Techniques in accordance with embodiments described herein are directed to semiconductor devices including a layer of aluminum nitride AlN or aluminum gallium nitride AlGaN as a ferroelectric layer and a method of making a thin film of AlN/AlGaN that possesses ferroelectric properties. In a ferroelectric transistor, a thin film of AlN/AlGaN that exhibits ferroelectric properties is formed between a gate electrode and a second semiconductor layer, e.g., of GaN.