Seohong Park

11 Questions 1 Answers 0 Followers

Questions related from Seohong Park

For GaN HEMTs, why does the depletion region extends a little bit into the drain side?

Is there an intuitive way to understand this?

23 September 2023 7,742 1 View

Why does the electric field peak near the drain side of the gate for GaN HEMTs?

I've seen simulations showing this, but is there an intuitive way to understand this?

23 September 2023 2,731 0 View

Does atmospheric Pressure CVD mean there are air molecules present in the chamber?

If the CVD process is performed at atmospheric pressure, does that mean there are as many air molecules (CO2, N2O, etc) present in the chamber as there are outside of the chamber? Or is the...

21 November 2022 4,962 1 View

Why does LPCVD result in more uniform deposition of thin films?

I understand that LPCVD process is surface-reaction limited due to the high diffusivity of the gas, but why does this help with depositing more uniform film?

20 November 2022 3,688 1 View

What is the maximum thickness of electroplated Ni I can achieve on a small piece?

I need to etch deep through the substrate, but the etch selectivity is not that high. How can I deposit a very thick layer of Ni using electroplating? I am thinking at least 20 um. Is there a...

09 March 2022 9,624 0 View

Difference between ICP, RIE, ICP-RIE etching?

I understand that inductively coupled plasma (ICP) means inductively coupled plasma, which has coils around the dielectric wall, and reactive ion etching (RIE) uses combination of chemical and...

04 February 2022 3,062 3 View

How to draw a band diagram of AlGaN/GaN high electron mobility transistor (HEMT)?

The charge profile of an AlGaN/GaN HEMT is usually modelled with six sheet charges as shown in the figure, polarization charge pair of AlGaN and GaN, and ionized surface donor states and 2DEG....

21 November 2021 5,570 2 View

HEMT figure of merit?

Hi, I would like to gain more insights on HEMT figures of merit (cutoff frequency f_T, maximum oscillation frequency f_max, breakdown voltage BV, on-resistance R_on, maximum drain current I_dmax)...

17 October 2021 8,130 1 View

What happens when the HOMO level of a hole transport layer is too deep (perovskite solar cell)?

I know that the maximum open circuit voltage of a perovskite solar cell increases with a deeper HOMO level of a hole transport layer, but what happens when it is too deep?

08 July 2020 9,964 2 View

How does perovskite solar cell work?

Do you dope the perovskite material the same way you dope silicon? Is there a P-type perovskite and N-type perovskite inside the cell?

26 March 2020 2,660 6 View

What is the role of a buffer layer in high electron mobility transistor (HEMT)?

For example, I see HEMT structures such as AlGaN Barrier / GaN Channel / GaN Buffer. What is the role of a buffer layer? Is it primarily used for heat conduction (heat sink)?

01 January 1970 8,134 1 View