forbidden bandwidth of detector Eg。

Specifically, third p-type Ge body layer 033 with a thickness of 150~250nm；The thickness of second n-type doping Ge layer 034 For 100nm, the doping concentration of Ge is 3 × 10¹⁹cm^-3；Second n-type doping Si layer 035 with a thickness of 100nm, the doping concentration of Si It is 10²⁰cm^-3；Second protective layer 036 with a thickness of 10nm, electrode 011 with a thickness of 10~20nm.

Fig. 9 is referred to, Fig. 9 is the schematic diagram that the second SiN film system adjusts detector stress.Second SiN film adjusts detector The principle of stress are as follows: due to (being equivalent to the second N-shaped to mix across n-layer among the first SiN film and i layers (being equivalent to intrinsic Ge layer 002) 035) and p layers (being equivalent to third p-type Ge body layer 033), stress cannot directly be made for Si layers of miscellaneous Ge layer 034 and the second n-type doping It uses i layers, but passes through i layers of two sides (no n-layer or p layers of part, i.e., intrinsic Ge layer 002 on cover 010 part of the second SiN film) Apply stress, dense film makes i layers of two sides by compression T, produces so as to cause i layers in detector along the transmission direction perpendicular to light Raw tensile stress, so that detector forbidden bandwidth reduces；Similarly, loose membrane cause in detector i layers along the transmission side perpendicular to light To compression is generated, so that detector forbidden bandwidth increases.

Further, Si substrate 001, intrinsic Ge layer 002, the first p-type Ge body layer 013, the first n-type doping Ge layer 014, Luminescent device, the second p-type Ge body layer 023 is collectively formed in first n-type doping Si layer 015, the first protective layer 016 and electrode 011 Waveguide, Si substrate 001, intrinsic Ge layer 002, third p-type Ge body layer 033, the second N-shaped is collectively formed with α-Si coating 008 Detector is collectively formed in doping Ge layer 034, the second n-type doping Si layer 035, the second protective layer 036 and electrode 011；Luminescent device, Separation layer 007 is provided between waveguide and detector, the covering waveguide of the first SiN film and separation layer 007, the second SiN film are covered on Between detector and electrode 011, and it is covered on the intrinsic Ge layer 002 of detector corresponding part.

The utility model embodiment covers the first SiN film, in explorer portion the second SiN film of covering in waveguide portion, leads to Effect of first SiN film to the effect and the second SiN film of waveguide to detector is crossed, makes waveguide and detector by tensile stress/pressure Stress, so that the forbidden bandwidth of waveguide and detector is had adjusted, so that the forbidden bandwidth relationship of luminescent device, waveguide and detector Eg meets: Eg waveguide > Eg light source > Eg detector, to modulate energy band in the modified Ge monolithic same layer integrated optoelectronic device of Si base Problem realizes and prepares monolithic light integrated morphology using same material.

The working principle of the modified Ge monolithic same layer integrated optoelectronic device of the Si base of the utility model embodiment are as follows: light emitting source The basic structure of LED is a PN junction, and forward bias is minority carrier from the injection of the two sides of knot, therefore near PN junction, There is the nonequilibrium carrier higher than equilibrium concentration, carrier occurs compound；In the recombination process of carrier, along with energy Release；And the direct radiation recombination between semiconductor direct bandgap conduction band bottom and top of valence band accounts for compound leading position, is LED Luminous cardinal principle；For P+N+, due to the collective effect of tensile stress and N-type heavy doping, band structure becomes straight Tape splicing gap, light emitting region are depletion region.

When meeting Eg waveguide > Eg luminous tube > Eg detector, light travels to detector by waveguide region by LED section Part；The basic structure of photodetector is a PIN structural, when the irradiation for receiving incident optical signal, electrons and holes by Transition can occur after excitation, and the energy absorbed determines the position of its transition；In semiconductor, direct band gap and indirect band gap it Between transition can be to corresponding photogenerated current be generated, under applying bias effect, photogenerated current is amplified, to generate detection letter Number；For P+IN+ detector, in depletion region, but since depletion region is relatively narrow, some light may exhaust for transition area It is absorbed other than area, so as to cause quantum efficiency reduction.

It, cannot the above content is specific preferred embodiment further detailed description of the utility model is combined Assert that the specific implementation of the utility model is only limited to these instructions.For the ordinary skill of the utility model technical field For personnel, without departing from the concept of the premise utility, a number of simple deductions or replacements can also be made, should all regard To belong to the protection scope of the utility model.

Claims (6)

1. a kind of modified Ge monolithic same layer integrated optoelectronic device of Si base characterized by comprising

Si substrate (001)；

Ge layers intrinsic (002) is located on the Si substrate (001)；

First structure (100) is located on Ge layers intrinsic (002)；Wherein, the first structure (100) and the Si substrate (001), light emitting structure is collectively formed in intrinsic Ge layers (002)；

Second structure (200) is located on Ge layers intrinsic (002)；Wherein, second structure (200) forms waveguiding structure；

Third structure (300) is located on Ge layers intrinsic (002)；Wherein, the third structure (300) and the Si substrate (001), panel detector structure is collectively formed in intrinsic Ge layers (002)；

Wherein, second structure (200) is between the first structure (100) and the third structure (300).

2. the modified Ge monolithic same layer integrated optoelectronic device of Si base as described in claim 1, which is characterized in that the Si substrate It (001) is p-type Si substrate.

3. the modified Ge monolithic same layer integrated optoelectronic device of Si base as described in claim 1, which is characterized in that the first structure (100) include:

First p-type Ge body layer (013) is located on Ge layers intrinsic (002)；

First Ge layers of n-type doping (014) is located on the first p-type Ge body layer (013)；

First Si layers of n-type doping (015) is located in Ge layers of first n-type doping (014)；

First protective layer (016) is located in Si layers of first n-type doping (015)；

Electrode (011) is located on first protective layer (016) and intrinsic Ge layers (002).

4. the modified Ge monolithic same layer integrated optoelectronic device of Si base as described in claim 1, which is characterized in that second structure (200) include:

Second p-type Ge body layer (023) is located on Ge layers intrinsic (002)；

First SiN film (009) wraps up the second p-type Ge body layer (023).

5. the modified Ge monolithic same layer integrated optoelectronic device of Si base as described in claim 1, which is characterized in that the third structure (300) include:

Third p-type Ge body layer (033) is located on Ge layers intrinsic (002)；

Second Ge layers of n-type doping (034) is located on the third p-type Ge body layer (033)；

Second Si layers of n-type doping (035) is located in Ge layers of second n-type doping (034)；

Second protective layer (036) is located in Si layers of second n-type doping (035)；

Second SiN film (010) wraps up the third p-type Ge body layer (033), Ge layers of second n-type doping (034), described Second Si layers of n-type doping (035) and the second protective layer (036), and second SiN film (010) is covered on the intrinsic Ge On layer (002).

6. the modified Ge monolithic same layer integrated optoelectronic device of Si base as claimed in claim 5, which is characterized in that the 2nd SiN Electrode (011) is provided on film (010).