Electronic devices with impurity gettering and method for operating or producing light-emitting diode

Abstract

In a typical embodiment, an electronic device includes: a semiconductor structure comprising a doped surface; a silver-based (Ag-based) layer electrically contacting at least a portion of the doped surface; and a passivation layer disposed on a portion of the semiconductor structure. A portion of the passivation layer is in contact with the Ag-based substrate. The passivation layer comprises a compound of a group II nitride material.

Description

Electronic device with impurity removal function This invention relates to electronic devices and related methods. For example, this invention relates to semiconductor devices, such as miniature light-emitting diode (micro-LED) devices and related methods. The manufacture of semiconductor devices can involve a series of complex processes (operations, etc.). These processes may include thermal processes, chemical processes, etching processes, material deposition operations, material growth processes, implantation processes, etc. In some examples, an element or portion of a semiconductor device produced during a process may be adversely affected by a series of processes. For example, a light-emitting diode (LED) (such as a microLED) produced using a semiconductor manufacturing process may include metal contacts that provide both electrical connectivity for the operation of an associated LED and reflectivity for light emitted by the LED (e.g., for optical operation of the LED). These contacts may be adversely affected (e.g., degraded) by semiconductor processes performed after the associated processes used to produce the contacts. For example, such subsequent manufacturing processes may degrade electrical performance (e.g., stability) and / or optical performance (e.g., reflectivity) due to degradation of a contact (contact layer, reflective contact, etc.). In a typical configuration, an electronic device includes: a semiconductor structure comprising a doped surface; a silver-based (Ag-based) layer electrically contacting at least a portion of the doped surface; and a passivation layer disposed on a portion of the semiconductor structure. A portion of the passivation layer is in contact with the Ag-based substrate. The passivation layer comprises a compound of a group II nitride material. The implementation scheme may include one or more of the following features or states, individually or in combination. For example, the doped surface may be at least one of the top surface of the semiconductor structure or the surface of an epitaxial layer. The semiconductor structure may include a sidewall surface. At least a portion of the passivation layer may be disposed on the sidewall surface. A first portion of the Ag substrate may be disposed on the doped surface. A second portion of the Ag substrate may be disposed on the passivation layer. The electronic device may have a lateral dimension of less than or equal to 10 micrometers (µm). The semiconductor structure may contain a group III nitride material. The group II nitride material may contain at least one of magnesium nitride, calcium nitride, or beryllium nitride. The material compound may contain Group III elements. The passivation layer may contain at least 90 percent of the group II nitride material based on the composition. The semiconductor structure may include a layer containing gallium nitride (GaN) and a light-emitting layer containing indium gallium nitride (InGaN). The electronic device may be a light-emitting diode (LED). The LED may include a platform having a top surface, a sidewall, and a substrate. The passivation layer may cover a portion of the top surface and a portion of the sidewall. For light having a wavelength in the range of 450 to 650 nanometers (nm), the interface between the Ag substrate and the doped surface can have a reflectivity of more than 90 percent. For light having a wavelength in the range of 450 to 650 nanometers (nm), the passivation layer may have a refractive index greater than 1.7. The passivation layer can be configured to absorb at least one of oxygen or hydrogen. The passivation layer can be configured to trap mobile charges. In another general example, a micro light-emitting diode (microLED) includes: a semiconductor structure having a doped surface; and a light-emitting region. The microLED also includes: a metal substrate electrically contacting at least a portion of the doped surface; and a passivation layer disposed on the semiconductor structure. A portion of the passivation layer is in solid contact with the metal substrate. The passivation layer is a compound comprising a group II nitride material. The microLED has a lateral dimension of less than or equal to 10 micrometers (µm). The implementation scheme may include one or more of the following features or states, individually or in combination. For example, the metal substrate may be an Ag substrate. A first portion of the Ag substrate may be disposed on the doped surface. A second portion of the Ag substrate may be disposed on the passivation layer. The semiconductor structure may contain a group III nitride material. The group II nitride material may contain at least one of magnesium nitride, calcium nitride, or beryllium nitride. The compound may further contain a group III element. The passivation layer may contain at least 90 percent of the group II nitride material based on the composition. The semiconductor structure may include a layer containing gallium nitride (GaN) and a light-emitting layer containing indium gallium nitride. For light having a wavelength in the range of 450 to 650 nm, the interface between the metal substrate and the doped surface may have a reflectivity greater than 90 percent. For light having a wavelength in the range of 450 to 650 nm, the passivation layer may have a refractive index higher than 1.7. The passivation layer can be configured to absorb at least one of oxygen or hydrogen. The passivation layer can be configured to trap mobile charges. In another general embodiment, an LED comprises: a semiconductor structure having a doped surface and a light-emitting region; a silver-based (Ag-based) layer electrically contacting at least a portion of the doped surface; and a passivation layer formed on a surface of the semiconductor structure. A portion of the passivation layer is in contact with the Ag-based substrate. The passivation layer comprises a chemical element X having an enthalpy of formation of oxide XO greater than 500 kJ / mol. The implementation may include one or more of the following features or states, individually or in combination. For example, the passivation layer may contain a compound of X and nitrogen. A first portion of the Ag substrate may be disposed on the doped surface. A second portion of the Ag substrate may be disposed on the passivation layer. The LED may have a lateral dimension of less than or equal to 10 µm. The semiconductor structure may contain a group III nitride material. X can be a group III element. The passivation layer may contain a group III element. The passivation layer may contain at least 10 percent X based on the composition. The semiconductor structure may include a layer containing gallium nitride (GaN) and a light-emitting layer containing indium gallium nitride (InGaN). For light having a wavelength in the range of 450 to 650 nm, the interface between the Ag substrate and the doped surface can have a reflectivity greater than 90 percent. For light with a wavelength in the range of 450 to 650 nanometers (nm), the passivation layer has a refractive index greater than 1.7. The passivation layer can be configured to absorb at least one of oxygen or hydrogen. The passivation layer can be configured to trap mobile charges. In another general example, a method for generating a light-emitting diode (LED) includes forming a silver-based (Ag-based) layer on a doped surface of a semiconductor structure comprising a light-emitting region. The Ag-based layer is electrically contacted on the doped surface. The method also includes forming a dielectric layer on the semiconductor structure. The dielectric layer is adjacent to the Ag-based layer. After forming the Ag-based layer and the dielectric layer, the method includes performing a thermal processing operation on the semiconductor structure, wherein the dielectric layer is configured to maintain a reflectivity of the Ag-based layer greater than or equal to 80% for light at a wavelength of 500 nm after the thermal processing operation. The implementation scheme may include one or more of the following features or states, individually or in combination. For example, the dielectric layer may comprise a group II nitride material. The dielectric layer may contain a chemical element X, which is an oxide XO with a formation enthalpy greater than 500 kJ / moles. The heat treatment operation may be performed at least in part at a temperature greater than or equal to 300°C. The heat treatment operation may be one of the following: an annealing operation, a semiconductor doping activation operation, a metal reflow operation, or a metal bonding operation for the Ag substrate. Maintaining this reflectivity may involve the dielectric layer absorbing at least one of hydrogen or oxygen during the heat treatment operation. This dielectric layer can trap mobile charges. Forming the dielectric layer may include forming the dielectric layer such that at least a portion of the dielectric layer is in contact with the Ag substrate. A chemical species may be present during this heat treatment operation. The dielectric layer can absorb the chemical species. The chemical species may be either oxygen or hydrogen. In another general example, for a light-emitting diode (LED), an operating method includes operating the LED with an electric current such that a light-emitting region of the LED emits light. The LED has: a semiconductor structure having a doped surface and a light-emitting region; a silver-based (Ag-based) layer electrically contacting at least a portion of the doped surface; and a dielectric passivation layer comprising a group II nitride material formed on a surface of the semiconductor structure, wherein a portion of the dielectric passivation layer is in contact with the Ag-based substrate. The dielectric passivation layer is configured to promote stable operation of the LED during the operation. The implementation scheme may include one or more of the following features or states, individually or in combination. For example, facilitating stable operation of the LED may include trapping mobile charges in the dielectric passivation layer. The stable operation of this LED can be characterized by its substantially constant light output over time. Stable operation of this LED can be characterized by the hysteresis of its current-voltage characteristic being below a threshold value. This threshold value can be 50 millivolts at the LED's operating current. This operating current corresponds to a current density greater than 1 ampere per square centimeter in the light-emitting region. The LED can have a lateral dimension of less than 10 micrometers. For light of a wavelength of 500 nanometers emitted from the luminescent region, the Ag substrate may have a reflectivity of greater than or equal to 90%. In another general example, a method for generating a light-emitting diode (LED) includes: forming a semiconductor LED platform; forming a protective layer on the semiconductor LED platform; forming a metal contact on the semiconductor LED platform; and performing a processing operation on the LED. The processing operation causes the release of a species. The protective layer is configured to reduce the diffusion of the species toward the semiconductor LED platform. The implementation scheme may include one or more of the following characteristics or states, alone or in combination. For example, the species may be oxygen or hydrogen. The semiconductor LED platform may have a sidewall, and the protective layer may cover a portion of the sidewall. This protective layer can absorb the species. The protective layer may contain one of the chemical elements X that reacts with the species to form either oxide XO or hydride XH. This protective layer can be used as a diffusion barrier for one of the species. The protective layer may have a thickness of at least 5 nm. This protective layer can trap mobile charges. This metal contact can be an Ag-based contact. The protective layer can be in direct contact with the Ag base junction and can cause the Ag base junction to maintain a high reflectivity during the processing operation. This protective layer can reduce the spread of the species toward the Ag base junction. In another general example, a light-emitting diode (LED) includes: a semiconductor platform having an n-type doped region; an active region; and a p-type doped region terminated by a p-type surface. The LED also includes a p-type contact disposed on a portion of the p-type surface. The p-type contact includes: an Ag substrate electrically contacting the p-type surface; and a metal stack encapsulating the Ag substrate. The metal stack includes at least one layer of a conductive compound containing a metal and nitrogen. The implementation scheme may include one or more of the following features or states, alone or in combination. For example, the conductive compound may act as a diffusion barrier for hydrogen. The metal may contain one of titanium, magnesium, cobalt, tantalum or tungsten. The conductive compound may contain one of titanium nitride, magnesium nitride, cobalt nitride, tantalum nitride, or tungsten nitride. This conductive compound can have a conductivity less than 1e. -3 ohm.cm is one of the resistivity values. The at least one layer of the conductive compound may have less than 10 5 One of the resistors in the ohm series. The metal stack may include a first metal disposed between the Ag substrate and the conductive compound, and a second metal disposed on the conductive compound opposite to the Ag substrate. The Ag base layer can be in direct contact with the p-type surface. A transparent oxide can be placed between the Ag substrate and the p-type surface. The LED may have a first hydrogen concentration in the Ag substrate and a second hydrogen concentration on the side of the at least one layer of the conductive compound opposite to the Ag substrate. The second hydrogen concentration may be at least ten times the first hydrogen concentration. In another general example, a light-emitting diode (LED) includes a semiconductor platform having: an n-type doped region; a light-emitting region; a p-type doped region terminated by a p-type surface; and at least one sidewall. The LED also includes a p-type contact formed on a portion of the p-type surface. The p-type contact includes at least one layer of a conductive compound containing a first metal and nitrogen. The LED further includes a passivation layer formed on a portion of the at least one sidewall. The passivation layer includes at least one layer of an insulating compound containing a second metal and nitrogen. The implementation scheme may include one or more of the following features or states, alone or in combination. For example, the conductive compound may act as a diffusion barrier for hydrogen. The first metal may include one of titanium, magnesium, cobalt, tantalum or tungsten. The conductive compound may contain one of titanium nitride, magnesium nitride, cobalt nitride, tantalum nitride, or tungsten nitride. This conductive compound can have a conductivity less than 1e. -3 ohm.cm is one of the resistivity values. The at least one layer of the conductive compound has a density of less than 10. 5 One of the resistors in the ohm series. The LED may include a third metal disposed between the p-type contact and the conductive compound, and a fourth metal disposed on the conductive compound opposite to the p-type contact. The second metal may include one of magnesium, calcium, or beryllium. The insulating compound may contain one of magnesium nitride, calcium nitride, or beryllium nitride. In another general example, a method for producing an LED includes: forming a p-type contact in direct contact with a p-type surface of an LED semiconductor platform; and forming a metal stack on the p-type contact, wherein the metal stack has a conductive barrier layer. The method also includes performing a processing operation on the LED. This processing operation uses or causes the release of hydrogen. The conductive barrier layer is configured to reduce the diffusion of hydrogen through the p-type contact to the p-type surface during the processing operation. The implementation scheme may include one or more of the following features or states, individually or in combination. For example, the p-type contact may be Ag-based. The conductive barrier layer can be configured such that the hydrogen flow rate to one of the p-type surfaces is less than 10 during the processing operation. 13 cm -2 . The conductive barrier layer can be configured such that, due to the diffusion of hydrogen during the processing operation, the additional hydrogen concentration near the p-type surface after the processing operation is less than 10. 19 cm -3 . This processing operation may involve depositing silicon oxide using a TEOS precursor. This processing operation can be performed at a temperature above 300ºC. The p-type contact can have less than 1e after this processing operation. -4 ohm cm 2 One of the specific contact resistances. This invention relates to electronic devices, such as semiconductor devices, which include a conductive and optically reflective contact. For example, embodiments described herein include light-emitting diodes (LEDs), such as microLEDs, for example, LEDs having a lateral dimension of 10 micrometers (µm) or less. In some embodiments, a microLED includes a semiconductor structure (semiconductor component, semiconductor stack, etc.), an Ag-based contact, and a dielectric passivation layer (dielectric layer, protective layer, etc.) and other elements. In some embodiments, the semiconductor structure includes an n-type doped region, a p-type doped region, and an active light-emitting region (an active region, a light-emitting region, an active quantum well (QW) region, etc.). In some embodiments, the conductive and optically reflective contact may include a silver-based (Ag-based) contact providing electrical contact to the p-type doped region of the semiconductor structure, the Ag-based contact having a low contact resistance and a high optical reflectivity for light emitted from the active region. In some embodiments, the passivation layer may be used for one or more purposes. For example, in some embodiments, the passivation layer may reduce nonradiative recombination (non-luminescent carrier recombination) at the surface of the LED. In some embodiments, the passivation layer may trap mobile charges, thus promoting stable electrical operation of the LED (e.g., no hysteresis, or significantly reducing hysteresis below a threshold value). In some embodiments, the passivation layer may remove oxygen (O) and / or hydrogen (H) (or other chemical species). For example, oxygen removal may help prevent oxidation of the Ag-based contact (which may increase contact resistance and / or reduce reflectivity). Oxygen removal may help prevent passivation of the p-type doped region (which may increase contact resistance). In some implementations, the passivation layer (e.g., an adsorption passivation layer) may have a low oxygen content or concentration, as described herein. Figure 1 is a schematic diagram illustrating one example of a microLED 100 (e.g., a cross-sectional view of the microLED 100). As shown in Figure 1, the microLED 100 includes a buffer layer 110 (e.g., a gallium nitride (GaN) buffer layer) having a growth interface surface 115 for, for example, epitaxial growth of a microLED platform 120. As shown in Figure 1, the microLED platform 120 is formed on the growth interface surface 115. In some embodiments, the formation of the microLED platform 120 may be achieved by selective region epitaxial growth, planar epitaxial growth and etch-back, subsequent regrowth steps and / or other procedures. As shown in Figure 1, the microLED platform 120 of the microLED 100 includes at least one n-type doped layer 122, an active region 124 (active QW region), and at least one p-type doped layer 126. In this example, the microLED platform 120 has inclined or ramped sidewalls. In some embodiments, a microLED may have vertical and / or other shaped sidewalls. In some implementations, the micro-LED platform 120 has a p-type doped top surface 128 (e.g., in the configuration shown in Figure 1). As shown in Figure 1, the microLED 100 includes an Ag-based contact 130. In this example, the Ag-based contact 130 is formed on a portion of a p-type doped top surface 128. The microLED 100 also includes a passivation layer 140 disposed on a portion of the microLED platform 120 adjacent to the Ag-based contact 130 (e.g., adjacent to the Ag-based contact 130, in contact with the Ag-based contact 130, etc.). In some embodiments, such as in the microLED 100, the passivation layer 140 may be formed on at least a portion of the p-type doped top surface 128 and / or at least a portion of the sidewalls of the microLED platform 120. In some embodiments (such as those described herein), the passivation layer 140 may improve the optical performance of the microLED 100, for example, by removing impurities during semiconductor processing, and / or, for example, by passivating electrical traps, improve the electrical operational stability of the microLED 100. The microLED 100 also includes a reflector 132 disposed on a portion of the microLED 100. In this example, the reflector 132 is disposed on a portion of the passivation layer 140 on the sidewall of the microLED platform 120. In the microLED 100, the reflector 132 is electrically isolated from the Ag base contact 130. In some embodiments, a reflector (such as reflector 132) may be (electrically and / or physically) connected to the Ag base contact 130. The reflector 132 may be a high-reflectivity layer, such as an Ag base mirror. In some embodiments, passivation layer 140 may have one or more of the following characteristics or properties. In some embodiments, passivation layer 140 may be a dielectric layer comprising a material composition of nitrogen (N) and an element X, wherein X is an element having a high enthalpy for forming oxides and / or low solubility with other elements. For example, X may have an enthalpy greater than 500 kJ / moles for forming oxide XO. In some embodiments, passivation layer 140 may be substantially a nitride-based dielectric (such as SiN). In some embodiments, passivation layer 140 may be a dielectric layer combining a group II element and nitrogen (N), for example, a group II nitride material. In some embodiments, the group II element may be one of magnesium (M), calcium (Ca), or beryllium (Be). In some embodiments, passivation layer 140 may be at least ninety percent (90%) of a group II nitride material based on the composition. In some embodiments, X may alternatively form a hydride XH. In some embodiments, the passivation layer 140 may be a compound containing one of a Group II element, nitrogen, and at least one additional element. The additional element may include a Group III element, such as boron (B), aluminum (Al), gallium (Ga), or indium (In). In some embodiments, the passivation layer 140 may be a dielectric layer containing or including magnesium or magnesium nitride, such as Mg. 2N 3 (Although other ideal proportions or deviations from this precise ideal proportion are possible), such as materials containing, for example, Ca or CaN, or materials containing, for example, Be or BN. In some embodiments, the passivation layer 140 may have a very low concentration of oxygen (e.g., less than 1e15 cm⁻¹). -3 Less than 1e14 cm -3 Less than 1e13 cm -3 Less than 1e12 cm -3 Less than 1e11 cm -3 or less than 1e10 cm -3 In some implementations, the passivation layer 140 may contain carbon (C). In some embodiments, the passivation layer 140 may comprise a dielectric material that comprises or contains at least two of Mg, Ca, Be, N, C, or O. In some embodiments, the material of the passivation layer 140 may comprise or contain a macroscopic amount of certain elements. For example, in some embodiments, at least 1% (at least 5%, at least 10%, or at least 20%) of the atomic composition may be Mg, Ca, or Be, and at least 1% (at least 5%, at least 10%, or at least 20%) of the atomic composition may be at least one of N, C, or O. In some embodiments, at least 10% of the atomic composition of the passivation layer 140 is Mg, Ca, or Be, and at least 10% is N. In some instances, the material of the passivation layer 140 (or a portion thereof) is substantially made of (or solely of) a Group II nitride material. In some embodiments, the atomic composition of any other element is less than 1% (less than 0.1%, less than 0.01%, less than 0.001%, or less than 0.0001%). In some instances, the density of any other element (other than the Group II nitride material) as measured by SIMS is less than 1e20 cm⁻¹. -3 (less than 1e19 cm) -3 Less than 1e18 cm -3 Less than 1e17 cm -3 Less than 1e16 cm -3 or less than 1e15 cm -3 ). The passivation layer 140 may have at least one of the following properties. In some instances, the passivation layer 140 serves as an oxygen removal layer and / or a hydrogen removal layer. In some embodiments, oxygen and / or hydrogen may originate from various sources within the structure of the microLED 100 and / or from processing operations used to generate the microLED 100. Oxygen and / or hydrogen may move (e.g., by diffusion, migration, etc.) across or through the structure of the microLED 100. In some embodiments, the migration of oxygen and / or hydrogen toward or to a reflective layer (such as an Ag substrate) may be detrimental to its reflectivity and / or its contact resistance. Therefore, in some embodiments, the passivation layer 140 may remove oxygen and / or hydrogen, thereby reducing their diffusion toward the Ag base junction 130. In some embodiments, this may result in a metal layer with high reflectivity and may also improve the operational stability and performance of an associated device (e.g., the microLED 100). In some embodiments, a metal layer (contact layer) used in a device (e.g., a micro LED 100) may be substantially Ag-based, for example, an Ag-based contact 130. In some instances, this metal layer has a reflectivity greater than 90% (greater than 95%, or greater than 97%). The reflectivity may be within a wavelength in the visible range of 400 to 700 nm, for example, in the range of 450 to 650 nm, at 500 nm, etc. In some instances, the metal layer may be a reflective metal stack having a reflectivity of at least 80% (at least 85%, at least 90%, or at least 95%). In some embodiments, the passivation layer 140 may serve as both an impurity removal layer and a charge trap. As used herein, an impurity is an element (e.g., oxygen and / or hydrogen) that can propagate (diffusion, migration, etc.) through a structure and impair (e.g., damage, degradation, etc.) the reflectivity of a metal layer (such as Ag-based contact 130) and / or increase the resistance of a contact formed using the metal layer (Ag-based contact 130). Figure 2 is a diagram illustrating the impurity removal function of a passivation layer 240 in an electronic device 200, such as for an impurity 205. The electronic device 200 may be a micro-LED or other device. Similar to the view of the micro-LED 100 in Figure 1, the view of the electronic device 200 in Figure 2 is a cross-sectional view. In this example, the electronic device 200 includes a semiconductor structure 220 (e.g., a semiconductor component, a semiconductor stack, etc., which may be doped, e.g., n-type or p-type doped), an Ag base contact 230, a metal stack 235, and a passivation layer 240, which may be a passivation layer as described herein. As shown in Figure 2, the metal stack 235 may be disposed on the Ag base contact 230 and the passivation layer 240, wherein the passivation layer 240 is close to (e.g., adjacent to and / or in contact with) the Ag base contact 230. In some embodiments, impurity 205 may originate from semiconductor structure 220, from metal in metal stack 235, and / or from other layers in electronic device 200. In some embodiments, impurity 205 may also originate from the surrounding environment during a processing operation (e.g., from a liquid or gas used during processing). In some embodiments, impurity 205 may propagate through electronic device 200. This migration may be attributed to, for example, diffusion. In some embodiments, the propagation of impurity 205 may be facilitated by properties of a processing operation and / or the operation of electronic device 200 (such as a high-temperature processing operation (e.g., above 300°C), the application of a bias voltage, etc.). In some embodiments, impurity 205 may adversely affect the reflectivity of one of the Ag-based contacts 230 and / or passivate semiconductor structure 220 at an interface with Ag-based contacts 230, thereby causing an increase in the resistance of one of the associated contacts of semiconductor structure 220. In some embodiments, such as the example in FIG2, the passivation layer 240 adsorbs impurities, thereby causing their capture and / or preventing them from damaging (e.g., destroying) the reflectivity of the Ag-based contact 230 and / or preventing an increase in associated contact resistance. In some embodiments, once the impurity 205 is adsorbed, it can be stabilized within the passivation layer 240. For example, the impurity can remain within the passivation layer 240 during further processing and / or use of the electronic device 200 (e.g., high-temperature operation, device operation, etc.). In some embodiments, this stability can be provided, for example, by forming chemical bonds between the impurity 205 and the passivation layer 240 and / or by trapping the impurity 205 within the passivation layer 240. Figure 3 is one of the experimental results, Graph 300, which demonstrates that an absorbent passivation layer (e.g., passivation layer 140, passivation layer 240, etc.) can improve the stability and / or optical performance of an Ag-based contact. In Graph 300, trace 350 illustrates the experimental results of a microLED with an absorbent passivation layer, while trace 360 ​​illustrates the experimental results of a previous device without an absorbent passivation layer. In both examples in Graph 300, the microLED includes an Ag-based contact and is approximately 2 µm (in lateral diameter). The experimental results illustrated in Figure 3 are collected by operating each microLED with an electric current, causing one of the light-emitting regions of the LED to emit light. For the microLED device corresponding to trace 350, during operation, the dielectric passivation layer promotes stable operation of the LED as described herein. Figure 300 shows the relative (normalized) external quantum efficiency (EQE) of the devices corresponding to traces 350 and 360. As can be seen in Figure 3, comparing traces 360 and 350, the microLED device without a passivation layer (trace 360) has a severely suppressed EQE caused by the degradation of the Ag base contact due to impurities during device fabrication and / or by additional diffusion of impurities during operation. In contrast, the microLED including a passivation layer (trace 350) has a relatively high EQE promoted by a high-reflectivity Ag base contact and, for example, by the low associated contact resistance due to the passivation action of the passivation layer. In some implementations, although the experimental results in Figure 3 are discussed for microLEDs with Ag-based contacts, such improvements in stability and optical performance can also occur for metal contacts that do not contain Ag or contain Ag (e.g., to a p-type doped layer of an LED platform) (such as for platinum (Pt)-based or Ni-based contacts and / or contacts containing other metals or materials). As mentioned above, in some embodiments, a passivation layer may include or contain a chemical element X having a high enthalpy (absolute value) for forming an oxide layer (e.g., in the form of XO). In some embodiments, the enthalpy may be at least 500 kJ / mol. By way of example, Table 1 below shows the enthalpy (denoted as DHr, and having a negative value) for forming some oxides. Table 1: In some embodiments, in addition to impurity removal, a passivation layer (such as the passivation layer described herein) can also reduce non-radiative recombination. For example, when formed above a surface of a semiconductor structure of an LED platform (e.g., a micro-LED platform), an exemplary passivation layer can passivate dangling bonds. In some embodiments, the surface can be characterized by a recombination rate of less than 1e5 cm / s (less than 1e4 cm / s, less than 1e3 cm / s, less than 1e2 cm / s, or less than 1e1 cm / s). In some embodiments, a passivation layer (such as the passivation layer described herein) can reduce the recombination rate by at least 10-fold compared to previous embodiments. Passivation layers (such as those described herein) and corresponding electronic devices (e.g., semiconductor devices, LEDs, micro-LEDs, etc.) may have one or more of the following properties. For example, in some instances, a passivation layer has a refractive index in the range of 2.3 to 2.7. In some instances, the passivation layer has a refractive index within + / - 0.1 (+ / - 0.2, + / - 0.3, or + / - 0.5) of the refractive index of GaN. In some instances, a passivation layer has a refractive index greater than 1.7 (greater than 1.8, greater than 1.9, or greater than 2). A passivation layer can be a stack of multiple materials. In some embodiments, this stack may include materials such as those described herein, as well as other materials such as silicon oxide (SiO2). x ), silicon nitride (SiN) x ), aluminum oxide (AlO) x A combination of one of (and / or other materials). An apparatus may have a passivation layer (a first layer) rich in Group II atoms (e.g., a composition containing or including at least 10% atomic groups of Mg, Ca, Be, or other Group II elements) and a second layer overlying the first layer, wherein the second layer maintains the stability (e.g., chemical and / or mechanical stability) of the Group II-rich layer. In some embodiments, the second layer may completely encapsulate the first layer. In some embodiments, the second layer may, for example, prevent the first layer from contacting air, other gases (e.g., gases containing or including O and C) and / or fluids during a processing operation or during operation of the apparatus. In some embodiments, a metal contact may be Ag-based, as shown in Figures 1 and 2 (e.g., Ag-based contact 130 or Ag-based contact 230, respectively). In some embodiments, this may include contacts having various stacking configurations in which silver is a major element (e.g., a bulk stack having at least 99% (at least 99.9%, or at least 99.99%) Ag). In some embodiments, a metal contact may comprise or be a multilayer stack, wherein a bulk Ag layer alternates with other metals (such as nickel (Ni), platinum (Pt), aluminum (Al), titanium (Ti), palladium (Pd), etc.) and / or transparent oxides (e.g., indium tin oxide (ITO), tin oxide (ZnO), etc.). In some embodiments, a metal contact may comprise a thin layer of a metal (e.g., less than 5 nm, less than 1 nm, or less than 0.5 nm), or may be stacked with such a thin layer at an interface with a semiconductor structure, wherein the thin layer is covered by a bulk Ag layer or an Ag substrate. Figures 4A through 4F are schematic diagrams (e.g., cross-sectional views) illustrating exemplary configurations of Ag-based contacts. As used herein, an Ag-based contact is one in which silver substantially contributes to a high reflectivity. Although not specifically shown in Figures 4A through 4F, the illustrated exemplary contacts can be disposed on a current-voltage semiconductor structure (such as an LED platform of a microLED) (e.g., forming an ohmic contact interface with the current-voltage semiconductor structure). Figure 4A illustrates a pure Ag contact 430a, in which a passivation material 440a is in direct contact with the pure Ag contact 430a. Figure 4B illustrates an Ag-based contact 430b covered by a metal stack 435b. As shown in Figure 4B, a passivation layer 440b lies beneath at least a portion of the metal stack 435b and is in contact with the Ag-based contact 430b. In this example, the metal stack 435b can improve adhesion (e.g., so that one layer of the metal stack 435b is in direct contact with the pure Ag contact 430a and has good adhesion to the pure Ag contact 430a), process stability, contact resistance, and / or mechanical resistance. Figure 4C illustrates an ITO layer 437c that can be in contact with a p-type GaN under an LED platform (not shown), wherein the ITO layer 437c is covered by an Ag base layer 430c. As shown in Figure 4C, a passivation layer 440c lies beneath at least a portion of an Ag substrate 430c and is in contact with an ITO layer 437c (and the Ag substrate 430c). Figure 4D illustrates a thin Ni layer 438d covered by an Ag substrate 430d, wherein a passivation layer 440d is in contact with both the thin Ni layer 438d and the Ag substrate 430d. In some embodiments, the Ni layer 438d may have a thickness of less than 10 nanometers (nm), less than 5 nm, less than 2 nm, less than 1 nm, less than 0.5 nm, or less than 0.1 nm. In some embodiments, the Ni layer may be continuous, for example, formed from Ni islands in the case of a very thin layer. In some embodiments, other metals (such as Pt) may be used instead of the thin Ni layer 438d. Figure 4E illustrates a thin Ni layer 438e embedded in an Ag matrix, for example, between a first Ag layer 430e1 and a second Ag layer 430e2. A passivation layer 440e contacts a thin Ni layer 438e, a first Ag layer 430e1, and a second Ag layer 430e2. In some embodiments, the thin Ni layer 438e may be discontinuous and (e.g., during a procedure, during device operation, etc.) may diffuse into the Ag layer 430e1 and / or the Ag layer 430e2. Figure 4F illustrates an alternative example of the example of Figure 4A. In the example of Figure 4F, a passivation layer 440f is disposed on top of an Ag layer 430f (rather than below the pure Ag contact 430a in Figure 4A). In some embodiments, the Ag layer 430f may include a first Ag contact layer and a second Ag contact layer above the first Ag contact layer, the second Ag contact layer being disposed within a recess (opening) defined in the passivation layer 440f. In some embodiments, variations and combinations of elements other than those specifically shown in Figures 4A to 4F are also possible. In some embodiments, the Ag layer (e.g., the Ag substrate) may have a thickness of at least 50 nm (at least 100 nm, at least 150 nm, or at least 200 nm). In some embodiments, a metal / semiconductor interface (e.g., an interface between a metal contact and a semiconductor structure) can be characterized by a high reflectivity (e.g., a high reflectivity level at one emission wavelength of an associated LED). For example, in some embodiments, the reflectivity can be higher than a target value (e.g., 80%, 90%, 95%, or 97%). In some embodiments, using the methods described above, the reflectivity can be maintained at a relatively high level over time (e.g., during operation of the corresponding device). In some implementations, at an operating current density (e.g., at least 1 ampere per square centimeter (A / cm²) 2 A device that operates for an extended period of time (e.g., 1000 hours or more) may have a reflectivity that remains substantially constant. In some embodiments, this relatively stable reflectivity may be facilitated by the configuration (metal content) of a passivation layer (e.g., where the passivation layer removes impurities that would otherwise reduce or degrade the reflectivity). In some implementations, a metal / semiconductor interface can be characterized by parameters of an electrical contact. For example, in some implementations, an electrical contact may have a low (or zero) Schottky barrier. In some implementations, an electrical contact may have a resistance of less than 5e-1 ohms / cm. 2 (Ω / cm 2 Less than 1E-1 Ω / cm 2 Less than 5E-2 Ω / cm 2 Less than 1E-2 Ω / cm 2 Less than 5E-3 Ω / cm 2 or less than 1E-3 Ω / cm 2 One of them is contact resistivity. Figures 5A through 5F are schematic diagrams (e.g., cross-sectional views) illustrating various exemplary configurations (e.g., including the removal of a passivation layer) of a microLED device implemented using the methods described herein. Although not specifically shown in Figures 5A through 5F, the illustrated device (e.g., a microLED platform) may be disposed (formed, etc.) on a growth interface of an underlying semiconductor material (e.g., a GaN buffer layer). In the example of Figure 5A, a passivation layer 540a (e.g., a desorption passivation layer) is formed on at least a portion of the p-type top surface and sidewalls of a micro-LED platform 520a. In some embodiments, the sidewalls may be p-type doped, n-type doped, or contain a pn junction. In some embodiments, an Ag-based p-type junction 530a is formed on a portion of the p-type top surface of the micro-LED platform 520a and contacts the passivation layer 540a. In the example of Figure 5B, a p-type contact of a micro-LED platform 520b includes a metal stack, for example, including a p-type contact 530b1 and a p-type contact 530b2 (either of which may be Ag-based). In some embodiments, other p-type contact layers (in addition to an Ag-based contact layer) may include one or more other metals, such as Al, Pt, gold (Au), Ni, Ti, Pd, and / or transparent conductive oxides (such as ITO, ZnO, etc.). In some embodiments, the p-type contact 530b1 is at least partially formed in an opening in a passivation layer 540b (e.g., a pull-out passivation layer). In the example of Figure 5C, a p-type contact layer 530c1 (e.g., an Ag substrate) is formed as a p-type layer contact to a micro-LED platform 520c. The p-type contact layer 530c1 is covered by a passivation layer 540c (e.g., a desorption passivation layer), and an opening is formed in the passivation layer 540c. At least one additional metal layer (e.g., a metal layer 530c2) may be formed, wherein at least a portion of the metal layer 530c2 is disposed in the opening in the passivation layer 540c and contacts the p-type contact layer 530c1. The p-type contact layer 530c1 and the metal layer 530c2 may contain Ag and / or other metals, such as Ti, Pt, Ni, gold (Au), chromium (Cr), tungsten (W), and Al. In the example of Figure 5D, a passivation layer 540d (e.g., a desorption passivation layer) is formed on a portion of the top surface of a micro-LED platform 520d, but does not cover any portion of the sidewalls of the micro-LED platform 520d. In some embodiments, the sidewalls of the micro-LED platform 520d may be covered by a second passivation layer (made of the same material as passivation layer 540d or a different dielectric material). As in the example of Figure 5B, a p-type contact of a micro-LED platform 520d includes a metal stack, for example, including a p-type contact 530d1 and a metal layer 530d2 (either of which may be Ag-based). In some embodiments, other p-type contact layers (other than an Ag-based contact layer) may include one or more other metals, such as Al, Pt, Au, Ni, Ti, Pd, and / or transparent conductive oxides (such as ITO, ZnO, etc.). In some embodiments, the p-type contact 530d1 is at least partially formed in one of the openings in the passivation layer 540d. Figure 5E illustrates a microLED device similar to the example of Figure 5C, wherein the sidewalls of a microLED platform 520e are vertical, rather than sloped or inclined, and no semiconductor material laterally surrounds an associated active region (e.g., between the active region and the sidewalls). As in the example of Figure 5C, in the example of Figure 5E, a p-type contact layer 530e1 (e.g., an Ag substrate) is formed to a p-type layer contact of the microLED platform 520e. The p-type contact layer 530e1 is covered by a passivation layer 540e (e.g., a absorbent passivation layer), and an opening is formed in the passivation layer 540e. At least one additional metal layer (e.g., a metal layer 530e2) may be formed, wherein at least a portion of the metal layer 530e2 is disposed in the opening in the passivation layer 540e and contacts the p-type contact layer 530e1. In the example of Figure 5F, a p-type contact 530f is partially formed on the sidewalls and a top surface of a micro-LED platform 520f. In this example, the micro-LED platform 520f has a p-type layer (e.g., p-type GaN) surrounding a corresponding active region of the micro-LED platform 520f on its sidewalls. These p-type layers can be obtained by selective growth from a patterned opening (where growth progresses laterally) or by a regeneration step. In some embodiments, it can be advantageous if the sidewalls have a p-type doped semiconductor material (e.g., selective growth from (a number of) non-vertical planes and / or by a growth step), which can facilitate lateral carrier implantation into the active region. In this example, a passivation layer 540f (e.g., a desorption passivation layer) may be close to or in solid contact with the Ag-containing region of the p-type contact 530f. The exemplary structure of Figure 5F also includes a substrate dielectric layer 570 disposed around a substrate of the micro-LED platform 520f. The substrate dielectric layer 570 may, for example, correspond to a growth mask (or selective region growth mask) for growing a micro-LED platform 520f. In exemplary embodiments, the sidewalls of a micro-LED platform can have various geometries. For example, the sidewalls can be vertical, non-vertical, inclined, sloping, curved, etc. A quantum well corresponding to the active region may or may not extend to the sidewalls. In some embodiments, a p-type material (e.g., p-type GaN, p-type AlGaN) may be present on the sidewalls surrounding the active region. In some implementations, the passive material (adsorption passivation material) is in direct contact with an Ag-based material. In some instances, it is separated from the Ag-based material by a distance of less than 100 nm (less than 10 nm or less than 1 nm). Figure 6 is a flowchart illustrating an exemplary method 600 for generating an electronic device (such as an exemplary embodiment of a micro LED described herein). Depending on the specific embodiment, the operation of method 600 may be performed in a different order, additional operations may be performed, and / or the operations included in Figure 6 may be omitted. Therefore, method 600 is given by way of example and for illustrative purposes. As shown in Figure 6, method 600 includes forming a semiconductor structure at block 610. In some embodiments, the semiconductor structure may include an n-type doped region, an active region, and a p-type doped region formed on a buffer layer (e.g., a semiconductor substrate or template). At block 620, method 600 includes forming a micro-LED platform from the semiconductor structure of block 610. In some embodiments, a combination of dry and wet etching may be used to form the micro-LED platform. In some embodiments, the micro-LED platform has a top surface and sidewalls. In some embodiments, the top surface is doped (e.g., p-type doped). In some embodiments, the device has a lateral dimension (width) of less than 50 μm (less than 10 μm, less than 5 μm, less than 2 μm, or less than 1 μm). At block 630, a passivation layer (e.g., a removable passivation layer) is formed over at least a portion of the micro-LED platform. In some embodiments, this may include a portion of a sidewall and / or a portion of the top surface. At block 640, a metal contact layer (e.g., an Ag-based contact layer) is formed over a portion of the micro-LED platform. In some embodiments, this may include a portion of a sidewall and / or a portion of the top surface. In some embodiments, the metal contact layer may be at least partially formed in an opening defined in the passivation layer. In some embodiments, the passivation layer may be in close proximity to the metal contact layer (e.g., in direct physical contact). At block 650, the method includes performing a heat treatment operation. For example, the operation at block 650 may include at least one of an annealing operation on an Ag substrate, a semiconductor doping activation operation, a metal reflow operation, or a metal bonding operation. In some embodiments, during the heat treatment operation at block 650, the passivation layer formed at block 630 may have an impurity removal effect, thereby capturing diffused impurities and / or preventing such elements from reacting with the metal contact layer formed at block 640. For example, the passivation layer may remove oxygen and / or hydrogen, thereby preventing oxygen from reacting with a silver-based metal contact layer and / or preventing hydrogen from passivating a contact surface of the microLED at an interface with the metal contact layer. In some embodiments, the semiconductor structure can be formed using epitaxial growth techniques including metal-organic chemical vapor deposition (MOCVD) and molecular beam epitaxy (MBE). In some embodiments, the passivation layer can be formed using techniques including sputtering, electron beam deposition, atomic layer deposition, CVD, plasma-assisted CVD (PECVD), and high-density plasma (HDP) deposition. In some embodiments, co-deposition can be used, employing a combination of two or more of the aforementioned techniques. In some implementations, the metal contact layer can be formed by techniques including sputtering, electron beam, electroplating (e.g., electrochemical electroplating (ECP)) deposition. In some embodiments, the device generated by method 600 can be electrically operated. In some embodiments, the power may have a value of at least 0.1 A / cm². 2 (at least 1 A / cm) 2 At least 10 A / cm 2 Or at least 100 A / cm 2 The current density is one of the parameters. In some embodiments, this device can be characterized by stable operation (e.g., optical and / or electrical operation). In some embodiments, stable operation can be facilitated by the presence of a passivation layer (such as the passivation layer described herein). Stable operation can be contrasted with a device that exhibits hysteresis and / or optical instability over time. Stable operation can be characterized by a stable light-current-voltage characteristic of an LED. For example, hysteresis less than or equal to 50 millivolts (mV) can confirm stable operation. In some instances, the passivation layer can absorb charged defects. In some embodiments, this absorption of charged defects can prevent such defects from causing unstable operation of an associated device. In some embodiments, the charged defect can be one or more of a charged atom, a charged compound, a native semiconductor defect (such as a vacancy), etc. In some embodiments such as those described herein, after the processing operation of block 650 of method 600, a p-type contact can have a capacitance of less than 1e-2 ohm cm⁻¹. 2 (less than 1E-3 Ohm cm) 2 or less than 1e-4 Ohm cm 2 One of the specific contact resistances. Figure 7 is a graph 700 illustrating one of the experimental results, which confirm that a passivation layer can improve the electrical stability of an LED. Trace 750 shows the experimental results for a microLED with a passivation layer, and trace 760 shows the experimental results for a microLED without a passivation layer. The experimental results in Figure 7 are for a microLED device approximately 2 µm (in diameter) with a metal contact layer (e.g., an Ag-based p-type contact). The experimental results shown in Figure 7 were collected by operating each microLED with an electric current, causing one of the light-emitting regions of the microLED to emit light. For the microLED device corresponding to trace 750, during operation, the dielectric passivation layer promotes stable operation of the LED as described herein. In Figure 7, each set of traces (traces 750 and 760) illustrates the respective relationship between the measured voltage and current density of the corresponding LED, with an upward sweep (as voltage increases) followed by a downward sweep (as voltage decreases). In an example of Figure 7, dashed lines represent the respective upward sweeps, while solid lines represent the respective downward sweeps. In this example, the device without a passivation layer (trace 760) exhibits unstable JV characteristics, where the upward and downward sweep voltages vary by up to 1 V at a given current (e.g., when the LED operates under hysteresis). Furthermore, in contrast, in this example, the device including a passivation layer (trace 750) exhibits stable JV characteristics; the upward and downward sweeps overlap in Figure 7, thus demonstrating no or negligible hysteresis. In some embodiments, removing the passivation layer promotes this stable JV characteristic by passivating the electrical traps. In some examples, an unstable (or transient) JV curve of a prior device embodiment (e.g., without a passivation layer removal) may become more stable after operation, at least for a finite period of time (e.g., an aging step). In contrast, a device produced using the method described herein can operate with a stable JV curve without an aging step, for example, this may be stable after a first operation and remain stable over an extended period of time during a service life. In some implementations, stability can be achieved by maintaining a predetermined current or current density (e.g., 0.1 A / cm²). 2 1 A / cm 2 10 A / cm 2The stability is characterized by a voltage variation of less than a predetermined value (e.g., 1 V, 0.1 V, 0.05 V, 0.02 V). In some embodiments, the variation may occur between an upward sweep (voltage increase) and a subsequent downward sweep (voltage decrease), and a passivation laser can reduce or remove this variation. In some embodiments, stability can be observed as maintaining a stable current for a time period (e.g., at least 1 microsecond (µs), 1 millisecond (ms), 1 second (s), 1 minute (min), 1 hour (hr)). In some embodiments, stability can be observed by performing two measurements at the same current over a time period (e.g., within 1 µs, 1 ms, 1 s, 1 min, 1 hr). In some embodiments, stability can be sustained for at least 1 day (or 1 month or 1 year). In some embodiments, a device (e.g., a microLED) driven at a predetermined current for at least 1 s (at least twice a day) can have a stable voltage of less than 0.1 V when driven at the predetermined current. In some embodiments, a barrier layer may be included in the contact metal stack, wherein the barrier layer may, for example alone or in combination with an absorbent passivation layer as described herein, improve the stability of a contact. As mentioned above, an interface (electrical contact interface) between a contact metal (e.g., an Ag-based contact metal) and an underlying semiconductor material (e.g., a p-type GaN layer of a microLED) may be sensitive to the presence of hydrogen. For example, hydrogen diffusion during a process step may passivate the semiconductor material and thus degrade or increase an associated contact resistance. Furthermore, the metal contact layer and / or reflector layer may be sensitive to the presence of oxygen, which can oxidize the metal layer and degrade or reduce its optical properties (e.g., its reflectivity). In the exemplary embodiments illustrated in Figures 8, 9, and 10, a barrier layer is included in the metal stack (e.g., a contact metal stack), wherein the barrier layer prevents or slows down (suppresses, reduces, etc.) the movement of hydrogen and / or oxygen toward an associated contact interface and / or a reflective metal layer. This barrier layer may contain a conductive compound. For example, a barrier layer may have a conductivity less than 1e. -3 The resistivity is one ohm·cm. In some embodiments, one layer of this conductive compound (barrier layer) may have a resistivity of less than 10 ohms·cm. 5 The resistance of an ohm. In the following discussion, exemplary metallic structures comprising respective barrier layers are described with reference to Figures 8 through 10. These contact structures may be incorporated, for example, into a micro-LED or other semiconductor (electronic) device. Following the discussion of the exemplary structures of Figures 8 through 10, details of exemplary embodiments of these structures are described. Of course, the specific details of a given device will depend on the particular embodiment. Figure 8 illustrates one embodiment of a contact metal stack 800 having a planar layer (e.g., a cross-sectional view of the contact metal stack 800). In this example, the contact metal stack 800 is formed on a surface 828 of a p-type layer (e.g., p-type GaN) of a micro-LED platform. The contact metal stack 800 includes an Ag base contact 830 disposed (e.g., directly on) the surface 828. The contact metal stack 800 further includes a metal layer 835a (e.g., metal_1 layer) disposed on the Ag base contact 830, a barrier layer 870 disposed on the metal layer 835a, and a metal layer 835b (e.g., metal_2 layer) disposed on the barrier layer 870. In this example, the contact metal stack 800 also includes a passivation layer 840 disposed adjacent to and in contact with the metal layer stack including the Ag base contact 830, metal layer 835a, barrier layer 870, and metal layer 835b. Depending on the implementation, passivation layer 840 may be a removable passivation layer (such as the removable passivation layer described herein) and may provide a removal function for impurities, such as that described with respect to FIG2. In some implementations, passivation layer 840 may be a passivation layer that does not provide a removal function. Figure 9 illustrates a schematic diagram (e.g., a cross-sectional view of a contact metal stack 900) comprising both planar and non-planar layers. In this example, the contact metal stack 900 is formed on a surface 928 of a p-type layer (e.g., p-type GaN) of a micro-LED platform. The contact metal stack 900 includes an Ag base contact 930 (e.g., a planar contact layer) disposed (e.g., directly on) surface 928. The contact metal stack 900 further includes a metal layer 935a (e.g., a non-planar metal layer) disposed on and encapsulating (at least partially surrounding) the Ag base contact 930. The contact metal stack 900 further includes a barrier layer 970 (e.g., a non-planar barrier layer) disposed on and encapsulating (at least partially surrounding) the metal layer 935a. The contact metal stack 900 further includes a metal layer 935b (e.g., a non-planar metal_2 layer) disposed on and encapsulating (at least partially surrounding) one of the barrier layers 970. In this example, the contact metal stack 900 also includes a passivation layer 940 disposed adjacent to and contacting the metal layer 935b of the metal layer stack comprising the Ag base contact 930, metal layer 935a, barrier layer 970, and metal layer 935b. Depending on the embodiment, the passivation layer 940 may be a pull-out passivation layer (such as a pull-out passivation layer described herein) and may provide a pull-out function for impurities, such as that described at least with respect to FIG2. In some embodiments, the passivation layer 940 may be a passivation layer that does not provide a pull-out function. Figure 10 illustrates an example of a microLED 1000 including an Ag base junction 1030 encapsulated by a barrier layer 1070 (e.g., a cross-sectional view). The microLED 1000 further includes an absorbent passivation layer 1040 (such as an absorbent passivation layer described herein) disposed on a portion of the sidewall and an upper surface of a microLED platform 1020 of the microLED 1000. Similar to the microLED 100 of Figure 1, the microLED 1000 of Figure 10 includes a buffer layer 1010 (e.g., a gallium nitride (GaN) buffer layer) having a growth interface surface 1015, for example, for epitaxial growth of the microLED platform 1020. As shown in Figure 10, like the microLED 100, the microLED platform 1020 of the microLED 1000 includes at least one n-type doped layer 1022, an active region 1024 (active QW region), and at least one p-type doped layer 1026. In this example, the microLED platform 1020 has inclined or sloping sidewalls. In some embodiments, a microLED may have vertical and / or other shaped sidewalls. As shown in Figure 10, the microLED platform 1020 has a p-type doped top (upper) surface 1028 (e.g., p-type GaN) on which a contact metal stack is formed and on which a portion of an absorbent passivation layer 1040 is disposed. In exemplary embodiments of the structures shown in Figures 8 to 10, a barrier layer (e.g., barrier layer 870, barrier layer 970, and / or barrier layer 1070) may have at least one of the following properties or attributes: A barrier layer may be conductive. For example, a barrier layer may have a conductivity of less than 10. -3 Ω.cm (less than 10) -4 Ω.cm, less than 10 -5 Ω.cm or less than 10 -6 A resistivity of one Ω·cm, or having a resistivity less than 10 5 Ω (less than 10) 4 Ω or less than 10 3 A barrier layer has a resistance of Ω. A barrier layer may exhibit metallic behavior. A barrier layer may contain or contain nitrogen. A barrier layer may be a metal-nitrogen compound. The metal may be one of titanium (Ti), magnesium (Mg), cobalt (Co), tantalum (Ta), or tungsten (W), which have one of the following metal-nitrogen chemical formulas: TiN, MgN, CoN, TaN, or WN. For example, possible chemical compositions for a barrier layer may contain titanium nitride (such as TiN), magnesium nitride (such as Mg), etc. 3N 2) Cobalt nitride (such as Co) 3N 2 or Co(NO) 3) 3) Tantalum nitride (such as TaN, Ta) 2N) or tungsten nitride (such as W) 3N). In some embodiments, the ideal proportions and / or phases of a material used in a barrier layer can be selected to impart a desired resistivity. Therefore, in some embodiments, the precise ideal proportions of a barrier layer material may differ from those of the compounds listed above. A barrier layer material may be heterogeneous. It may contain, for example, regions embedded in a matrix that are effective for hydrogen removal (such as islands / clusters of nitrogen-rich materials) and / or regions that are effective for oxygen removal (such as regions of materials described herein). In the structures illustrated in Figures 8 to 10, an example of a contact stack comprising an underlying semiconductor material or structure, in the order of stacking, may be a heavily doped p-type GaN surface / Ag-based contact layer / metal_1 layer, a barrier layer, and a metal_2 layer. The Ag-based contact layer may be an Ag contact layer, as described herein. That is, the Ag contact layer may be a region primarily composed of Ag. The region may contain small amounts of other materials, such as a thin (less than 5 nm) interface (e.g., Ni) layer or a thin (e.g., Ni) layer embedded in an Ag matrix. The barrier layer may be a barrier layer, as described herein. The metal_1 layer may be a first metal material stack, and the metal_2 layer may be a second metal material stack. In some embodiments, the metal_1 layer and the metal_2 layer may each comprise at least one layer of a metal containing Ti, Ni, Au, Pt, Al, W, Cr, and / or alloys thereof. In some implementations, the composition of the metal_1 layer and the metal_2 layer can be selected to improve adhesion, reduce strain to act as a diffusion barrier, achieve the desired resistance, etc. In some embodiments, variations in the contact stack are possible. For example, an electrical contact having a p-type GaN material can be made using a metal other than Ag or using a stack (such as an ITO / Ag stack, an ITO / Al stack, or a stack containing other transparent conductive oxides). In some embodiments, the metal_1 layer and / or metal_2 layer can be omitted. Additional layers (e.g., metal layers) can be formed on top of the stack (such as a copper (Cu) layer and other layers required for a metal damascene process or a hybrid bonding of a corresponding microLED to a backplane). In some embodiments, a contact stack can be formed using at least one of electron beam evaporation, sputtering, atomic layer deposition, or thermal deposition. In some embodiments, a barrier layer has a high density or a density sufficient to block the diffusion pathway of hydrogen and / or oxygen (e.g., nitrogen). In some instances, the barrier layer is deposited using a technique that promotes a high density (such as sputtering or ALD). The surrounding layer may be deposited using another technique (e.g., electron beam evaporation). In some embodiments, a barrier layer may have a thickness greater than 1 nm, 5 nm, 10 nm, 50 nm, or 100 nm. In some embodiments, an LED including a barrier layer may be generated by method 600 of FIG. 6 or a variation thereof. For example, a barrier layer may be formed after a metal contact is formed at block 640 in method 600. Method 600 may also include operations at block 640 for forming a metal_1 layer and / or a metal_2 layer. For example, in one instance, the metal_1 layer may be formed before the barrier layer is formed, and the metal_2 layer may be formed after the barrier layer is formed. That is, the operation at block 640 may include forming a metal contact stack, such as the examples in FIG. 8 to FIG. 10. Furthermore, depending on the specific embodiment, the passivation layer formed at block 630 may be a desorption passivation layer or other passivation layer. In some embodiments, the passivation layer may be formed after a contact stack is formed, for example, the operations at blocks 630 and 640 may be reversed. In some embodiments, for a device including a barrier layer, the heat treatment operation of block 650 of method 600 may be a treatment operation performed in the presence of hydrogen and / or oxygen (e.g., hydrogen and / or oxygen diffused from the device being generated and / or present in the surrounding environment of the treatment operation). For example, as some examples, the heat treatment operation may include at least one of a cleaning operation (e.g., a chemical cleaning), a descum removal operation, an annealing operation (e.g., in a rapid thermal annealing (RTA) chamber), an etching operation, or a material deposition operation. Figure 11 is one of the experimental data sets, graph 1100, which demonstrates the benefits of using a barrier layer in a microLED. The experimental data is collected from microLEDs produced on two separate semiconductor wafers. A first wafer, corresponding to a curve fitting dataset 1160, contains a microLED with a contact metal stack without a barrier layer (and without a passivation layer). A second wafer, corresponding to a curve fitting dataset 1150, contains a microLED with a contact metal stack having a barrier layer (such as a barrier layer described herein) and without a passivation layer. In Figure 11, symbols (dots) indicate measurements for several devices, and curves fit this data. Both wafers undergo a processing operation in which SiOx is deposited on the microLED using a tetraethoxysilane (TEOS) precursor. Hydrogen released during this process can migrate through the material containing the metal stack and passivate the p+ GaN surface, resulting in a high contact resistance. The experimental results illustrated in Figure 11 were collected by operating each microLED with an electric current, causing one of the light-emitting regions of the LED to emit light. For the microLED device corresponding to the curve-fitted dataset 1150, the barrier layers facilitated stable operation of the LED as described herein during their operation. Figure 11 shows curve fitting datasets 1150 and 1160, illustrating the current-voltage characteristics of their respective microLEDs. For the wafer corresponding to curve fitting dataset 1160 (without a barrier layer), hydrogen diffuses through the metal stack and the operating voltage is relatively high for a given operating current density (e.g., at 10 A / cm). 2 (One of the operating current densities is greater than 5 V). For the wafer corresponding to the curve fitting dataset 1150 (containing a barrier layer), the barrier layer reduces hydrogen diffusion, resulting in a current density greater than 10 A / cm. 2 One operating current density is less than 3 V, and one operating voltage is less than 3 V. In this example, the wafer system corresponding to the curve fitting dataset 1150 in Figure 11 is an example of a wafer having a silver-based p-type junction and a barrier layer, which maintains a low operating voltage after a TEOS process step. In some embodiments, a TEOS-based deposition process can be used to deposit a silicon oxide layer (e.g., a conformal layer) to prepare for a hybrid bonding process such as coupling (attaching, etc.) a microLED array to a backplane to form a microLED display. TEOS-based deposition can form a layer with a thickness of at least 100 nm or at least 1 µm. In some embodiments, processing operations (e.g., semiconductor manufacturing operations) may introduce significant amounts of hydrogen and / or oxygen. Examples of such processing operations may include: depositing a material in a hydrogen- and / or oxygen-containing environment; depositing a material having a hydrogen- and / or oxygen-containing precursor; annealing in a hydrogen- and / or oxygen-containing environment; or performing a high-temperature operation (e.g., greater than 300ºC, greater than 400ºC, or greater than 500ºC) in a hydrogen- and / or oxygen-containing environment. In some embodiments, a conductive barrier layer may be configured such that the hydrogen flow rate to a p-type surface of a corresponding LED platform is less than 10 during a processing operation. 13 cm -2 For example, the conductive barrier layer can be configured (e.g., having a composition and / or density) such that, due to diffused hydrogen during the processing operation, the additional hydrogen concentration near the p-type surface after the processing operation is less than 10. 19 cm -3 . It is desirable to limit the diffusion of hydrogen and / or oxygen toward the semiconductor material and / or associated interfaces (e.g., interfaces with a conductive layer, semiconductor material, or insulating layer). In some embodiments, this diffusion may be limited by the use of a passivation material (such as the passivation material described herein) covering a portion of the LED sidewall, wherein the passivation material acts as a hydrogen barrier / absorber and / or as an oxygen barrier / absorber. In some embodiments, a barrier layer or material (such as the barrier layer or material described herein (e.g., in a metal contact)) may be used, wherein the barrier material acts as a hydrogen barrier / absorber and / or as an oxygen barrier / absorber. In some embodiments, the passivating material may comprise materials such as those described herein, as well as other materials. For example, in some embodiments, the passivating material may comprise at least one of BeN, BeAlN, BeBN, BeO, CaN, CaAlN, CaBN, CaO, MgN, MgAlN, MgBN, MgO, SiN, SiOx, SiAlN, AlOx, SiOxNy, SiCxNy, and / or compounds based on group II nitrides (where x and y represent ideal proportions). In some embodiments, a passivating material may be a composition of different materials (e.g., including those described herein). For example, such passivating materials may also be a compound (mixture) of materials or a layered stack of multiple materials. For example, in some embodiments, a passivating material may have one or more layers of AlOx, and one or more layers of BeN, BeAlN, BeBN, BeO, CaN, CaAlN, CaBN, CaO, MgN, MgAlN, MgBN, MgO, SiN, SiOx, SiAlN, SiOxNy, or SiCxNy. In some implementations, a passivation material may be electrically insulating. For example, a passivation material may have at least 10 4 Ω.cm (at least 10) 6 Ω.cm or at least 10 8 A resistivity of Ω·cm. A passivation material can have a resistivity greater than 10. -12 m 2 (For example, at least 1 μm) 2 ), or less than 10 -10 m 2 (For example, less than 10 μm) 2 ), or in 10 -12 Up to 10 -10 m 2 An area within a certain range. In some embodiments, a passivation material may have a thickness of at least 0.5 nm (at least 1 nm, at least 5 nm, at least 10 nm, at least 50 nm, at least 100 nm, at least 500 nm), or a thickness in the range of 1 to 100 nm or in the range of 10 to 1000 nm. In some embodiments, a passivation material may be formed by means of at least 10 7 Ω (at least 10) 8 Ω, at least 10 9 Ω or at least 10 10 The resistance characteristics of an LED are characterized by a resistance of Ω. A passivation material can conduct a current of less than 10 nA, less than 1 nA, or less than 0.1 nA during the operation of an LED. In exemplary embodiments, both the optical and electrical benefits of the methods described herein (e.g., using a passivation layer and / or a barrier layer in a contact metal stack) can be achieved in an electronic device (such as a microLED). Therefore, an LED (e.g., a microLED) may individually or in combination have one or more of the following properties or characteristics. In some embodiments, an LED may have a size (lateral dimension) of less than 20 µm (less than 10 µm, less than 5 µm, less than 3 µm, less than 2 µm, less than 1.5 µm, or less than 1 µm). In some embodiments, an LED may have a minimum A / cm² of 0.1 A. 2 (at least 1 A / cm) 2 Or at least 10 A / cm 2 It has an electro-optical conversion efficiency of at least 1% (at least 3%, at least 5%, at least 10%, or at least 20%) at a current density of at least 1%. In some embodiments, an LED can operate at a wavelength of at least 400 nm (at least 500 nm or at least 600 nm). In some embodiments, a high-temperature operation refers to an operation that occurs or is performed at a temperature significantly higher than room temperature (e.g., 100ºC or more above room temperature). In some embodiments, a high-temperature operation may occur at a temperature above 150ºC, 200ºC, 300ºC, 400ºC, or 500ºC. In some implementations, for a micro LED, a lateral dimension can be defined as the side dimension of a square LED; the diameter of a circular LED; or more generally, a typical dimension of the lateral range of a characteristic LED. The embodiments described herein offer several benefits. For example, the embodiments, together with the stable optical behavior of an Ag-based reflector (as seen, for example, in Figure 3), provide a stable electrical passivation (using low voltage and without hysteresis, as seen, for example, in Figure 7). This contrasts with other materials that cannot simultaneously provide at least two of these benefits. In some implementations, maintaining good electrical and optical performance becomes increasingly difficult as LED size decreases. Indeed, in devices with small dimensions (micro-LEDs) such as those described herein, impurities diffusing over short distances can cause (electrical and / or optical) degradation of a reflector. Similarly, the larger perimeter-to-area ratio of small devices can make them more sensitive to charge trapping, leading to operational instability. In some cases, this can cause an undesirable performance cliff below a certain size (e.g., less than 10 µm or less than 5 µm). The implementations described herein offer the benefit of promoting good electrical and optical performance for very small devices (e.g., less than 2 µm, or even less than 1 µm). In some embodiments, an LED having a barrier layer and / or a desorption passivation layer may have an operating voltage of less than 5V (less than 4V, less than 3.5V, or less than 3V) after a programmed operation (such as a TEOS-based deposition), wherein the programmed operation is performed in the presence of hydrogen (and / or oxygen). The programmed operation may be performed at a temperature of at least 200ºC (at least 300ºC, at least 400ºC, or at least 500ºC). In some embodiments, a microLED display using a microLED comprising a barrier layer and / or a desorption passivation layer may have an LED operating voltage of less than 5V (less than 4V, less than 3.5V, or less than 3V) or less than the energy of an emitted photon (e.g., in electron-volts) plus 2V (plus 1.5V, plus 1V, or plus 0.5V), wherein the operating voltage is at least 10 A / cm². 2 Measured at one of the operating current densities or at a current of at least 100 nA or at least 1 µA. The embodiment includes a semiconductor platform having an n-type doped region, an active region (e.g., a quantum well light-emitting region), and a p-type region terminated by a p-type surface. The platform may be formed on a template (e.g., in its bottom region), or the surface may be in direct contact with the template. The p-type surface may coincide with a top surface of the platform, or the p-type surface may surround a region of the platform, in which case the p-type region may be an outer region of the platform (e.g., including a top portion and sidewall regions). In a typical configuration, an electronic device includes: a semiconductor structure comprising a doped surface; a silver-based (Ag-based) layer electrically contacting at least a portion of the doped surface; and a passivation layer disposed on a portion of the semiconductor structure. A portion of the passivation layer is in contact with the Ag-based substrate. The passivation layer comprises a compound of a group II nitride material. The implementation scheme may include one or more of the following features or states, individually or in combination. For example, the doped surface may be at least one of the top surface of the semiconductor structure or the surface of an epitaxial layer. The semiconductor structure may include a sidewall surface. At least a portion of the passivation layer may be disposed on the sidewall surface. A first portion of the Ag substrate may be disposed on the doped surface. A second portion of the Ag substrate may be disposed on the passivation layer. The electronic device may have a lateral dimension of less than or equal to 10 micrometers (µm). The semiconductor structure may contain a group III nitride material. The group II nitride material may contain at least one of magnesium nitride, calcium nitride, or beryllium nitride. The material compound may contain Group III elements. The passivation layer may contain at least 90 percent of the group II nitride material based on the composition. The semiconductor structure may include a layer containing gallium nitride (GaN) and a light-emitting layer containing indium gallium nitride (InGaN). The electronic device may be a light-emitting diode (LED). The LED may include a platform having a top surface, a sidewall, and a substrate. The passivation layer may cover a portion of the top surface and a portion of the sidewall. For light having a wavelength in the range of 450 to 650 nanometers (nm), the interface between the Ag substrate and the doped surface can have a reflectivity of more than 90 percent. For light having a wavelength in the range of 450 to 650 nanometers (nm), the passivation layer may have a refractive index greater than 1.7. The passivation layer can be configured to absorb at least one of oxygen or hydrogen. The passivation layer can be configured to trap mobile charges. In another general example, a micro light-emitting diode (microLED) includes: a semiconductor structure having a doped surface; and a light-emitting region. The microLED also includes: a metal substrate electrically contacting at least a portion of the doped surface; and a passivation layer disposed on the semiconductor structure. A portion of the passivation layer is in solid contact with the metal substrate. The passivation layer is a compound comprising a group II nitride material. The microLED has a lateral dimension of less than or equal to 10 micrometers (µm). The implementation scheme may include one or more of the following features or states, individually or in combination. For example, the metal substrate may be an Ag substrate. A first portion of the Ag substrate may be disposed on the doped surface. A second portion of the Ag substrate may be disposed on the passivation layer. The semiconductor structure may contain a group III nitride material. The group II nitride material may contain at least one of magnesium nitride, calcium nitride, or beryllium nitride. The compound may further contain a group III element. The passivation layer may contain at least 90 percent of the group II nitride material based on the composition. The semiconductor structure may include a layer containing gallium nitride (GaN) and a light-emitting layer containing indium gallium nitride. For light having a wavelength in the range of 450 to 650 nm, the interface between the metal substrate and the doped surface may have a reflectivity greater than 90 percent. For light having a wavelength in the range of 450 to 650 nm, the passivation layer may have a refractive index higher than 1.7. The passivation layer can be configured to absorb at least one of oxygen or hydrogen. The passivation layer can be configured to trap mobile charges. In another general embodiment, an LED comprises: a semiconductor structure having a doped surface and a light-emitting region; a silver-based (Ag-based) layer electrically contacting at least a portion of the doped surface; and a passivation layer formed on a surface of the semiconductor structure. A portion of the passivation layer is in contact with the Ag-based substrate. The passivation layer comprises a chemical element X having an enthalpy of formation of oxide XO greater than 500 kJ / mol. The implementation may include one or more of the following features or states, individually or in combination. For example, the passivation layer may contain a compound of X and nitrogen. A first portion of the Ag substrate may be disposed on the doped surface. A second portion of the Ag substrate may be disposed on the passivation layer. The LED may have a lateral dimension of less than or equal to 10 µm. The semiconductor structure may contain a group III nitride material. X can be a group III element. The passivation layer may contain a group III element. The passivation layer may contain at least 10 percent X based on the composition. The semiconductor structure may include a layer containing gallium nitride (GaN) and a light-emitting layer containing indium gallium nitride (InGaN). For light having a wavelength in the range of 450 to 650 nm, the interface between the Ag substrate and the doped surface can have a reflectivity greater than 90 percent. For light with a wavelength in the range of 450 to 650 nanometers (nm), the passivation layer has a refractive index greater than 1.7. The passivation layer can be configured to absorb at least one of oxygen or hydrogen. The passivation layer can be configured to trap mobile charges. In another general example, a method for generating a light-emitting diode (LED) includes forming a silver-based (Ag-based) layer on a doped surface of a semiconductor structure comprising a light-emitting region. The Ag-based layer is electrically contacted with the doped surface. The method also includes forming a dielectric layer on the semiconductor structure. The dielectric layer is adjacent to the Ag-based layer. After forming the Ag-based layer and the dielectric layer, the method includes performing a thermal processing operation on the semiconductor structure, wherein the dielectric layer is configured to maintain a reflectivity of the Ag-based layer greater than or equal to 80% for light at a wavelength of 500 nm after the thermal processing operation. The implementation scheme may include one or more of the following features or states, individually or in combination. For example, the dielectric layer may comprise a group II nitride material. The dielectric layer may contain a chemical element X, which is an oxide XO with a formation enthalpy greater than 500 kJ / moles. The heat treatment operation may be performed at least in part at a temperature greater than or equal to 300°C. The heat treatment operation may be one of the following: an annealing operation, a semiconductor doping activation operation, a metal reflow operation, or a metal bonding operation for the Ag substrate. Maintaining this reflectivity may involve the dielectric layer absorbing at least one of hydrogen or oxygen during the heat treatment operation. This dielectric layer can trap mobile charges. Forming the dielectric layer may include forming the dielectric layer such that at least a portion of the dielectric layer is in contact with the Ag substrate. A chemical species may be present during this heat treatment operation. The dielectric layer can absorb the chemical species. The chemical species may be either oxygen or hydrogen. In another general example, for a light-emitting diode (LED), an operating method includes operating the LED with an electric current such that a light-emitting region of the LED emits light. The LED has: a semiconductor structure having a doped surface and a light-emitting region; a silver-based (Ag-based) layer electrically contacting at least a portion of the doped surface; and a dielectric passivation layer comprising a group II nitride material formed on a surface of the semiconductor structure, wherein a portion of the dielectric passivation layer is in contact with the Ag-based substrate. The dielectric passivation layer is configured to promote stable operation of the LED during the operation. The implementation scheme may include one or more of the following features or states, individually or in combination. For example, facilitating stable operation of the LED may include trapping mobile charges in the dielectric passivation layer. The stable operation of this LED can be characterized by its substantially constant light output over time. Stable operation of the LED can be characterized by the hysteresis of its current-voltage characteristic being below a threshold value. This threshold value can be 50 millivolts at the LED's operating current. This operating current corresponds to a current density greater than 1 ampere per square centimeter in the light-emitting area. The LED can have a lateral dimension of less than 10 micrometers. For light of a wavelength of 500 nanometers emitted from the luminescent region, the Ag substrate may have a reflectivity of greater than or equal to 90%. In another general example, a method for generating a light-emitting diode (LED) includes: forming a semiconductor LED platform; forming a protective layer on the semiconductor LED platform; forming a metal contact on the semiconductor LED platform; and performing a processing operation on the LED. The processing operation causes the release of a species. The protective layer is configured to reduce the diffusion of the species toward the semiconductor LED platform. The implementation scheme may include one or more of the following characteristics or states, alone or in combination. For example, the species may be oxygen or hydrogen. The semiconductor LED platform may have a sidewall, and the protective layer may cover a portion of the sidewall. This protective layer can absorb the species. The protective layer may contain one of the chemical elements X that reacts with the species to form either oxide XO or hydride XH. This protective layer can be used as a diffusion barrier against one of the species. The protective layer may have a thickness of at least 5 nm. This protective layer can trap mobile charges. This metal contact can be an Ag-based contact. The protective layer can be in direct contact with the Ag base junction and can cause the Ag base junction to maintain a high reflectivity during the processing operation. This protective layer can reduce the spread of the species toward the Ag base junction. In another general example, a light-emitting diode (LED) includes: a semiconductor platform having an n-type doped region; an active region; and a p-type doped region terminated by a p-type surface. The LED also includes a p-type contact disposed on a portion of the p-type surface. The p-type contact includes: an Ag substrate electrically contacting the p-type surface; and a metal stack encapsulating the Ag substrate. The metal stack includes at least one layer of a conductive compound containing a metal and nitrogen. The implementation may include one or more of the following features or states, alone or in combination. For example, the conductive compound may be used as a diffusion barrier against hydrogen. The metal may contain one of titanium, magnesium, cobalt, tantalum or tungsten. The conductive compound may contain one of titanium nitride, magnesium nitride, cobalt nitride, tantalum nitride, or tungsten nitride. This conductive compound can have a conductivity less than 1e. -3 ohm.cm is one of the resistivity values. The at least one layer of the conductive compound may have less than 10 5 One of the resistors in the ohm series. The metal stack may include a first metal disposed between the Ag substrate and the conductive compound, and a second metal disposed on the conductive compound opposite to the Ag substrate. The Ag base layer can be in direct contact with the p-type surface. A transparent oxide can be placed between the Ag substrate and the p-type surface. The LED may have a first hydrogen concentration in the Ag substrate and a second hydrogen concentration on the side of the at least one layer of the conductive compound opposite to the Ag substrate. The second hydrogen concentration may be at least ten times the first hydrogen concentration. In another general embodiment, a light-emitting diode (LED) includes: a semiconductor platform having an n-type doped region; a light-emitting region; a p-type doped region terminated by a p-type surface; and at least one sidewall. The LED also includes a p-type contact formed on a portion of the p-type surface. The p-type contact includes at least one layer of a conductive compound containing a first metal and nitrogen. The LED further includes a passivation layer formed on a portion of the at least one sidewall. The passivation layer includes at least one layer of an insulating compound containing a second metal and nitrogen. The implementation may include one or more of the following features or states, alone or in combination. For example, the conductive compound may be used as a diffusion barrier against hydrogen. The first metal may include one of titanium, magnesium, cobalt, tantalum or tungsten. The conductive compound may contain one of titanium nitride, magnesium nitride, cobalt nitride, tantalum nitride, or tungsten nitride. This conductive compound can have a conductivity less than 1e. -3 ohm.cm is one of the resistivity values. The at least one layer of the conductive compound has a density of less than 10. 5 One of the resistors in the ohm series. The LED may include a third metal disposed between the p-type contact and the conductive compound, and a fourth metal disposed on the conductive compound opposite to the p-type contact. The second metal may include one of magnesium, calcium, or beryllium. The insulating compound may contain one of magnesium nitride, calcium nitride, or beryllium nitride. In another general example, a method for producing an LED includes: forming a p-type contact in direct contact with a p-type surface of an LED semiconductor platform; and forming a metal stack on the p-type contact, wherein the metal stack has a conductive barrier layer. The method also includes performing a processing operation on the LED. This processing operation uses or causes the release of hydrogen. The conductive barrier layer is configured to reduce the diffusion of hydrogen through the p-type contact to the p-type surface during the processing operation. The implementation scheme may include one or more of the following features or states, individually or in combination. For example, the p-type contact may be Ag-based. The conductive barrier layer can be configured such that the hydrogen flow rate to one of the p-type surfaces is less than 10 during the processing operation. 13 cm -2 . The conductive barrier layer can be configured such that, due to the diffusion of hydrogen during the processing operation, the additional hydrogen concentration near the p-type surface after the processing operation is less than 10. 19 cm -3 . This processing operation may involve depositing silicon oxide using a TEOS precursor. This processing operation can be performed at a temperature above 300ºC. The p-type contact can have less than 1e after this processing operation. -4 ohm cm 2 One of the specific contact resistances. It should be understood that in the foregoing description, when an element is referred to as being on, connected to, electrically connected to, coupled to, or electrically coupled to another element, it may be directly on, connected to, or coupled to the other element, or one or more intermediate elements may be present. In contrast, when an element is referred to as being directly on, directly connected to, or directly coupled to another element, no intermediate element is present. Although the terms "directly on," "directly connected to," or "directly coupled to" may not be used throughout the detailed description, elements shown as being directly on, directly connected to, or directly coupled to may be referred to in this way. As used herein, the singular form may include the plural form unless the context clearly indicates a particular case. Spatial relative terms (e.g., over, above, upper, under, beneath, below, lower, etc.) are intended to cover different orientations of the device in use or operation other than those illustrated in the figures. In some embodiments, the relative terms over and under may respectively include vertically above and vertically below. In some embodiments, the term adjacent may include laterally adjacent or horizontally adjacent. The various technical implementations described herein can be implemented (e.g., included in) digital electronic circuit systems, or in combinations thereof in computer hardware, firmware, or the like. Some implementations can be implemented using various semiconductor processing and / or packaging technologies. Some implementations can be implemented using various types of semiconductor processing technologies associated with semiconductor substrates (including, but not limited to, silicon (Si), gallium arsenide (GaAs), gallium nitride (GaN), silicon carbide (SiC), etc.). While certain features of the described embodiments have been depicted as described herein, those skilled in the art will readily conceive of many modifications, substitutions, alterations, and equivalents. Therefore, it should be understood that the accompanying claims are intended to cover all such modifications and alterations that fall within the scope of the embodiments. It should be understood that these are presented by way of example only and are not limiting, and various changes in form and detail are possible. Any part of the apparatus and / or method described herein can be combined in any combination, except for mutually exclusive combinations. The embodiments described herein may include various combinations and / or sub-combinations of the functions, components, and / or features of the different embodiments described. 100: Miniature Light Emitting Diode (LED) 110: Buffer Layer 115: Growth Interface Surface 120: Miniature Light Emitting Diode (LED) Platform 122: n-type Doped Layer 124: Active Region 126: p-type Doped Layer 128: p-type Doped Top Surface 130: Ag-based Junction 132: Reflector 140: Passivation Layer 200: Electronic Device 205: Impurity 220: Semiconductor Structure 230: Ag-based Junction 235: Metal Stack 240: Passivation Layer 300: Chart 350: Trace 360: Trace 430a: Pure Ag Junction 430b: Ag-based Junction 430c: Ag Substrate 430d :Ag base layer 430e1: First Ag layer 430e2: Second Ag layer 430f: Ag layer 435b: Metal stack 437c: Indium tin oxide (ITO) layer 438d: Thin Ni layer 438e: Thin Ni layer 440a: Passivation material 440b: Passivation layer 440c: Passivation layer 440d: Passivation layer 440e: Passivation layer 440f: Passivation layer 520a: Miniature light-emitting diode (LED) platform 520b: Miniature light-emitting diode (LED) platform 520c: Miniature light-emitting diode (LED) platform 520d: Miniature light-emitting diode LED Platform 520e: Miniature LED Platform 520f: Miniature LED Platform 530a: Ag-based p-type contact 530b1: p-type contact 530b2: p-type contact 530c1: p-type contact layer 530c2: Metal layer 530d1: p-type contact 530d2: Metal layer 530e1: p-type contact layer 530e2: Metal layer 530f: p-type contact 540a: Passivation layer 540b: Passivation layer 540c: Passivation layer 540d: Passivation layer 540e: Passivation layer 540f: Passivation layer 570: Substrate dielectric layer 600: Method 610: Block 620: Block 630: Block 640: Block 650: Block 700: Chart 750: Trace 760: Trace 800: Contact metal stack 828: Surface 830: Ag base contact 835a: Metal layer 835b: Metal layer 840: Passivation layer 870: Barrier layer 900: Contact metal stack 928: Surface 930: Ag base contact 935a: Metal layer 935b: Metal layer 940: Passivation layer 970: Barrier layer 1000: Miniature light-emitting diode (LED) 1010: Buffer layer; 1015: Growth interface surface; 1020: Micro LED platform; 1022: n-type doped layer; 1024: Active region; 1026: p-type doped layer; 1028: p-type doped top (upper) surface; 1030: Ag base junction; 1040: Absorption passivation layer; 1070: Barrier layer; 1100: Chart1150: Curve Fitting Data Set 1160: Curve Fitting Data Set Figure 1 is a diagram illustrating one example of a light-emitting diode (LED) device. Figure 2 illustrates one of the absorption functions of an example passivation layer. Figure 3 is a graph illustrating one of the experimental results, which demonstrate the improved stability and / or optical performance of a silver-based (Ag-based) junction in an exemplary LED with an absorbent passivation layer. Figures 4A to 4F are diagrams illustrating examples of Ag base junctions. Figures 5A to 5F illustrate exemplary LED devices that include a passivation layer that has been removed. Figure 6 is a flowchart illustrating one of the exemplary methods for generating an electronic device (such as a micro LED). Figure 7 is a graph illustrating one of the experimental results, which confirms the improved electrical stability of LEDs with a passivation layer removed. Figure 8 illustrates an example LED having an Ag base contact encapsulated by a barrier layer, wherein the contact layer of the LED is flat. Figure 9 illustrates an example LED having an Ag base contact encapsulated by a barrier layer, wherein the material surrounding the Ag base contact is non-planar and surrounds the Ag base contact. Figure 10 illustrates an example LED having an Ag base junction encapsulated by a barrier layer and passivated by impurity removal. Figure 11 is a chart illustrating one of the experimental data, the results of which confirm the improved performance associated with the use of a barrier layer. In drawings that are also drawn to scale, the same component symbols may indicate and / or similar components (elements, structures, etc.) in different views. The drawings typically illustrate, but are not intended to limit, the various embodiments discussed in this invention. Component symbols shown in a single drawing may not be repeated in related views for the same and / or similar elements. Component symbols repeated in multiple drawings may not be specifically discussed relative to the component symbols in those drawings, but rather provided for contextual information between related views. Furthermore, when multiple examples of a component are shown, not all identical components in the drawing are specifically referred to using a single component symbol. 100: Miniature Light Emitting Diode (LED) 110: Buffer layer 115: Growth interface surface 120: Miniature Light Emitting Diode (LED) Platform 122: n-type doped layer 124: Active Zone 126: p-type doped layer 128: p-type doped top surface 130: Ag base junction 132: Reflector 140: Passivation layer

Claims

1. An electronic device comprising: A semiconductor structure includes a doped surface; a silver-based (Ag-based) layer electrically contacting at least a portion of the doped surface, the Ag base layer having a specific contact resistance of 1e-2 ohm cm² or less with respect to the doped surface; and a passivation layer disposed on a portion of the semiconductor structure, a portion of the passivation layer being in solid contact with the Ag base layer, and the passivation layer comprising a material compound of a group II nitride material.

2. The electronic device of claim 1, wherein the doped surface is at least one of: a top surface of the semiconductor structure; or a surface of an epitaxial layer.

3. The electronic device as claimed in claim 1, wherein: The semiconductor structure includes a sidewall surface; and at least a portion of the passivation layer is disposed on the sidewall surface.

4. The electronic device as claimed in claim 1, wherein: The first part of the Ag base layer is disposed on the doped surface; and the second part of the Ag base layer is disposed on the passivation layer.

5. The electronic device of claim 1, wherein the electronic device has a lateral dimension of less than or equal to 10 micrometers (μm).

6. The electronic device of claim 1, wherein the semiconductor structure comprises a group III nitride material.

7. The electronic device of claim 1, wherein the group II nitride material comprises at least one of the following: magnesium nitride, calcium nitride, or beryllium nitride.

8. The electronic device of claim 1, wherein the material compound further comprises a group III element.

9. The electronic device of claim 1, wherein the passivation layer comprises at least 90 percent of the group II nitride material as a percentage of the composition.

10. The electronic device of claim 1, wherein the semiconductor structure comprises: a layer comprising gallium nitride (GaN); and a light-emitting layer comprising indium gallium nitride (InGaN).

11. The electronic device of claim 10, wherein the electronic device is a light-emitting diode (LED).

12. The electronic device of claim 11, wherein the LED includes a platform having a top surface, a sidewall and a substrate, and the passivation layer covers a portion of the top surface and a portion of the sidewall.

13. The electronic device of claim 1, wherein for light having a wavelength in the range of 450 to 650 nanometers (nm), an interface between the Ag substrate and the doped surface has a reflectivity greater than 90 percent.

14. The electronic device of claim 1, wherein the passivation layer has a refractive index greater than 1.7 for light having a wavelength in the range of 450 to 650 nanometers (nm).

15. The electronic device of claim 1, wherein the passivation layer is configured to absorb at least one of oxygen or hydrogen.

16. The electronic device of claim 1, wherein the passivation layer is configured to trap mobile charges.

17. A miniature light-emitting diode (miniature LED), comprising: A semiconductor structure having: a doped surface; and a luminous area; A metal substrate electrically contacts at least a portion of the doped surface, the metal substrate having a specific contact resistance of 1e-2 ohm cm2 or less to the doped surface; and a passivation layer disposed on the semiconductor structure, a portion of the passivation layer being in solid contact with the metal substrate, the passivation layer comprising a compound of a group II nitride material, and the microLED having a lateral dimension of less than or equal to 10 micrometers (μm).

18. The micro LED of claim 17, wherein the semiconductor structure comprises a group III nitride material.

19. The micro LED of claim 17, wherein the group II nitride material comprises at least one of the following: magnesium nitride, calcium nitride, or beryllium nitride.

20. The micro LED of claim 17, wherein the compound further comprises a group III element.

21. The micro LED of claim 17, wherein the passivation layer comprises at least 90 percent of the group II nitride material based on the composition.

22. The microLED of claim 17, wherein for light having a wavelength in the range of 450 to 650 nanometers (nm), the interface between the metal substrate and the doped surface has a reflectivity greater than 90 percent.

23. The micro LED of claim 17, wherein the passivation layer is configured to: absorb at least one of oxygen or hydrogen; and trap mobile charges.

24. An LED comprising: A semiconductor structure includes a doped surface and a light-emitting region; a silver-based (Ag-based) layer electrically contacting at least a portion of the doped surface, the Ag base layer having a specific contact resistance of 1e-2 ohm cm² or less with respect to the doped surface; and a passivation layer formed on a surface of the semiconductor structure, a portion of the passivation layer being in solid contact with the Ag base layer, and the passivation layer containing a chemical element X having a formation enthalpy of oxide XO greater than 500 kJ / mol.

25. The LED of claim 24, wherein the passivation layer comprises a compound of X and nitrogen.

26. The LED of request item 24, wherein the elements are of group X-II.

27. The LED of claim 24, wherein the passivation layer further comprises a group III element.

28. The LED of claim 24, wherein the passivation layer comprises at least 10 percent X based on the composition.

29. The LED of claim 24, wherein for light having a wavelength in the range of 450 to 650 nanometers (nm), the interface between the Ag substrate and the doped surface has a reflectivity greater than 90 percent.

30. The LED of claim 24, wherein the passivation layer has a refractive index greater than 1.7 for light having a wavelength in the range of 450 to 650 nanometers (nm).

31. The LED of claim 24, wherein the passivation layer: adsorbs at least one of oxygen or hydrogen; and traps mobile charges.

32. A method for producing a light-emitting diode (LED), the method comprising: A silver-based (Ag-based) layer is formed on a doped surface of a semiconductor structure containing a light-emitting region. The Ag-based layer is electrically in contact with the doped surface and has a specific contact resistance of 1e-2 ohm cm² or less to the doped surface. A dielectric layer is formed on the semiconductor structure, close to the Ag-based layer. After the formation of the Ag-based layer and the dielectric layer, a heat treatment operation is performed on the semiconductor structure, and the dielectric layer is configured to maintain a reflectivity of the Ag-based layer greater than or equal to 80% for light at a wavelength of 500 nm after the heat treatment operation.

33. A method of operating a light-emitting diode (LED) having: a semiconductor structure having a doped surface and a light-emitting region; a silver-based (Ag-based) layer electrically contacting at least a portion of the doped surface, the Ag-based layer having a specific contact resistance of 1e-2 ohm cm² or less with respect to the doped surface; and a dielectric passivation layer comprising a group II nitride material formed on a surface of the semiconductor structure, wherein a portion of the dielectric passivation layer is in solid contact with the Ag-based layer, the method comprising: The LED is operated using an electric current, causing one of the light-emitting regions of the LED to emit light, and the dielectric passivation layer is configured to promote stable operation of the LED during this operation.

34. A method for producing a light-emitting diode (LED), the method comprising: A semiconductor LED platform is formed; a protective layer is formed on the semiconductor LED platform; A metal contact is formed on a p-type surface of the semiconductor LED platform, the metal contact having a specific contact resistance of 1e-2 ohm cm2 or less to the p-type surface; and a processing operation is performed on the LED, the processing operation causing the release of a species, the protective layer being configured to reduce the diffusion of the species toward the semiconductor LED platform.

35. A light-emitting diode (LED) comprising: A semiconductor platform having: an n-type doped region; an active region; and a p-type doped region terminated by a p-type surface; and a p-type contact disposed on a portion of the p-type surface, the p-type contact comprising: an Ag substrate electrically contacting the p-type surface, the Ag substrate having a specific contact resistance of 1e-2 ohm cm2 or less to the p-type surface; and a metal stack encapsulating the Ag substrate, the metal stack comprising at least one layer of a conductive compound containing a metal and nitrogen.

36. A light-emitting diode (LED) comprising: A semiconductor platform comprising: an n-type doped region; and a light-emitting region; A p-type doped region terminated by a p-type surface; and at least one sidewall; a p-type contact formed on a portion of the p-type surface, the p-type contact comprising at least one layer of a conductive compound containing a first metal and nitrogen, the p-type contact having a specific contact resistance of 1e-2 ohm cm2 or less to the p-type surface; and a passivation layer formed on a portion of the at least one sidewall, the passivation layer comprising at least one layer of an insulating compound including a second metal and nitrogen.

37. A method for generating an LED, comprising: A p-type contact is formed that is in direct contact with a p-type surface of an LED semiconductor platform, the p-type contact having a specific contact resistance of 1e-2 ohm cm2 or less with respect to the p-type surface; a metal stack is formed on the p-type contact, the metal stack having a conductive barrier layer; and a processing operation is performed on the LED, the processing operation using or causing a release of hydrogen, the conductive barrier layer being configured to reduce the diffusion of hydrogen through the p-type contact to the p-type surface during the processing operation.

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