SiC substrates are in demand for high power applications such as electric vehicles, solar panels, and industrial electronics. A physical vapor transport (PVT) apparatus for growth of silicon carbide (SiC) ingots can be improved by adding moveable heaters. The heaters can be either inductive or resistive. By tightly controlling temperature gradients during the growth phase, and by adding an in-situ anneal following the growth phase, the resulting SiC crystal can be taller, with fewer defects, and can be less likely to crack during subsequent grinding or polishing operations.

A silicon carbide wafer having a seed end and a dome end opposite to the seed end. In the silicon carbide wafer, a basal plane dislocation (BPD) density detected by potassium hydroxide (KOH) etching is less than 550 pcs/cm.sup.2 at both the seed end and the dome end, and a basal plane dislocation (PL-BPD) density detected by photoluminescence is less than 2000 pcs/cm.sup.2 at both the seed end and the dome end.

SiC substrates are in demand for high power applications such as electric vehicles, solar panels, and industrial electronics. A physical vapor transport (PVT) apparatus for growth of silicon carbide (SiC) ingots can be improved by incorporating a moveable source. During growth of the ingot, the shape of the growth interface can be maintained as a convex shape by keeping a substantially constant distance between the growth interface and the source material. It is shown that temperature gradients during the growth phase are also influenced by the shape of the growth interface. By moving the source during crystal growth, the resulting SiC ingot can be taller with fewer defects, and can be less likely to crack during subsequent grinding or polishing operations.

A crystal growing method for crystals include the following steps. A first crystal seed is provided, the first crystal seed has a first monocrystalline proportion and a first size. N times of crystal growth processes are performed on the first crystal seed, wherein each of the crystal growth process will increase the monocrystalline proportion, and the N times of crystal growth processes are performed until a second crystal having a monocrystalline proportion of 100% is reached, and wherein the N times includes more than 3 times of crystal growth processes. Each crystal growth process includes adjusting a ratio difference (Tz/Tx) between an axial temperature gradient (Tz) and a radial temperature gradient (Tx) of the crystal, so as to control the ratio difference within a range of 0.5 to 3 for forming the second crystal.

A method of conditioning MoCl.sub.5 comprises heating a container of MoCl.sub.5 to a temperature ranging from approximately 140 C. to 190 C. for a period ranging from approximately 2 hours to approximately 100 hours to produce a MoCl.sub.5-containing composition comprising approximately 10% weight to approximately 60% weight of Phase 1 MoCl.sub.5 and 90% weight to approximately 40% weight of Phase 2 MoCl.sub.5 as determined by X-ray diffraction. This MoCl.sub.5-containing composition is expected to be more thermally stable and provides stable vapor supply.

A method for growing a linearly graded germanium-tin film using molecular beam epitaxy (MBE) includes providing a substrate in a molecular beam epitaxy (MBE) chamber; establishing a constant germanium beam equivalent pressure (BEP); applying a logarithmic-based algorithm to dynamically control a tin (Sn) effusion cell temperature to achieve a linear increase in tin (Sn) beam equivalent pressure (BEP) over time; and dynamically adjusting the tin (Sn) effusion cell temperature for growing a linear graded germanium-tin (Ge1-xSnx) film having a linear tin (Sn) composition gradient. The methodology applies to any element or molecule delivered via thermal evaporation, electron-beam evaporation, or vapor-phase methods. For gaseous precursors in CVD systems, flow may be modulated using mass flow controllers or valve adjustments. The approach enables growth of various materials/alloys on substrates including germanium, silicon, sapphire, indium arsenide, indium gallium arsenide, and silicon carbide to name a few.

Disclosed herein are a method, a system, and a device for controlling a crystal growth device. The method includes: obtaining historical growth data of at least one crystal growth device, the historical growth data including historical growth control data and historical growth result data; and determining a control mode of a target crystal growth device based on the historical growth data and a target growth result, the control mode including at least one of a temperature control mode and a power control mode.

A silicon carbide crystal and a silicon carbide wafer, wherein a monocrystalline proportion of the silicon carbide crystal and the silicon carbide wafer is 100%, the resistivity thereof is in a range of 15 m.Math.cm to 20 m.Math.cm, and a deviation of an uniformity of the resistivity thereof is less than 0.4%.

Provided are a silicon carbide crystal growth device and a quality control method. The device includes: an annealing unit, a crystal growth unit, an atmosphere control unit, and a transport system; the atmosphere control unit provides a gas environment with low water, oxygen and nitrogen; the transport system transports a plurality of target objects after high-temperature purification by the annealing unit to the atmosphere control unit; after assembling silicon carbide seed crystal and silicon carbide powder in a graphite crucible and covering with thermal insulation material to form a container inside the atmosphere control unit, the transport system transports the container to the crystal growth unit. The method uses a weighing system in a chamber of the crystal growth unit to detect a weight change of silicon carbide seed crystal and silicon carbide powder during a crystal growth process through a plurality of weight sensors of the weighing system.

A silicon carbide wafer and a method of fabricating the same are provided. In the silicon carbide wafer, a ratio (V:N) of a vanadium concentration to a nitrogen concentration is in a range of 2:1 to 10:1, and a portion of the silicon carbide wafer having a resistivity greater than 10.sup.12 .Math.cm accounts for more than 85% of an entire wafer area of the silicon carbide wafer.