US 12,216,077 B2
BioFET device having a metal crown structure as a sensing layer disposed on an oxide layer formed under a channel region of a transistor
Chun-Wen Cheng, Zhubei (TW); Yi-Shao Liu, Zhubei (TW); and Fei-Lung Lai, New Taipei (TW)
Assigned to Taiwan Semiconductor Manufacturing Co., Ltd., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Co., Ltd., Hsinchu (TW)
Filed on Nov. 2, 2020, as Appl. No. 17/087,112.
Application 16/021,077 is a division of application No. 13/969,160, filed on Aug. 16, 2013, abandoned.
Application 17/087,112 is a continuation of application No. 16/021,077, filed on Jun. 28, 2018, granted, now 10,823,696.
Claims priority of provisional application 61/782,534, filed on Mar. 14, 2013.
Prior Publication US 2021/0072181 A1, Mar. 11, 2021
Int. Cl. H01L 29/78 (2006.01); G01N 27/414 (2006.01); H01L 23/34 (2006.01); H01L 29/66 (2006.01); H01L 21/84 (2006.01)
CPC G01N 27/4145 (2013.01) [H01L 23/345 (2013.01); H01L 29/66477 (2013.01); H01L 29/78 (2013.01); H01L 21/84 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A biological field-effect transistor (BioFET) device, comprising:
a substrate comprising a semiconductor layer;
a transistor comprising a gate structure disposed on a front side of the semiconductor layer and a channel region disposed between source and drain regions that are disposed within the semiconductor layer;
first and second doped regions comprising dopants of a conductivity type that is different from dopants in the source and drain regions,
wherein the source region comprises a first vertical inner sidewall in contact with the channel region and a first vertical outer sidewall in contact with the first doped region, and
wherein the drain region comprises a second vertical inner sidewall in contact with the channel region and a second vertical outer sidewall in contact with the second doped region;
a multi-layer interconnect (MLI) structure disposed on the front side of the semiconductor layer and comprising an inter-metal dielectric layer and a conductive line;
a dielectric layer comprising a first portion disposed on a first surface plane and a second portion disposed on a second surface plane different from the first surface plane,
wherein the first portion of the dielectric layer is in contact with back-side surfaces of the source and drain regions and the first and second doped regions, and
wherein the second portion of the dielectric layer extends into the semiconductor layer and into the inter-metal dielectric layer and is in contact with the conductive line and a sidewall of the semiconductor layer;
an interface layer comprising a high-k dielectric layer disposed within an opening of the dielectric layer; and
a metal crown structure disposed on the dielectric layer and the interface layer, wherein a first portion of the metal crown structure is in contact with a top surface of the dielectric layer, a second portion of the metal crown structure is disposed on a side surface of the dielectric layer, and a third portion of the metal crown structure is disposed on the interface layer.
 
11. A biological field-effect transistor (BioFET) device, comprising:
a substrate comprising a semiconductor layer;
a first dielectric layer disposed on a front side of the semiconductor layer;
a conductive line disposed in the first dielectric layer;
a second dielectric layer comprising a silicon oxide layer disposed on a back side of the semiconductor layer, wherein the second dielectric layer extends into the semiconductor layer and into the first dielectric layer and is in contact with the conductive line; and
an array of transistors, wherein each transistor of the array of transistors comprises:
a gate structure disposed on the front side of the semiconductor layer and
a channel region disposed between and in contact with vertical inner sidewalls of source and drain regions that are disposed within the semiconductor layer, wherein the source and drain regions are in contact with a bottom surface of the second dielectric layer;
a first doped region disposed between a first portion of the semiconductor layer and a vertical outer sidewall of the source region;
a second doped region disposed between a second portion of the semiconductor layer and a vertical outer sidewall of the drain region, wherein the first and second doped regions comprise dopants of a conductivity type that is different from dopants in the source and drain regions;
an interface layer comprising a metal oxide layer disposed within an opening of the second dielectric layer, wherein the interface layer is in contact with the source and drain regions; and
a metal crown structure disposed on top and side surfaces of the second dielectric layer and disposed directly on the interface layer, wherein the metal crown structure of a first transistor of the array of transistors comprises a first metal and the metal crown structure of a second transistor of the array of transistors comprises a second metal that is different from the first metal.
 
17. A biological field-effect transistor (BioFET) device, comprising:
a substrate comprising a semiconductor layer;
a multi-layer interconnect (MLI) structure disposed on a front side of the semiconductor layer and comprising an inter-metal dielectric layer and a conductive line;
an oxide layer disposed on a back side of the semiconductor layer, wherein the oxide layer extends into the semiconductor layer and into the inter-metal dielectric layer and is in contact with the conductive line;
a gate structure disposed on the front side of the semiconductor layer;
source and drain regions disposed in the semiconductor layer;
a first doped region disposed between a first portion of the semiconductor layer and the source region;
a second doped region disposed between a second portion of the semiconductor layer and the drain region, wherein the first and second doped regions comprise dopants of a conductivity type that is different from dopants in the source and drain regions;
a channel region disposed in the semiconductor layer, wherein the oxide layer comprises an opening aligned with the channel region,
wherein the source region comprises a first vertical inner sidewall in contact with the channel region and a first vertical outer sidewall in contact with the first doped region, and
wherein the drain region comprises a second vertical inner sidewall in contact with the channel region and a second vertical outer sidewall in contact with the second doped region; and
a conductive layer comprising a composite layer of a ruthenium oxide layer and a tungsten nitride layer disposed on the oxide layer.