Novel technologies for the realisation of GaAs pHEMTs with 120 nm self-aligned and nanoimprinted T-gates

Moran, D., Boyd, E., McLelland, H., Elgaid, K., Chen, Y., Macintyre, D.S., Thoms, S., Stanley, C.R. and Thayne, I.G. (2003) Novel technologies for the realisation of GaAs pHEMTs with 120 nm self-aligned and nanoimprinted T-gates. Microelectronic Engineering, 67-89, pp. 769-774. (doi: 10.1016/S0167-9317(03)00137-0)

Abstract

To address the major issues of increasing device frequency performance and reducing fabrication costs of 100 nm scale gate length III–V HEMT devices, two novel technologies developed for GaAs pHEMT are reported, namely: (i) A low resistance, non-annealed Ohmic contact technology based on a thin metallisation and highly doped In_0.2GaAs/GaAs cap layer which is compatible with a self-aligned gate process. (ii) A succinic acid based gate recess etch which selectively etches the In_0.2GaAs/GaAs cap required for the non-annealed ohmic contact technology, stopping on a 5-nm Al_0.3GaAs etch stop layer. Incorporating both of these processes, self-aligned T-gate and nanoimprinted T-gate devices have been realised. Completed self-aligned T-gate GaAs pHEMT devices of 120 nm gate length exhibited an f_T and f_max of 135 and 180 GHz, respectively, while nanoimprint 120 nm GaAs pHEMT devices demonstrated excellent DC characteristics, including a transconductance of 450 mS/mm.

• Item Type: Articles
• Keywords: GaAs pHEMT, Nanoimprint, Ohmic contact, Self-aligned, Succinic acid.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Thoms, Dr Stephen and Thayne, Prof Iain and Stanley, Professor Colin and Macintyre, Dr Douglas and Moran, Professor David and Elgaid, Dr Khaled
• Authors: Moran, D., Boyd, E., McLelland, H., Elgaid, K., Chen, Y., Macintyre, D.S., Thoms, S., Stanley, C.R., and Thayne, I.G.
• Subjects: T Technology > TK Electrical engineering. Electronics Nuclear engineering
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering; University Centres > Glasgow Materials Research Initiative
• Journal Name: Microelectronic Engineering
• ISSN: 0167-9317