Surface Ligand Removal in Atomic Layer Deposition of GaN Using Triethylgallium

Gallium nitride (GaN) is one of the most important semiconductor materials in modern electronics. While GaN films are routinely deposited by chemical vapor deposition at around 1000 °C, low-temperature routes for GaN deposition need to be better understood. Herein, we present an atomic layer deposition (ALD) process for GaN-based on triethyl gallium (TEG) and ammonia plasma and show that the process can be improved by adding a reactive pulse between the TEG and ammonia plasma, making it an ABC-type pulsed process. We show that the material quality of the deposited GaN is not affected by the B-pulse, but that the film growth per ALD cycle increase when a B-pulse is added. We suggest that this can be explained by removal of ethyl ligands from the surface by the B-pulse, enabling a more efficient nitridation by the ammonia plasma. We show that the B-pulsing can be used to enable GaN deposition with a thermal ammonia pulse, albeit of X-ray amorphous films.

Surface Ligand Removal in Atomic Layer Deposition of GaN Using Triethylgallium

Gallium nitride (GaN) is one of the most important semiconductor materials in modern electronics. While GaN films are routinely deposited by chemical vapor deposition at around 1000 °C, low-temperature routes for GaN deposition need to be better understood. Herein, we present an atomic layer deposition (ALD) process for GaN-based on triethyl gallium (TEG) and ammonia plasma and show that the process can be improved by adding a reactive pulse between the TEG and ammonia plasma, making it an ABC-type pulsed process. We show that the material quality of the deposited GaN is not affected by the B-pulse, but that the film growth per ALD cycle increase when a B-pulse is added. We suggest that this can be explained by removal of ethyl ligands from the surface by the B-pulse, enabling a more efficient nitridation by the ammonia plasma. We show that the B-pulsing can be used to enable GaN deposition with a thermal ammonia pulse, albeit of X-ray amorphous films.

Crucial role of reactive pulse-gas on a sputtered Zn3N2 thin film formation

Herein, we demonstrate a powerful technique, known as reactive gas-timing (RGT) rf magnetron sputtering, to fabricate high quality Zn3N2 thin films at room temperature without applying any additional energy sources.

Fabrication of Aluminum Nitride Films by Reactive Pulse DC Magnetron Sputtering for Vibration Energy Harvester

Aluminum nitride (AlN) film as a piezoelectric material has been used widely, particularly in vibration energy harvester due to its unique and enhanced properties such as high temperature resistance and compatibility with CMOS processes. In this work, AlN film with (002) preferred orientation was prepared on silicon wafers by pulse DC reactive magnetron sputtering (RMS), and the properties such as peak intensity, full width at half maximum (FWHM) and surface morphology were investigated by x-ray diffraction (XRD) and scanning electron microscopy (SEM). The preferred orientation was found to be sensitive to deposition conditions such as gas flow rate, power, bottom electrodes materials and substrates temperature. The results shows that the intensity was 1.1×105 counts, the FWHM was 1.9owhen the temperature was 260°C. The film was used to fabricate the vibrated energy harvester successful and the power density reached about 3000uW/cm3 at the vibration frequency under 1g acceleration.

Structure and Optical Property of Cu2O:N Thin Film Deposited by Reactive Pulse Magnetron Sputtering

N-doped Cu2O (Cu2O:N) thin films were deposited on glass substrate by reactive pulse magnetron sputtering method using Cu target. Crystalline phases of thin films were controlled by adjusting N2/ O2flow rate ratio and sputtering power precisely during the sputtering process, and the single phase of Cu2O(111) thin films were obtained at room temperature. The thin films deposited at different sputtering powers were characteristics of 2D growth and the root mean square (RMS) of surface roughness of thin films gradually increased with the increasing of sputtering power. The optical band gap (Eg) of thin films were in the range 2.18-2.35 eV, and slightly decreased with increasing of sputtering power from 45 W to 90 W.

Effects of Substrate Temperature on Structure and Optical Property of Cu2O:N Thin Film Deposited by Reactive Pulse Magnetron Sputtering

N-doped Cu2O (Cu2O:N) thin films were deposited on glass substrate by reactive pulse magnetron sputtering method using Cu target in a mixture of N2、O2and Ar atmosphere. Effect of substrate temperature on structure, surface morphology and optical properties of thin films were investigated by XRD, AFM and UV-Vis spectroscopy. The results showed that the single-phase of Cu2O(111) thin films were grown for substrate temperature < 200°C. The thin films deposited under different substrate temperatures are characteristics of 2D growth. Moreover,the optical band gap Egof thin film was in the range 2.54-2.58eV, and slightly decreased with increasing of substrate temperatures from RT to 400°C.

Preparation and Biocompatibility of Tantalum Oxide Films Containing the Hydroxyl Group

Amorphous Ta-O films were synthesized by reactive pulse unbalanced magnetron sputtering system in this paper. Then the well-crystallized Ta-O films were obtained after they were annealed in vacuum at 800°C for 1h. Hydroxyl group on the surface of amorphous tantalum oxide films was prepared by plasma hydrogenation method. The phase structure was investigated by X-ray diffraction (XRD). The hydroxyl group was characterized using Fourier transform infrared spectroscopy (FTIR). The morphology and growth behavior of the vitro platelet adhesion on the as-deposited, annealed and plasma hydrogenated Ta-O films were analyzed through scanning electron microscope (SEM). The results showed that the quantity of platelet adhered onto the annealed surface were less than as-deposited and hydrogenised films. A new method of preparing hydroxyl group without coupling agents on the inorganic biomaterials has been studied by plasma hydrogenation.