Cu-Doped TiNxOy Thin Film Resistors DC/RF Performance and Reliability

Abstract

We fabricated Cu-doped TiNxOy thin film resistors by using atomic layer deposition, optical lithography, dry etching, Ti/Cu/Ti/Au e-beam evaporation and lift-off processes. The results of the measurements of the resistance temperature dependence, non-linearity, S-parameters at 0.01–26 GHz and details of the breakdown mechanism under high-voltage stress are reported. The devices’ sheet resistance is 220 ± 8 Ω/□ (480 ± 20 µΩ*cm); intrinsic resistance temperature coefficient (TCR) is ~400 ppm/°C in the T-range of 10–300 K; and S-parameters versus frequency are flat up to 2 GHz with maximum variation of 10% at 26 GHz. The resistors can sustain power and current densities up to ~5 kW*cm−2 and ~2 MA*cm−2, above which they switch to high-resistance state with the sheet resistance equal to ~200 kΩ/□ (~0.4 Ω*cm) caused by nitrogen and copper desorption from TiNxOy film. The Cu/Ti/TiNxOy contact is prone to ageing due to gradual titanium oxidation while the TiNxOy resistor body is stable. The resistors have strong potential for applications in high-frequency integrated and hybrid circuits that require small-footprint, medium-range resistors of 0.05–10 kΩ, with small TCR and high-power handling capability.

Тонкие Пленки Оксинитрида Титана Для Сенсоров Широкого Диапазона Температур

“…Тело сенсора выполнено из низкоомной пленки G2 TiN 0.87 O 0.97 толщиной 40 nm, осажденной на ситалл. Технологический процесс получения данной структуры был описан ранее для резистивных элементов на основе пленки G1 TiN 0.82 O 1.43[14].Активная область (тело) сенсора была сформирована из пленки TiN 0.87 O 0.97 с помощью оптической литографии на установке EVG 610 с последующим плазменным травлением в установке RIE-1701 Nordson MARCH в газовой смеси CF 4 (2.5 • 10 −7 m 3 • s −1 )/O 2 (5 • 10 −8 m 3 • s −1 ) при высокочастотной мощности 250 W и давлении 33 Pa в течение 120 s. Электрические контакты и разводка сенсора были Температурная зависимость сопротивления и микрофотография (на вставке) сенсора на основе пленки TiN 0.87 O 0.97 толщиной 40 nm. сформированы вторым слоем с помощью совмещенной оптической литографии с использованием негативного фоторезиста AZ nLOF-2035 и электронно-лучевого напыления Ni (5 nm)/Cu (1 µm)/Ni (5 nm)/Au (50 nm) с последующим взрывным снятием фоторезиста в ацетоне.…”

Titanium Oxynitride Thin Films Wide Temperature Range Sensors

“…The body of this sensor was formed from a low-resistivity G2 TiN 0.87 O 0.97 film with a thickness of 40 nm deposited onto sitall. The process of fabrication of this structure has been illustrated earlier through an example of resistive elements based on a G1 TiN 0.82 O 1.43 film [14]. The active region (body) of the sensor was formed from a TiN 0.87 O 0.97 film by optical lithography in an EVG 610 setup with subsequent plasma etching in a RIE-1701 Nordson MARCH system in a CF 4 (2.5 • 10 −7 m 3 • s −1 )/O 2 (5 • 10 −8 m 3 • s −1 ) gas mixture at a high-frequency power of 250 W and a pressure 33 Pa for 120 s. Electric contacts and interconnections were formed as a second overlapping layer by optical lithography with the use of an AZ nLOF-2035 negative photoresist and electron beam deposition of Ni (5 nm)/Cu (1 µm)/Ni (5 nm)/Au (50 nm) with subsequent lift-off stripping in acetone.…”