美国半导体厂商TowerJazz和美国国防部下属高级研究项目局（DARPA）最近达成了一项共同出资开发频率高达500GHz的SiGe异质结双极晶体管(HBT)项目。这一项目将采用光栅掩模但利用传统的光刻技术。这一技术组合有望以较低的成本获得非常高的光刻精度，从而绕过采用浸没式光刻带来的成本问题。

TowerJazz and DARPA unite to advance SiGe HBT development

The “GRATE” multiyear program will develop up to 500GHz devices and employ the use of grating masks combined with conventional photolithography.

Jazz Semiconductor, a fully owned U.S. subsidiary of Tower Semiconductor (operating collectively under the brand name, TowerJazz), has formed a cost-sharing collaboration with DARPA to advance its roadmap for high frequency SiGe HBT devices.

The DARPA program named “GRATE” (Gratings of Regular Arrays and Trim Exposures), will employ the use of grating masks combined with conventional photolithography to achieve very fine dimension features as an alternative to more costly lithography techniques such as immersion lithography. The grating masks will be used in combination with the standard masks used today in volume semiconductor device manufacturing.

The TowerJazz roadmap includes BiCMOS platforms which have both CMOS and BiPolar devices on a single wafer and are offered monthly in multi-project wafer (MPW) runs. The existing BiCMOS platforms are based on 350nm, 180nm and 130nm CMOS nodes, and the variants include HBT device performance at 60, 150, 200 and recently 260GHz.

In the multi-year GRATE program, TowerJazz will develop methods for implementing grating and trim exposures in its existing BiCMOS platforms in three stages: to target 200-300GHz devices, 300-400GHz devices and finally with research on 400-500GHz HBT devices.

TowerJazz has partnered with the University of California, San Diego (UCSD) for novel circuit demonstrations using the new technology platforms and for teaming on extremely high frequency test and characterization of HBT devices as well as interconnect and passive components such as microstrip lines and MIM capacitors. This high frequency data and modelling will be the basis for mmWave design kits that enable customers to design and simulate mmWave circuits and products.

In addition, TowerJazz will bring its pure-play specialty wafer foundry approach to the program through MPW runs to allow select, early access to the technology.

“It is exciting to work with DARPA on the use of gratings and trim exposures. Our team has demonstrated abilities to print sub-90nm features with very good depth of focus, and we are applying these methods to our SiGe BiCMOS technologies. We look forward to demonstrating novel capabilities and offering these technologies to our customers through our MPW infrastructure,” said David Howard, TowerJazz Executive Director and Primary Investigator for GRATE.