On the Performance Limits of Cryogenically Operated SiGe HBTs and Its Relation to Scaling for Terahertz Speeds
On the Performance Limits of Cryogenically Operated SiGe HBTs and Its Relation to Scaling for Terahertz Speeds
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DOI：
10.1109/ted.2009.2016017
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发表时间：
2009-03
影响因子：
3.1
通讯作者：
Jiahui Yuan;John D. Cressler;R. Krithivasan;T. Thrivikraman;M. Khater;D. Ahlgren;Alvin J. Joseph;J. Rieh
中科院分区：
文献类型：
--
作者：
Jiahui Yuan;John D. Cressler;R. Krithivasan;T. Thrivikraman;M. Khater;D. Ahlgren;Alvin J. Joseph;J. Rieh
在硅材料系统内实现太赫兹（THz）晶体管的目标最近引起了极大的兴趣。在本文中，我们使用工作温度作为一种有效的方式，获得更好地了解SiGe HBT的性能限制和实现太赫兹速度的最终能力。不同的垂直剖面缩放和减少寄生效应的方法进行了讨论，和三个原型第四代SiGe HBT进行了比较和评估，深低温温度下，使用直流和交流测量。使用130 nm光刻在4.5 K下实现了463/618 GHz的创纪录峰值fT/fmax（300 K下为309/343 GHz），证明了在硅基晶体管中同时达到半THz fT和fmax的可行性。该冷却SiGe HBT的BVCEO在4.5 K时为1.6 V（BVCBO = 5.6 V），产生了创纪录的750 GHzIdrV（300 K时为510 GHzIdrV）的fT乘以BVCEO乘积。这些显着水平的晶体管性能和相关的有趣的设备物理在低温下观察到这些设备提供了重要的见解，在室温下的THz速度的进一步设备缩放。据预测，在一个新的缩放路线图，室温SiGe HBT的fT/fmax可能达到782/910 GHz的BVCEO为1.1 V的32纳米光刻节点。
The goal of achieving terahertz (THz) transistors within the silicon material system has generated significant recent interest. In this paper, we use operating temperature as an effective way of gaining a better understanding of the performance limits of SiGe HBTs and their ultimate capabilities for achieving THz speeds. Different approaches for vertical profile scaling and reduction of parasitics are addressed, and three prototype fourth-generation SiGe HBTs are compared and evaluated down to deep cryogenic temperatures, using both dc and ac measurements. A record peak fT/fmax of 463/618 GHz was achieved at 4.5 K using 130-nm lithography (309/343 GHz at 300 K), demonstrating the feasibility of reaching half-THz fT and fmax simultaneously in a silicon-based transistor. The BVCEO of this cooled SiGe HBT was 1.6 V at 4.5 K (BVCBO = 5.6 V), yielding a record fT times BVCEO product of 750 GHzldrV (510 GHzldrV at 300 K). These remarkable levels of transistor performance and the associated interesting device physics observed at cryogenic temperatures in these devices provide important insights into further device scaling for THz speeds at room temperature. It is predicted in a new scaling roadmap that fT/fmax of room-temperature SiGe HBTs could potentially achieve 782/910 GHz at a BVCEO of 1.1 V at the 32-nm lithographic node.