Microwave characteristics of advanced MIM capacitors for MMICs using ultra-thin remote-PECVD Si ₃N ₄ dielectric layers

We have fabricated metal-insulator-metal (MIM) capacitors with ultra-thin (200 Å) remote-PECVD Si ₃N ₄ dielectric layers of excellent electrical properties and performed on-wafer RF measurements. The size of MIM capacitor was successfully reduced by 90% compared with that of conventional MIM capacitor with 2,000 Å PECVD Si ₃N ₄ dielectric layer. The breakdown field strength of 200 Å MIM capacitors was larger than 3.5 MV/cm which indicates the excellent quality of the film. The main capacitance per unit area extracted by RF measurements was as high as 2,900 pF/mm ². Despite ultra-thin dielectric films of 200 Å, the fabricated MIM capacitors show good RF performance and have high yield.