Summary of the invention
The objective of the invention is to; A kind of double-heterostructure gallium nitride based transistor structure with high electron mobility and manufacture method are provided; This transistor arrangement has high two-dimensional electron gas mobility, can reduce the leakage of channel electrons to both sides, is suitable for developing high-frequency element and circuit; Can improve the puncture voltage and the power output of the device of developing, have technology advantage simple and with low cost simultaneously.
The present invention provides a kind of double-heterostructure gallium nitride based transistor structure with high electron mobility, comprising:
One substrate;
One nucleating layer, this nucleating layer is produced on above the substrate;
One non-ly has a mind to the resistive formation that mixes, and this non-resistive formation of having a mind to mix is produced on above the nucleating layer;
The one non-layer that have a mind to mix inserts, this is non-has a mind to mix and inserts layer and be produced on and non-ly have a mind to mix above the resistive formation;
The one non-high mobility layer of having a mind to mix, this non-high mobility layer of having a mind to mix are produced on non-the doping intentionally and insert above the layer;
One non-ly has a mind to doped aluminum nitride and inserts layer, and this is non-has a mind to doped aluminum nitride and insert layer and be produced on above the high mobility layer, and this is non-, and to have a mind to thickness that doped aluminum nitride inserts layer be 0.3-5nm;
The one non-aluminum gallium nitride barrier layer of having a mind to mix, this non-aluminum gallium nitride barrier layer of having a mind to mix are produced on non-ly has a mind to doped aluminum nitride and inserts above the layer, and this is non-, and have a mind to the to mix thickness of aluminum gallium nitride barrier layer is 10-30nm, and al compsn is between the 0.10-0.35;
One non-ly has a mind to the doped gallium nitride cap, and this is non-has a mind to doped gallium nitride cap and be produced on and non-ly have a mind to mix above the aluminum gallium nitride barrier layer, and this non-thickness of having a mind to the doped gallium nitride cap is 1-10nm.
The present invention also provides a kind of manufacture method of double-heterostructure gallium nitride based transistor structure with high electron mobility, comprises the steps:
Step 1: select a substrate;
Step 2: growth one deck nucleating layer on substrate;
Step 3: growth one deck is non-on nucleating layer has a mind to the resistive formation that mixes;
Step 4: the non-insertion layer of having a mind to mix of growth on the non-resistive formation of having a mind to mix;
Step 5: the non-high mobility layer of having a mind to mix of growth on the non-insertion layer of having a mind to mix;
Step 6: the non-doped aluminum nitride intentionally of growth is inserted layer on the non-high mobility layer of having a mind to mix, and growth thickness is 0.3-5nm;
Step 7: insert the non-aluminum gallium nitride barrier layer of having a mind to mix of growth on the layer in non-doped aluminum nitride intentionally, growth thickness is 10-30nm, and al compsn is between the 0.10-0.35;
Step 8: the non-doped gallium nitride cap intentionally of growth on the non-aluminum gallium nitride barrier layer of having a mind to mix, growth thickness is 1-10nm.
Embodiment
See also shown in Figure 1ly, a kind of double-heterostructure gallium nitride based transistor structure with high electron mobility of the present invention comprises:
One substrate 10;
One nucleating layer 20, this nucleating layer 20 is produced on above the substrate 10, and said nucleating layer 20 is gallium nitride or aluminium nitride or aluminum gallium nitride, and thickness is 0.01-0.50 μ m.
The one non-resistive formation 30 of having a mind to mix, this non-resistive formation 30 of having a mind to mix is produced on above the nucleating layer 20, and the material of the said non-resistive formation 30 of having a mind to mix is Al
yGa
1-yN, 0<y<0.20 wherein, thickness is 1-5 μ m, room temperature resistivity is greater than 1 * 10
6Ω .cm.The effect of this resistive formation 30 has four, and the one, reduce the lattice mismatch between substrate and the epitaxial loayer as resilient coating, improve the crystal mass of epitaxial loayer; The 2nd, reduce element leakage as resistive formation; The 3rd, raise the barrier height of raceway groove as back of the body barrier layer in resilient coating substrate one side, reduce the resilient coating of channel electrons under High-Field and leak, improve the stability of material and device; The 4th, improve the puncture voltage of device, put forward the power output of device.
The one non-layer 40 that have a mind to mix inserts, this is non-has a mind to mix and inserts layer 40 and be produced on and non-ly have a mind to mix above the resistive formation 30, and the said non-material that inserts layer 40 of having a mind to mix is aluminium nitride AlN, and thickness is 0.3-10nm.The effect of inserting layer 40 has two; The one, raise the barrier height of raceway groove in resilient coating substrate one side; Reduce the resilient coating of channel electrons under High-Field and leak, improve the stability of material and device, the 2nd, utilize binary compound that channel electrons and multi-element compounds aluminum gallium nitride resistive formation 30 are separated; Reduce the influence that aluminum gallium nitride resistive formation 30 is introduced channel electron mobility, improve raceway groove two-dimensional electron gas mobility.
The one non-high mobility layer 50 of having a mind to mix, this non-high mobility layer 50 of having a mind to mix are produced on non-the doping intentionally and insert above the layer 40, and said high mobility layer 50 is the non-doped gallium nitride of having a mind to, and thickness is 10-200nm.This high mobility layer 50 provides a good passage for two-dimensional electron gas, has also significantly improved raceway groove two-dimensional electron gas mobility simultaneously.
One non-ly has a mind to doped aluminum nitride and inserts layer 60, and this is non-has a mind to doped aluminum nitride and insert layer 60 and be produced on above the high mobility gallium nitride layer 50, saidly non-ly has a mind to doped aluminum nitride to insert layer 60 thickness be 0.3-5nm.An effect of this aln inserting layer 60 is to utilize binary compound that channel electrons and multi-element compounds aluminum gallium nitride barrier layer (the non-aluminum gallium nitride barrier layer of afterwards chatting 70 of having a mind to mix) are separated, and reduces electron scattering, further improves raceway groove two-dimensional electron gas mobility; The another one effect of aln inserting layer 60 is to utilize the characteristics of its energy gap greater than gallium nitride, effectively limits electronics to non-have a mind to mix aluminum gallium nitride barrier layer 70 and surperficial leakage.
The one non-aluminum gallium nitride barrier layer 70 of having a mind to mix, this non-aluminum gallium nitride barrier layer 70 of having a mind to mix are produced on non-doped aluminum nitride intentionally and insert above the layer 60, and the said non-aluminum gallium nitride barrier layer 70 of having a mind to mix is Al
xGa
1-xN, thickness are 10-30nm, 0.10<x<0.35.This non-aluminum gallium nitride barrier layer 70 of having a mind to mix forms raceway groove raceway groove two dimension electronics by polarity effect.
One non-ly has a mind to doped gallium nitride cap 80, and this is non-has a mind to doped gallium nitride cap 80 and be produced on and non-ly have a mind to mix above the aluminum gallium nitride barrier layer 70, and said non-to have a mind to doped gallium nitride cap 80 thickness be 1-10nm.This non-doped gallium nitride cap 80 intentionally can reduce the device technology difficulty as the cap layer.
Key of the present invention is to adopt on the structure gallium nitride resistive formation in the traditional high electron mobility transistor structure of unique low al compsn aluminum gallium nitride resistive formation 30 replacements; Raise the barrier height of resilient coating substrate one side by the energy gap of aluminum gallium nitride broad, the resilient coating that suppresses channel electrons leaks.Simultaneously; This structure is introduced between high mobility layer 50 and resistive formation 30 and is inserted layer 40; Said insertion layer 40 is an aluminium nitride, and channel electrons and aluminum gallium nitride resistive formation 30 are separated, and reduces the alloy scattering of 30 pairs of channel electrons of aluminum gallium nitride resistive formation; Reduce with the influence of the gallium nitride high resistant resilient coating in aluminum gallium nitride resistive formation 30 replace traditional structural with this, improve the performance of the electron mobility and the device of developing channel electron mobility.
See also Fig. 2 and combine to consult shown in Figure 1, the present invention also provides a kind of manufacture method of double-heterostructure gallium nitride based transistor structure with high electron mobility, comprises the steps:
Step 1: select a substrate 10, described substrate 10 is silicon carbide substrates or Sapphire Substrate or silicon substrate;
Step 2: growth one deck nucleating layer 20 on substrate 10, said nucleating layer 20 is gallium nitride or aluminium nitride or aluminum gallium nitride, thickness is 0.01-0.50 μ m.Described nucleating layer 20 is gallium nitride or aluminium nitride or aluminum gallium nitride, and growth temperature is 500-600 ℃, and growth thickness is 0.01-0.50 μ m, and preferred value is 0.03-0.30 μ m.
Step 3: the non-resistive formation 30 of having a mind to mix of growth one deck on nucleating layer 20, this resistive formation 30 is Al
yGa
1-yN, 0<y<0.20 wherein, growth temperature is 900-1100 ℃, and the preferred value scope is 1020-1100 ℃, and growth thickness is 1-5 μ m, and room temperature resistivity is greater than 1 * 10
6Ω cm, preferred value is greater than 1 * 10
8Ω cm.Described aluminum gallium nitride resistive formation 30 improves the crystal mass of epitaxial loayer on it as resilient coating, and raises the barrier height of channel electrons in resilient coating substrate one side, and the resilient coating that reduces electronics leaks, and improves the stability of material and device.
Step 4: the non-insertion layer 40 of having a mind to mix of growth on the non-resistive formation 30 of having a mind to mix; The described non-insertion layer 40 of having a mind to mix is an aluminium nitride; This layer separates aluminum gallium nitride resistive formation 30 and channel electrons, reduces the alloy scattering of channel electrons, improves channel electron mobility.This layer growth temperature is between 850-1150 ℃, and growth thickness is 0.30-10nm, and preferred value is 1nm.
Step 5: insert the non-high mobility layer 50 of having a mind to mix of growth on the layer 40 non-the doping intentionally, the said non-high mobility layer 50 of having a mind to mix is the non-doped gallium nitride of having a mind to, and thickness is 10-200nm, and growth temperature is between 850-1150 ℃.This layer is the operation raceway groove of two-dimensional electron gas, and the room temperature electron mobility is greater than 500cm2/Vs, and preferred value is greater than 700cm2/Vs.
Step 6: the non-doped aluminum nitride intentionally of growth is inserted layer 60 on the non-high mobility layer 50 of having a mind to mix, and growth temperature is between 850-1150 ℃, and growth thickness is 0.3-5nm, and preferred value is 1nm.Described aln inserting layer 60, this layer can improve the mobility and the surface density of two-dimensional electron gas, improve the combination property of heterogeneous structure material.
Step 7: insert the non-aluminum gallium nitride barrier layer 70 of having a mind to mix of growth on the layer 60 in non-doped aluminum nitride intentionally, growth thickness is 10-30nm, and al compsn is between the 0.10-0.35, and growth temperature is between 850-1150 ℃.
Step 8: the non-doped gallium nitride cap 80 intentionally of growth on the non-aluminum gallium nitride barrier layer 70 of having a mind to mix, growth thickness is 1-10nm, growth temperature is 850-1150 ℃.This layer is the non-doping of having a mind to.
Wherein, the layers of material of growth preferentially adopts the metal-organic chemical vapor deposition equipment method including, but not limited to metal-organic chemical vapor deposition equipment method, molecular beam epitaxy and vapour phase epitaxy on substrate 10.
The invention provides a kind of high electron mobility transistor structure material that is suitable for developing high-frequency element; This structure is raised the barrier height of raceway groove both sides, suppresses electronics leakage to barrier layer surface resilient coating substrate both direction under high field, improves the stability of material and device; Simultaneously through introducing the thin layer that inserts; Channel electrons is separated with ternary compound, reduce alloy scattering, improve electron mobility.Therefore, the present invention can significantly improve the performance of gallium nitrate based high frequency, high-power component and circuit.
First effect of the present invention: this transistor adopts the high resistant aluminum gallium nitride as resilient coating, can suppress channel electrons leakage to the resilient coating direction under high field, is suitable for developing high-frequency element and circuit.
Second effect of the present invention: this transistor adopts the high resistant aluminum gallium nitride as resilient coating, can improve the puncture voltage and the power output of the device of developing.
The 3rd effect of the present invention: even this transistor adopts the high resistant aluminum gallium nitride as resilient coating, owing to the shielding action of thin layer aln inserting layer to alloy scattering, this structure still has high two-dimensional electron gas mobility.
The 4th effect of the present invention: this transistor is all introduced the thin layer aln inserting layer in the both sides of gallium nitride channel layer, reduces the leakage of channel electrons to both sides.
The present invention adopts the aluminum gallium nitride of novel low al compsn as the high resistant resilient coating; This layer one side reduces the lattice mismatch between substrate and the epitaxial loayer as resilient coating; Improve quality of materials, raise potential barrier on the other hand, suppress the leakage of channel electrons to the resilient coating direction; Improve stability of material, in order to development high-frequency element and circuit.
The present invention introduces the thin layer aln inserting layer between aluminum gallium nitride high resistant resilient coating and gallium nitride channel layer; This layer one side further raised barrier height; The resilient coating that reduces electronics greatly leaks; Can channel electrons and aluminum gallium nitride high resistant resilient coating be separated on the other hand, reduce the alloy scattering of electronics, improve channel electron mobility.
The present invention can obtain to be suitable for the high electron mobility transistor structure material of high frequency millimetric wave device and circuit development; This material is introduced wideer thin layer aln inserting layer and the aluminum gallium nitride high resistant resilient coating in forbidden band in substrate one side of channel layer; The resilient coating that reduces channel electrons leaks, and improves the confinement characteristic of electronics.
The present invention can obtain the more heterogeneous structure material of high electron mobility; This material is introduced the thin layer aln inserting layer between aluminum gallium nitride high resistant resilient coating and gallium nitride channel layer; Channel electrons and aluminum gallium nitride resilient coating are separated, reduce alloy scattering, improve channel electron mobility.
Above-described specific embodiment; Be that the object of the invention, technical scheme and beneficial effect have been carried out further explain; All within spirit of the present invention and principle, any modification of being made, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.