Cai Jun, Wu Peng, Tripathi Rahul, Kong Jing, Chen Zhihong, Appenzeller Joerg
Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States.
Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States.
ACS Nano. 2024 Aug 27;18(34):23489-23496. doi: 10.1021/acsnano.4c07024. Epub 2024 Aug 13.
Ternary content-addressable memory (TCAM) is promising for data-intensive artificial intelligence applications due to its large-scale parallel in-memory computing capabilities. However, it is still challenging to build a reliable TCAM cell from a single circuit component. Here, we demonstrate a single transistor TCAM based on a floating-gate two-dimensional (2D) ambipolar MoTe field-effect transistor with graphene contacts. Our bottom graphene contacts scheme enables gate modulation of the contact Schottky barrier heights, facilitating carrier injection for both electrons and holes. The 2D nature of our channel and contact materials provides device scaling potentials beyond silicon. By integration with a floating-gate stack, a highly reliable nonvolatile memory is achieved. Our TCAM cell exhibits a resistance ratio larger than 1000 and symmetrical complementary states, allowing the implementation of large-scale TCAM arrays. Finally, we show through circuit simulations that in-memory Hamming distance computation is readily achievable based on our TCAM with array sizes up to 128 cells.
三态内容可寻址存储器(TCAM)因其大规模并行内存计算能力,在数据密集型人工智能应用中颇具前景。然而,用单个电路元件构建可靠的TCAM单元仍具有挑战性。在此,我们展示了一种基于具有石墨烯触点的浮栅二维(2D)双极型碲化钼(MoTe)场效应晶体管的单晶体管TCAM。我们的底部石墨烯触点方案能够对触点肖特基势垒高度进行栅极调制,有利于电子和空穴的载流子注入。我们的沟道和触点材料的二维特性为超越硅的器件缩放提供了潜力。通过与浮栅堆栈集成,实现了高度可靠的非易失性存储器。我们的TCAM单元呈现出大于1000的电阻比和对称互补状态,可实现大规模TCAM阵列。最后,我们通过电路模拟表明,基于我们的TCAM,内存汉明距离计算对于高达128个单元的阵列大小很容易实现。