Semiconductor device and method of manufacturing the same
A semiconductor device includes a substrate, a channel layer, a barrier layer, a ferroelectric composite material layer, a gate, a source and a drain. The channel layer and the barrier layer having a recess are disposed on the substrate in sequence. The ferroelectric composite material layer including a first dielectric layer, a charge trapping layer, a first ferroelectric material layer, a second dielectric layer and a second ferroelectric material layer is disposed in the recess. The gate is disposed on the ferroelectric composite material layer. The source and the drain are disposed on the barrier layer.
1. A semiconductor device comprising:
a substrate;
a channel layer disposed on the substrate;
a barrier layer disposed on the channel layer, the barrier layer having a recess, wherein the barrier layer has a portion underneath the recess, and the portion has a thickness;
a source and a drain disposed on the barrier layer;
a first dielectric layer covering a bottom surface of the recess;
a charge trapping layer disposed on the first dielectric layer;
a first ferroelectric material layer disposed on the charge trapping layer;
a second dielectric layer disposed on the first ferroelectric material layer;
a second ferroelectric material layer disposed on the second dielectric layer; and
a gate disposed over the second ferroelectric material layer.
2. The semiconductor device of claim 1 , further comprising a third dielectric layer disposed between the first ferroelectric material layer and the charge trapping layer.
3. The semiconductor device of claim 2 , wherein each of the first dielectric layer, the second dielectric layer and the third dielectric layer has a bandgap, and the bandgap respectively ranges between 7 eV to 12 eV.
4. The semiconductor device of claim 1 , wherein the thickness of the portion of the barrier layer ranges between 5 nm and 15 nm.
5. The semiconductor device of claim 1 , wherein the first and the second ferroelectric material layers respectively comprise a layer made of BaTiO 3 , KH 2 PO 4 , HfZrO 2 , SrBi 2 Ta 2 O 9 or PbZrTiO 3 .
6. The semiconductor device of claim 1 , wherein the recess has a depth, and the first dielectric layer has a thickness that is smaller than the depth.
7. The semiconductor device of claim 1 , wherein the recess has a first vertical sidewall and a second vertical sidewall opposite to the first vertical sidewall, and a first distance between the source and the first sidewall is smaller than a second distance between the drain and the second vertical sidewall.
8. The semiconductor device of claim 1 , further comprising a first passivation layer covering a portion of the barrier layer.
9. The semiconductor device of claim 8 , further comprising a second passivation layer disposed on the first passivation layer.