Thermal effects in suspended RF spiral inductors

Author

Sagkol, H. ; Sinaga, S. ; Burghartz, J.N. ; Rejaei, B. ; Akhnoukh, A.

Author_Institution

Dept. of Electr. Eng., Delft Univ. of Technol., Netherlands

Volume

26

Issue

8

fYear

2005

Firstpage

541

Lastpage

543

Abstract

Self-heating effects on integrated suspended and bulk spiral inductors are explored. A dc current is fed through the inductors during measurement to emulate dc and radio frequency power loss on the inductor. A considerable drop in Q by /spl sim/18% at 36.5 mW is observed for suspended coils with 3-μm aluminum metallization compared to reference inductors on bulk-Si. Simulations in Ansoft´s ePhysics indicate that, due to the thermal isolation of the suspended coil, the power loss from resistive self-heating in the metal has to be transferred outwards through the metal turns. This also results in a thermal time constant. This time constant is measured to be /spl sim/10 ms, meaning that it can affect power circuits operating in pulsed mode.

Keywords

Q-factor; S-parameters; inductors; radiofrequency integrated circuits; 10 ms; 3 micron; Ansoft ePhysics; aluminum metallization; bulk spiral inductors; dc power loss; integrated suspended inductors; micromachining; quality factor; radio frequency power loss; resistive self-heating; self-heating effects; small-signal S-parameter measurements; suspended RF spiral inductors; suspended coil; thermal effects; thermal isolation; thermal time constant; Aluminum; Coils; Current measurement; Frequency measurement; Inductors; Loss measurement; Power measurement; Pulse measurements; Radio frequency; Spirals; Micromachining; radio frequency (RF) circuits; spiral inductor; suspended inductor; thermal effects;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/LED.2005.852524

Filename

1468216