• ๋Œ€ํ•œ์ „๊ธฐํ•™ํšŒ
Mobile QR Code QR CODE : The Transactions of the Korean Institute of Electrical Engineers
  • COPE
  • kcse
  • ํ•œ๊ตญ๊ณผํ•™๊ธฐ์ˆ ๋‹จ์ฒด์ด์—ฐํ•ฉํšŒ
  • ํ•œ๊ตญํ•™์ˆ ์ง€์ธ์šฉ์ƒ‰์ธ
  • Scopus
  • crossref
  • orcid

  1. (Dept. of Electrical and Electronic Engineering, Pusan National University, Republic of Korea.)
  2. (Dept. of Semiconductor Systems Engineering, Kumoh National Institute of Technology, Republic of Korea.)



Silicon Carbide (SiC), MOSFET, H-shaped poly-Si gate (HPG), On-resistance, Gate-to-drain charge, Electric field

1. ์„œ ๋ก 

Silicon Carbide (SiC) ์ „๋ ฅ์šฉ MOSFET์€ ์šฐ์ˆ˜ํ•œ ์†Œ์žฌ ํŠน์„ฑ์„ ๊ธฐ๋ฐ˜์œผ๋กœ ๊ณ ์ „์•• ํ™˜๊ฒฝ์—์„œ ๊ณ ์† ์Šค์œ„์นญ ๋™์ž‘์ด ์š”๊ตฌ๋˜๋Š” ๋ถ„์•ผ์— ๋„๋ฆฌ ํ™œ์šฉ๋œ๋‹ค[1-5]. ์ด๋Ÿฌํ•œ ์‘์šฉ ๋ถ„์•ผ์—์„œ SiC ์ „๋ ฅ์šฉ MOSFET์˜ ์Šค์œ„์นญ ํŠน์„ฑ์„ ํ–ฅ์ƒํ•˜๊ธฐ ์œ„ํ•ด์„œ๋Š” ๊ฒŒ์ดํŠธ-๋“œ๋ ˆ์ธ ์ „ํ•˜๋ฅผ ๋‚ฎ์ถ”๋Š” ๊ฒƒ์ด ํ•„์ˆ˜์ ์ด๋‹ค[6-11]. ๊ทธ๋Ÿฌ๋‚˜ ๊ธฐ์กด์˜ SiC planar MOSFET์€ ํด๋ฆฌ์‹ค๋ฆฌ์ฝ˜ ๊ฒŒ์ดํŠธ๊ฐ€ ์„ ํ˜•์œผ๋กœ ๋ฐฐ์น˜๋œ ๊ตฌ์กฐ๋กœ ์ธํ•ด ๊ฒŒ์ดํŠธ-๋“œ๋ ˆ์ธ ์ „ํ•˜๊ฐ€ ๊ณผ๋„ํ•˜๊ฒŒ ์ถ•์ ๋˜๋Š” ๋ฌธ์ œ๋ฅผ ๊ฐ€์ง„๋‹ค. ์ด๋ฅผ ํ•ด๊ฒฐํ•˜๊ณ ์ž ๋‹ค์–‘ํ•œ ํด๋ฆฌ์‹ค๋ฆฌ์ฝ˜ ๊ฒŒ์ดํŠธ ๊ตฌ์กฐ๋ฅผ ์ ์šฉํ•œ SiC planar MOSFET์— ๋Œ€ํ•œ ์—ฐ๊ตฌ๊ฐ€ ์ˆ˜ํ–‰๋˜์—ˆ๋‹ค[12-17].

SiC Split-Gate MOSFET์€ ํด๋ฆฌ์‹ค๋ฆฌ์ฝ˜ ๊ฒŒ์ดํŠธ๋ฅผ ๋ถ„๋ฆฌํ•˜์—ฌ ๋‹จ์œ„ ๋ฉด์ ๋‹น ๊ฒŒ์ดํŠธ-๋“œ๋ ˆ์ธ ์ „ํ•˜ (Qgd,sp)๋ฅผ ํšจ๊ณผ์ ์œผ๋กœ ๊ฐ์†Œ์‹œํ‚จ ๋Œ€ํ‘œ์ ์ธ ๊ตฌ์กฐ์ด๋‹ค[12-14]. ๊ทธ๋Ÿฌ๋‚˜ ์ด ๊ตฌ์กฐ๋Š” ํด๋ฆฌ์‹ค๋ฆฌ์ฝ˜ ๊ฒŒ์ดํŠธ์˜ ๋ฉด์ ์ด ๊ฐ์†Œํ•˜์—ฌ ๊ธฐ์กด SiC planar MOSFET ๋Œ€๋น„ ๋‹จ์œ„ ๋ฉด์ ๋‹น ์˜จ์ €ํ•ญ (Ron,sp)์ด ์ฆ๊ฐ€ํ•˜๋Š” ๋ฌธ์ œ๊ฐ€ ์žˆ๋‹ค[13]. ๋˜ํ•œ, ๋ถ„๋ฆฌ๋œ ๊ฒŒ์ดํŠธ ๊ตฌ์กฐ์˜ ๋ชจ์„œ๋ฆฌ ๋ถ€๊ทผ์—์„œ ์ „๊ณ„ ์ง‘์ค‘ ํ˜„์ƒ์ด ๋ฐœ์ƒํ•  ์ˆ˜ ์žˆ์œผ๋ฉฐ, ์ด๋Š” ์žฅ๊ธฐ์ ์œผ๋กœ ์†Œ์ž์˜ ์‹ ๋ขฐ์„ฑ ๋ฐ ๋‚ด๊ตฌ์„ฑ์„ ์ €ํ•˜์‹œํ‚ฌ ๊ฐ€๋Šฅ์„ฑ์ด ์žˆ๋‹ค[18].

๋ณธ ๋…ผ๋ฌธ์—์„œ๋Š” ์ถ”๊ฐ€์ ์ธ ๊ณต์ • ์—†์ด Ron,sp์˜ ์ฆ๊ฐ€๋ฅผ ์ตœ์†Œํ™”ํ•˜๋ฉด์„œ Qgd,sp๋ฅผ ํšจ๊ณผ์ ์œผ๋กœ ๊ฐ์†Œ์‹œํ‚ฌ ์ˆ˜ ์žˆ๋Š” 1.2 kV SiC H-shaped poly-Si gate MOSFET (HPG MOSFET)์„ ์ œ์•ˆํ•œ๋‹ค. ์ œ์•ˆ๋œ ๊ตฌ์กฐ๋Š” ํด๋ฆฌ์‹ค๋ฆฌ์ฝ˜ ๊ฒŒ์ดํŠธ ์˜์—ญ ๋‚ด๋ถ€๋ฅผ ๋ถ€๋ถ„์ ์œผ๋กœ ์‹๊ฐํ•˜์—ฌ ํ˜•์„ฑํ•œ๋‹ค. 3์ฐจ์› TCAD ์‹œ๋ฎฌ๋ ˆ์ด์…˜์„ ํ†ตํ•ด ์‹๊ฐ ์˜์—ญ์˜ ๊ธธ์ด (LE)์™€ ํญ (WE)์— ๋”ฐ๋ฅธ ์ „๊ธฐ์  ํŠน์„ฑ์„ ๋ถ„์„ํ•œ ๊ฒฐ๊ณผ, ์ œ์•ˆ๋œ ๊ตฌ์กฐ๋Š” ๊ธฐ์กด SiC planar MOSFET ๋Œ€๋น„ Ron,sp์˜ ์ฆ๊ฐ€๊ฐ€ ๋ฏธ๋ฏธํ•œ ์ˆ˜์ค€์—์„œ ์œ ์ง€๋˜๋Š” ๋™์‹œ์— Qgd,sp๋ฅผ ํšจ๊ณผ์ ์œผ๋กœ ๊ฐ์†Œ์‹œํ‚ฌ ์ˆ˜ ์žˆ์Œ์„ ํ™•์ธํ•˜์˜€๋‹ค.

2. ์‹œ๋ฎฌ๋ ˆ์ด์…˜ ๋ฐฉ๋ฒ• ๋ฐ ์†Œ์ž ๊ตฌ์กฐ

TCAD ์‹œ๋ฎฌ๋ ˆ์ด์…˜์„ ํ†ตํ•ด 1.2 kV SiC planar MOSFET๊ณผ ์ œ์•ˆ๋œ SiC HPG MOSFET์˜ 3์ฐจ์› ๊ตฌ์กฐ๋ฅผ ์„ค๊ณ„ํ•˜์˜€๋‹ค. ๋‘ ๊ตฌ์กฐ์˜ N-drift ์ธต์€ ๋†๋„ 8 ร— 1015 cm-3, ๋‘๊ป˜๋Š” 10 ฮผm๋กœ ํ˜•์„ฑํ•˜์˜€๋‹ค. JFET ๋ฐ N-source ์˜์—ญ์€ ์งˆ์†Œ (N) ์ด์˜จ ์ฃผ์ž… ๊ณต์ •์œผ๋กœ ํ˜•์„ฑํ•˜์˜€์œผ๋ฉฐ, P-base ๋ฐ P-source ์˜์—ญ์€ ์•Œ๋ฃจ๋ฏธ๋Š„ (Al) ์ด์˜จ ์ฃผ์ž… ๊ณต์ •์œผ๋กœ ํ˜•์„ฑํ•˜์˜€๋‹ค. ์‹œ๋ฎฌ๋ ˆ์ด์…˜์—์„œ ๊ฐ ์˜์—ญ์€ ์ด์˜จ ์ฃผ์ž… ํ›„ ํ™œ์„ฑํ™”๋ฅผ ๋ฐ˜์˜ํ•˜์—ฌ ๊ตฌํ˜„ํ•˜์˜€๋‹ค. ์‹ค์ œ ์†Œ์ž์˜ ํŠน์„ฑ์„ ๋ณด๋‹ค ์ •ํ™•ํ•˜๊ฒŒ ๋ฐ˜์˜ํ•˜๊ธฐ ์œ„ํ•ด ์‹œ๋ฎฌ๋ ˆ์ด์…˜ ๋ชจ๋ธ์— ๋ถˆ์™„์ „ ์ด์˜จํ™” ํšจ๊ณผ์™€ ์ถฉ๋Œ ์ด์˜จํ™”๋ฅผ ๊ฐ๊ฐ ๊ณ ๋ คํ•œ ๋ถˆ์™„์ „ ์ด์˜จํ™” ๋ชจ๋ธ๊ณผ Okuto-Crowell ์ถฉ๋Œ ์ด์˜จํ™” ๋ชจ๋ธ์„ ์ ์šฉํ•˜์˜€๋‹ค.

๊ทธ๋ฆผ 1์€ ์„ค๊ณ„๋œ SiC planar MOSFET๊ณผ ์ œ์•ˆํ•œ HPG MOSFET์˜ 3์ฐจ์› ๊ตฌ์กฐ ๋ฐ ๋ ˆ์ด์•„์›ƒ์„ ๋‚˜ํƒ€๋‚ธ๋‹ค. HPG MOSFET์€ ํด๋ฆฌ์‹ค๋ฆฌ์ฝ˜ ๊ฒŒ์ดํŠธ ์˜์—ญ์„ ๋ถ€๋ถ„์ ์œผ๋กœ ์‹๊ฐํ•˜์—ฌ ํ˜•์„ฑ๋œ Hํ˜• ๊ตฌ์กฐ๋ฅผ ๊ฐ€์ง€๋ฉฐ, LE์™€ WE์„ ๋ณ€์ˆ˜๋กœ ์„ค์ •ํ•˜์—ฌ ์ตœ์ ์˜ ๊ตฌ์กฐ๋ฅผ ๊ฒฐ์ •ํ•˜์˜€๋‹ค. ์ œ์•ˆํ•œ Hํ˜• ํด๋ฆฌ์‹ค๋ฆฌ์ฝ˜ ๊ฒŒ์ดํŠธ ๊ตฌ์กฐ๋Š” ๊ทธ๋ฆผ 1์˜ ๋ ˆ์ด์•„์›ƒ ๋‹จ์œ„ ์…€ ๋‚ด๋ถ€์—์„œ ๋ช…ํ™•ํžˆ ํ™•์ธํ•  ์ˆ˜ ์žˆ๋‹ค.

๊ทธ๋ฆผ 1. 1.2 kV SiC MOSFET์˜ 3-D ๊ตฌ์กฐ์™€ ๋ ˆ์ด์•„์›ƒ

Fig. 1. The 3-D structure and layout of the 1.2 kV SiC MOSFET

../../Resources/kiee/KIEE.2025.74.5.905/fig1.png

๊ทธ๋ฆผ 2๋Š” 1.2 kV SiC planar MOSFET๊ณผ ์ œ์•ˆํ•œ HPG MOSFET์˜ ํด๋ฆฌ์‹ค๋ฆฌ์ฝ˜ ๊ฒŒ์ดํŠธ ์ „๊ทน ํ˜•์„ฑ์„ ์œ„ํ•œ ๊ณต์ • ๊ณผ์ •์„ ๋‚˜ํƒ€๋‚ธ๋‹ค. ๊ณต์ •์€ ํด๋ฆฌ์‹ค๋ฆฌ์ฝ˜ ๊ฒŒ์ดํŠธ ํ˜•์„ฑ, ์†Œ์Šค ์ „๊ทน ํ˜•์„ฑ์„ ์œ„ํ•œ ๊ฒŒ์ดํŠธ ์ „๊ทน ์˜์—ญ์˜ ์‹๊ฐ, ์†Œ์Šค์™€ ๊ฒŒ์ดํŠธ ์ „๊ทน์˜ ์ ˆ์—ฐ์„ ์œ„ํ•œ ์ธต๊ฐ„ ์ ˆ์—ฐ๋ง‰ (ILD)์˜ ํŒจํ„ฐ๋‹ ์ˆœ์„œ๋กœ ์ง„ํ–‰ํ•˜์˜€๋‹ค. ๊ทธ๋ฆผ 2 (b)์—์„œ ๋‚˜ํƒ€๋‚ธ ๋ฐ”์™€ ๊ฐ™์ด ์ œ์•ˆ๋œ HPG MOSFET์˜ Hํ˜• ๊ฒŒ์ดํŠธ๋Š” ํด๋ฆฌ์‹ค๋ฆฌ์ฝ˜ ๊ฒŒ์ดํŠธ๋ฅผ ๋ถ€๋ถ„์ ์œผ๋กœ ์‹๊ฐํ•˜์—ฌ ๊ตฌํ˜„ํ•˜์˜€๋‹ค. ์ด๋Ÿฌํ•œ ๊ตฌ์กฐ๋Š” ๊ธฐ์กด planar MOSFET ๋Œ€๋น„ ๊ฒŒ์ดํŠธ ์ „๊ทน ํ˜•์ƒ์ด ๋ณต์žกํ•ด์ง€๋ฏ€๋กœ, ํด๋ฆฌ์‹ค๋ฆฌ์ฝ˜ ๊ฒŒ์ดํŠธ์˜ ๋ชจ์„œ๋ฆฌ ๋ถ€๊ทผ ์‚ฐํ™”๋ง‰์—์„œ ์ „๊ณ„ ์ง‘์ค‘ ํ˜„์ƒ์ด ๋ฐœ์ƒํ•  ๊ฐ€๋Šฅ์„ฑ์ด ์žˆ๋‹ค[13]. ๋”ฐ๋ผ์„œ ๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” ์ตœ์  ์„ค๊ณ„ ์กฐ๊ฑด์„ ๊ฒฐ์ •ํ•  ๋•Œ ํด๋ฆฌ์‹ค๋ฆฌ์ฝ˜ ๊ฒŒ์ดํŠธ ๋ชจ์„œ๋ฆฌ ๋ถ€๊ทผ์—์„œ์˜ ์‚ฐํ™”๋ง‰ ์ตœ๋Œ€ ์ „๊ณ„ (Eox,max)๋ฅผ ํ•จ๊ป˜ ๋ถ„์„ํ•˜์˜€๋‹ค. ๋‘ ๊ตฌ์กฐ์˜ ๊ณต์ • ๋ฐ ์„ค๊ณ„ ๋ณ€์ˆ˜๋Š” ํ‘œ 1์— ๋‚˜ํƒ€๋‚ด์—ˆ๋‹ค.

๊ทธ๋ฆผ 2. 1.2 kV SiC MOSFET์˜ ํด๋ฆฌ์‹ค๋ฆฌ์ฝ˜ ๊ฒŒ์ดํŠธ ์ „๊ทน์„ ํ˜•์„ฑํ•˜๊ธฐ ์œ„ํ•œ ๊ณต์ • ๊ณผ์ •

Fig. 2. Process steps for the formation of the poly-Si gate electrode in the 1.2 kV SiC MOSFET

../../Resources/kiee/KIEE.2025.74.5.905/fig2.png

ํ‘œ 1 1.2 kV SiC planar MOSFET๊ณผ HPG MOSFET์˜ ๊ณต์ • ๋ฐ ์„ค๊ณ„ ๋ณ€์ˆ˜

Table 1 Process and design parameters of the 1.2 kV SiC planar MOSFET and HPG MOSFET

SiC planar MOSFET

SiC

HPG MOSFET

Unit Cell Area [ยตm2]

36

JFET Width [ยตm]

3.2

LE [ยตm]

0.0

0.6, 0.8, 1.0, 1.2, 1.4, 1.6

WE [ยตm]

0.0

1.8, 3.0, 4.2

JFET Concentration [cm-3]

3 ร— 1016

P-base Concentration [cm-3]

1 ร— 1019

3. ๊ฒฐ๊ณผ ๋ฐ ๋ถ„์„

๊ทธ๋ฆผ 3์€ VGS = -5 V ๋ฐ VDS = 1.2 kV ์กฐ๊ฑด์—์„œ ์ถ”์ถœํ•œ ์ œ์•ˆ๋œ ๊ตฌ์กฐ์˜ LE์— ๋”ฐ๋ฅธ Eox,max๋ฅผ ๋‚˜ํƒ€๋‚ธ๋‹ค. ๋ถ„์„ ๊ฒฐ๊ณผ, LE๊ฐ€ 0.6 ฮผm์ผ ๋•Œ Eox,max๊ฐ€ ์ตœ๋Œ“๊ฐ’์„ ๊ฐ€์ง€๋ฉฐ, LE๊ฐ€ ์ด ๊ฐ’์„ ์ดˆ๊ณผํ•˜๋ฉด Eox,max๋Š” ์ ์ฐจ ๊ฐ์†Œํ•˜๋Š” ๊ฒฝํ–ฅ์„ ๋ณด์˜€๋‹ค. ์ด๋Š” LE๊ฐ€ ๊ธธ์–ด์ง์— ๋”ฐ๋ผ ๊ฒŒ์ดํŠธ ๋ชจ์„œ๋ฆฌ ๋ถ€๊ทผ์˜ ์ „๊ณ„ ์ง‘์ค‘ ํ˜„์ƒ์ด ํšจ๊ณผ์ ์œผ๋กœ ์™„ํ™”๋˜๊ธฐ ๋•Œ๋ฌธ์ด๋‹ค. ํŠนํžˆ LE๊ฐ€ 1.2 ฮผm ์ด์ƒ์ธ ๊ฒฝ์šฐ Eox,max๋Š” 3 MV/cm ๋ฏธ๋งŒ์œผ๋กœ ์œ ์ง€๋˜์–ด ์†Œ์ž์˜ ์žฅ๊ธฐ์  ์•ˆ์ •์„ฑ์„ ํ™•๋ณดํ•  ์ˆ˜ ์žˆ์Œ์„ ํ™•์ธํ•˜์˜€๋‹ค.

๊ทธ๋ฆผ 3. 1.2 kV SiC HPG MOSFET์˜ LE์— ๋”ฐ๋ฅธ Eox,max ๋ณ€ํ™” (VGS = -5 V, VDS = 1.2 kV)

Fig. 3. Variation of the Eox,max with respect to LE in the 1.2 kV SiC HPG MOSFET (VGS = -5 V, VDS = 1.2 kV)

../../Resources/kiee/KIEE.2025.74.5.905/fig3.png

๊ทธ๋ฆผ 4๋Š” VGS = 18 V ๋ฐ VDS = 10 V ์กฐ๊ฑด์—์„œ ์ถ”์ถœํ•œ ์ œ์•ˆ๋œ ๊ตฌ์กฐ์˜ LE์— ๋”ฐ๋ฅธ Ron,sp์™€ Ron,sp์˜ ์ฆ๊ฐ€์œจ (ฮ”Ron,sp)์„ ๋‚˜ํƒ€๋‚ธ๋‹ค. ๋ถ„์„ ๊ฒฐ๊ณผ, LE๊ฐ€ ์ฆ๊ฐ€ํ• ์ˆ˜๋ก Ron,sp๊ฐ€ ์ ์ง„์ ์œผ๋กœ ์ฆ๊ฐ€ํ•˜๋Š” ๊ฒฝํ–ฅ์„ ๋ณด์˜€๋‹ค. ์ด๋Š” LE๊ฐ€ ์ฆ๊ฐ€ํ•จ์— ๋”ฐ๋ผ ํด๋ฆฌ์‹ค๋ฆฌ์ฝ˜ ๊ฒŒ์ดํŠธ์˜ ๋ฉด์ ์ด ๊ฐ์†Œํ•˜๊ณ , ๊ทธ๋กœ ์ธํ•ด ๊ฒŒ์ดํŠธ ํ•˜๋‹จ๋ถ€์— ํ˜•์„ฑ๋˜๋Š” ์ถ•์ ์ธต์˜ ๋ฉด์  ๋˜ํ•œ ์ถ•์†Œ๋˜์–ด ์ „๋ฅ˜ ํ๋ฆ„ ๊ฒฝ๋กœ๊ฐ€ ์ œํ•œ๋˜๊ธฐ ๋•Œ๋ฌธ์ด๋‹ค. ํŠนํžˆ ๊ทธ๋ฆผ 4 (b)์—์„œ ๋ณผ ์ˆ˜ ์žˆ๋“ฏ์ด, Ron,sp๋Š” LE๊ฐ€ 1.4 ฮผm ์ด์ƒ์ผ ๋•Œ ๊ธ‰๊ฒฉํžˆ ์ฆ๊ฐ€ํ•˜์˜€๋‹ค.

๊ทธ๋ฆผ 4. 1.2 kV SiC HPG MOSFET์˜ LE์— ๋”ฐ๋ฅธ (a) Ron,sp์™€ (b) โˆ†Ron,sp ๋ณ€ํ™” (VGS = 18 V, VDS = 10 V)

Fig. 4. Variation of (a) Ron,sp and (b) ฮ”Ron,sp with respect to LE in the 1.2 kV SiC HPG MOSFET (VGS = 18 V, VDS = 10 V)

../../Resources/kiee/KIEE.2025.74.5.905/fig4-1.png

../../Resources/kiee/KIEE.2025.74.5.905/fig4-2.png

๊ทธ๋ฆผ 5๋Š” VGS = 0 V ๋ฐ VDS = 1.2 kV ์กฐ๊ฑด์—์„œ ์ œ์•ˆ๋œ ๊ตฌ์กฐ์˜ LE๊ฐ€ ๊ฐ๊ฐ 1.2 ฮผm ๋ฐ 1.4 ฮผm ์ผ ๋•Œ์˜ ์ „๋ฅ˜ ๋ถ„ํฌ๋ฅผ ๋‚˜ํƒ€๋‚ธ๋‹ค. ๋ถ„์„ ๊ฒฐ๊ณผ, ์ œ์•ˆ๋œ ๊ตฌ์กฐ์˜ ์ „๋ฅ˜ ๋ฐ€๋„๋Š” LE์— ๊ด€๊ณ„์—†์ด ๋ชจ๋‘ 1 ฮผAยทcm-2 ์ˆ˜์ค€์œผ๋กœ ์œ ์‚ฌํ•˜๊ฒŒ ๋„์ถœ๋˜์—ˆ์œผ๋ฉฐ, LE์˜ ๋ณ€ํ™”์— ๋”ฐ๋ฅธ ์˜ํ–ฅ์€ ํฌ์ง€ ์•Š์€ ๊ฒƒ์œผ๋กœ ํ™•์ธ๋˜์—ˆ๋‹ค.

์ด์— ๋”ฐ๋ผ, ์ œ์•ˆ๋œ ๊ตฌ์กฐ์˜ LE์˜ ๋ณ€ํ™”๊ฐ€ ์ „๊ธฐ์  ํŠน์„ฑ์— ๋ฏธ์น˜๋Š” ์˜ํ–ฅ์„ ๋ณด๋‹ค ์ •๋ฐ€ํ•˜๊ฒŒ ๋ถ„์„ํ•˜๊ณ ์ž ํ•ญ๋ณต์ „์•• (BV)๊ณผ ๋ฌธํ„ฑ์ „์•• (Vth) ํŠน์„ฑ์„ ์ถ”๊ฐ€๋กœ ํ‰๊ฐ€ํ•˜์˜€์œผ๋ฉฐ, ๊ทธ ๊ฒฐ๊ณผ๋ฅผ ํ‘œ 2์— ๋‚˜ํƒ€๋‚ด์—ˆ๋‹ค.

๊ทธ๋ฆผ 5. 1.2 kV SiC HPG MOSFET์˜ ์ „๋ฅ˜ ๋ถ„ํฌ : (a) LE = 1.2 ฮผm, (b) LE = 1.4 ฮผm (VGS = 0 V, VDS = 1.2 kV)

Fig. 5. Current distribution of the 1.2 kV SiC HPG MOSFET with (a) LE = 1.2 ฮผm or (b) LE =1.4 ฮผm (VGS = 0 V, VDS = 1.2 kV)

../../Resources/kiee/KIEE.2025.74.5.905/fig5.png

ํ‘œ 2 1.2 kV SiC HPG MOSFET์˜ LE์— ๋”ฐ๋ฅธ ํ•ญ๋ณต์ „์•• ๋ฐ ๋ฌธํ„ฑ์ „์•• ๋น„๊ต

Table 2 Comparison of breakdown voltage and threshold voltage of the 1.2 kV SiC HPG MOSFET for different LE values

SiC HPG MOSFET

LE = 1.2 [ยตm]

LE = 1.4

[ยตm]

BV* [V]

1620

1624

Vth** [V]

5.61

5.61

* VGS = 0 V, ID = 10 ฮผA

** VDS = 5 V, ID = 1 mA

์ œ์•ˆ๋œ ๊ตฌ์กฐ์—์„œ LE๊ฐ€ 1.2 ฮผm์ธ ๊ฒฝ์šฐ์™€ 1.4 ฮผm ๊ฒฝ์šฐ์˜ BV ๋ฐ Vth ์ฐจ์ด๋Š” ๊ฑฐ์˜ ์—†์—ˆ์œผ๋‚˜, LE๊ฐ€ 1.4 ฮผm ์ด์ƒ์ผ ๊ฒฝ์šฐ Ron,sp๊ฐ€ ๊ธ‰๊ฒฉํžˆ ์ฆ๊ฐ€ํ•˜๋Š” ๊ฒฝํ–ฅ์„ ๋ณด์˜€์œผ๋ฏ€๋กœ, ๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” LE์˜์ตœ์ ๊ฐ’์„ 1.2 ฮผm ์„ค์ •ํ•˜์˜€๋‹ค.

์‹๊ฐ ์˜์—ญ์— ๋”ฐ๋ฅธ ์ œ์•ˆ๋œ ๊ตฌ์กฐ์˜ ์„ฑ๋Šฅ์„ ๊ฒ€์ฆํ•˜๊ณ  ์ตœ์  ์กฐ๊ฑด์„ ๋„์ถœํ•˜๊ธฐ ์œ„ํ•ด, LE์˜ ์ตœ์ ๊ฐ’ (1.2 ฮผm)์„ ๋ฐ˜์˜ํ•œ ์ƒํƒœ์—์„œ WE ๋ณ€ํ™”์— ๋”ฐ๋ฅธ ์ „๊ธฐ์  ํŠน์„ฑ์„ ๋ถ„์„ํ•˜์˜€๋‹ค. ์ œ์•ˆ๋œ ๊ตฌ์กฐ์˜ ๊ฒŒ์ดํŠธ ์ „ํ•˜ ํŠน์„ฑ์€ TCAD mixed-mode ์‹œ๋ฎฌ๋ ˆ์ด์…˜์„ ํ†ตํ•ด ํ‰๊ฐ€ํ•˜์˜€๋‹ค. ์‹œ๋ฎฌ๋ ˆ์ด์…˜์€ ๊ทธ๋ฆผ 6์— ๋‚˜ํƒ€๋‚ธ ํšŒ๋กœ๋„๋ฅผ ๊ธฐ๋ฐ˜์œผ๋กœ VDD = 800 V ๋ฐ ID = 10 A ์กฐ๊ฑด์—์„œ ๊ฒŒ์ดํŠธ ๋‹จ์ž์— 1 mA์˜ ์ •์ „๋ฅ˜์›์„ ์ธ๊ฐ€ํ•˜์—ฌ ์ˆ˜ํ–‰ํ•˜์˜€๋‹ค. Qgd,sp๋Š” ๊ฒŒ์ดํŠธ ์ „์••-๊ฒŒ์ดํŠธ ์ „ํ•˜ ๊ณก์„ ์˜ plateau ๊ตฌ๊ฐ„์—์„œ ์ถ”์ถœํ•˜์˜€๋‹ค[19].

๊ทธ๋ฆผ 6. ๊ฒŒ์ดํŠธ ์ „ํ•˜ ํŠน์„ฑ์„ ํ‰๊ฐ€ํ•˜๊ธฐ ์œ„ํ•ด TCAD mixed-mode ์‹œ๋ฎฌ๋ ˆ์ด์…˜์œผ๋กœ ๊ตฌํ˜„ํ•œ ํšŒ๋กœ๋„

Fig. 6. Schematic diagram utilized in the TCAD mixed-mode simulation for the evaluation of gate charge characteristics

../../Resources/kiee/KIEE.2025.74.5.905/fig6.png

๊ทธ๋ฆผ 7์€ WE์— ๋”ฐ๋ฅธ Ron,sp์™€ Qgd,sp์˜ ๋ณ€ํ™”๋ฅผ ๋‚˜ํƒ€๋‚ธ๋‹ค. WE๊ฐ€ ์ฆ๊ฐ€ํ•จ์— ๋”ฐ๋ผ Qgd,sp๋Š” ํฌ๊ฒŒ ๊ฐ์†Œํ•˜๋Š” ๊ฒฝํ–ฅ์„ ๋‚˜ํƒ€๋ƒˆ๋‹ค. ์ด๋Š” WE์˜ ์ฆ๊ฐ€๋กœ ์ธํ•ด ํด๋ฆฌ์‹ค๋ฆฌ์ฝ˜ ๊ฒŒ์ดํŠธ ๋ฉด์ ์ด ๊ฐ์†Œํ•˜์—ฌ ๊ฒŒ์ดํŠธ ํ•˜๋ถ€ ์ถ•์  ์ „ํ•˜๋Ÿ‰์ด ๋น„๋ก€ํ•˜์—ฌ ๊ฐ์†Œํ–ˆ๊ธฐ ๋•Œ๋ฌธ์ด๋‹ค. ๋ฐ˜๋ฉด, Ron,sp๋Š” WE์˜ ๋ณ€ํ™”์— ๋”ฐ๋ฅธ ์˜ํ–ฅ์ด ๋ฏธ๋ฏธํ•˜์˜€๋‹ค. ์ด๋ฅผ ํ†ตํ•ด WE์˜ ์ฆ๊ฐ€์— ๋”ฐ๋ฅธ ๊ตฌ์กฐ์  ๋ณ€ํ™”๊ฐ€ ์†Œ์ž์˜ ์˜จ์ €ํ•ญ์— ๋ฏธ์น˜๋Š” ์˜ํ–ฅ์€ ์ œํ•œ์ ์ž„์„ ์•Œ ์ˆ˜ ์žˆ์—ˆ๋‹ค.

๊ทธ๋ฆผ 7. 1.2 kV HPG MOSFET์˜ WE์— ๋”ฐ๋ฅธ Ron,sp์™€ Qgd,sp ํŠน์„ฑ

Fig. 7. Characteristics of Ron,sp and Qgd,sp with respect to WE in the 1.2 kV HPG MOSFET

../../Resources/kiee/KIEE.2025.74.5.905/fig7.png

๊ทธ๋ฆผ 8์€ VGS = -5 V ๋ฐ VDS = 1.2 kV ์กฐ๊ฑด์—์„œ ์ถ”์ถœํ•œ ์ œ์•ˆ๋œ ๊ตฌ์กฐ์˜ WE์— ๋”ฐ๋ฅธ Eox,max๋ฅผ ๋‚˜ํƒ€๋‚ธ๋‹ค. ๋ถ„์„ ๊ฒฐ๊ณผ, WE๊ฐ€ ์ฆ๊ฐ€ํ•จ์— ๋”ฐ๋ผ Eox,max๋„ ์ ์ง„์ ์œผ๋กœ ์ฆ๊ฐ€ํ•˜๋Š” ๊ฒฝํ–ฅ์„ ๋ณด์˜€๋‹ค. ์ด๋Š” WE์˜ ์ฆ๊ฐ€๋กœ ์ธํ•ด ํด๋ฆฌ์‹ค๋ฆฌ์ฝ˜ ๊ฒŒ์ดํŠธ์˜ ๋ชจ์„œ๋ฆฌ์™€ ์ธ์ ‘ํ•œ P-source ๋ชจ์„œ๋ฆฌ ๊ฐ„์˜ ๊ฑฐ๋ฆฌ๊ฐ€ ๋ฉ€์–ด์ง€๋ฉด์„œ, ๊ฒŒ์ดํŠธ ๋ชจ์„œ๋ฆฌ์— ์ „๊ณ„๊ฐ€ ๋”์šฑ ์ง‘์ค‘๋˜๊ธฐ ๋•Œ๋ฌธ์œผ๋กœ ํŒ๋‹จ๋œ๋‹ค. ํŠนํžˆ WE๊ฐ€ 4.2 ฮผm์ผ ๋•Œ๋Š” Eox,max๊ฐ€ 3 MV/cm๋ฅผ ์ดˆ๊ณผํ•˜์—ฌ ์žฅ๊ธฐ ์‹ ๋ขฐ์„ฑ์— ๋ฌธ์ œ๊ฐ€ ๋ฐœ์ƒํ•  ์ˆ˜ ์žˆ์œผ๋ฏ€๋กœ, ๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” WE์˜ ์ตœ์ ๊ฐ’์„ 3.0 ฮผm๋กœ ์„ค์ •ํ•˜์˜€๋‹ค.

1.2 kV SiC planar MOSFET (LE = 0.0 ฮผm)๊ณผ HPG MOSFET (LE = 1.2 ฮผm)์˜ ์ „๊ธฐ์  ํŠน์„ฑ์„ ๋น„๊ตํ•œ ๊ฒฐ๊ณผ๋ฅผ ํ‘œ 3์— ๋‚˜ํƒ€๋‚ด์—ˆ๋‹ค. ์ œ์•ˆ๋œ ๊ตฌ์กฐ์˜ Ron,sp์™€ Qgd,sp ๊ฒฐ๊ณผ์—๋Š” SiC planar MOSFET์˜ ๊ฐ’ ๋Œ€๋น„ ์ฆ๊ฐ์œจ์„ ํ•จ๊ป˜ ๋‚˜ํƒ€๋‚ด์—ˆ๋‹ค.

๊ทธ๋ฆผ 8. 1.2 kV HPG MOSFET์˜ WE์— ๋”ฐ๋ฅธ Eox,max ๋ถ„ํฌ (VGS = -5 V, VDS = 1.2 kV)

Fig. 8. Variation of the Eox,max with respect to the WE in the 1.2 kV HPG MOSFET (VGS = -5 V, VDS = 1.2 kV)

../../Resources/kiee/KIEE.2025.74.5.905/fig8.png

ํ‘œ 3 1.2 kV SiC planar MOSFET๊ณผ HPG MOSFET์˜ ์ „๊ธฐ์  ํŠน์„ฑ ๋น„๊ต

Table 3 Comparisons of electrical characteristics of the 1.2 kV SiC planar MOSFET and HPG MOSFET

WE

[ยตm

Ron,sp

[mฮฉยทcm2]

Qgd,sp

[nC/cm2]

BV [V]

Vth [V]

SiC

planar

MOSFET

0.0

6.12

54.8

1620

5.61

SiC

HPG MOSFET

1.8

6.15

(+0.49 %)

51.0

(-6.9 %)

1614

5.61

3.0

6.17 (+0.81 %)

46.5 (-15.1 %)

1613

5.61

4.2

6.23

(+1.80 %)

42.4 (-22.6 %)

1613

5.62

4. ๊ฒฐ ๋ก 

๋ณธ ๋…ผ๋ฌธ์—์„œ๋Š” Ron,sp์˜ ํฐ ์ฆ๊ฐ€ ์—†์ด Qgd,sp๋ฅผ ํšจ๊ณผ์ ์œผ๋กœ ๊ฐ์†Œ์‹œํ‚ค๊ธฐ ์œ„ํ•ด Hํ˜• ๊ฒŒ์ดํŠธ๋ฅผ ์ ์šฉํ•œ 1.2 kV SiC MOSFET์„ ์ œ์•ˆํ•˜์˜€๋‹ค. ์„ค๊ณ„ ๋ณ€์ˆ˜๋กœ์„œ LE์™€ WE์„ ์„ค์ •ํ•˜๊ณ , ์ด์— ๋”ฐ๋ฅธ Ron,sp, Qgd,sp, Eox,max์˜ ๋ณ€ํ™”๋ฅผ ๋ถ„์„ํ•˜์˜€๋‹ค. ๊ทธ ๊ฒฐ๊ณผ, LE = 1.2 ฮผm, WE = 3.0 ฮผm์ผ ๋•Œ ์ œ์•ˆ๋œ ๊ตฌ์กฐ๊ฐ€ ์ตœ์ ์˜ ์„ฑ๋Šฅ์„ ๋ณด์˜€๋‹ค. ์ด ์กฐ๊ฑด์—์„œ ์ œ์•ˆ๋œ ๊ตฌ์กฐ์˜ Qgd,sp๋Š” ๊ธฐ์กด SiC planar MOSFET ๋Œ€๋น„ 15.1 % ๊ฐ์†Œํ•˜์˜€๊ณ , Ron,sp๋Š” 0.81 % ์ฆ๊ฐ€์— ๊ทธ์ณค์œผ๋ฉฐ, Eox,max๋Š” 3 MV/cm ์ดํ•˜๋กœ ์œ ์ง€๋˜์—ˆ๋‹ค. ์ด๋Ÿฌํ•œ ๊ฒฐ๊ณผ๋Š” ์ œ์•ˆ๋œ ๊ตฌ์กฐ๊ฐ€ ๊ธฐ์กด SiC planar MOSFET ๋Œ€๋น„ ์†Œ์ž์˜ ๋™์ž‘ ํšจ์œจ์„ ํšจ๊ณผ์ ์œผ๋กœ ํ–ฅ์ƒ์‹œํ‚ฌ ์ˆ˜ ์žˆ์Œ์„ ์‹œ์‚ฌํ•œ๋‹ค.

Acknowledgements

๋ณธ ์—ฐ๊ตฌ๋Š” 2025๋…„๋„ ์ •๋ถ€(์‚ฐ์—…ํ†ต์ƒ์ž์›๋ถ€)์˜ ์žฌ์›์œผ๋กœ ํ•œ๊ตญ์‚ฐ์—…๊ธฐ์ˆ ์ง„ํฅ์›์˜ ์ง€์›์„ ๋ฐ›์•„ ์ˆ˜ํ–‰๋œ ์—ฐ๊ตฌ์ž„ (RS-2025-02214408, 2025๋…„ ์‚ฐ์—…ํ˜์‹ ์ธ์žฌ์„ฑ์žฅ์ง€์›์‚ฌ์—…)

References

1 
T. Yin, C. Xu, L. Lin and K. Jing, โ€œA SiC MOSFET and Si IGBT Hybrid Modular Multilevel Converter with Specialized Modulation Scheme,โ€ IEEE Trans. Power Electron., vol. 35, no. 12, pp. 12623~12628, 2020. DOI:10.1109/TPEL.2020.2993366DOI
2 
P. Alexakis, O. Alatise, J. Hu, S. Jahdi, L. Ran and P. A. Mawby, โ€œImproved Electrothermal Ruggedness in SiC MOSFETs Compared with Si IGBTs,โ€ IEEE Trans. Electron Devices, vol. 61, no. 7, pp. 2278~2286, 2014. DOI:10.1109/TED.2014.2323152DOI
3 
S. Yin, Y. Gu, S. Deng, X. Xin and G. Dai, โ€œComparative Investigation of Surge Current Capabilities of Si IGBT and SiC MOSFET for Pulsed Power Application,โ€ IEEE Trans. Plasma Sci., vol. 46, no. 8, pp. 2979~2984, 2018. DOI:1.1109/TPS.2018.2849778DOI
4 
S. Hazra, A. De, L. Cheng, J. Palmour, M. Schupbach, B. A. Hull, S. Allen and S. Bhattacharya, โ€œHigh Switching Performance of 1700-V, 50-A SiC Power MOSFET Over Si IGBT/BiMOSFET for Advanced Power Conversion Applications,โ€ IEEE Trans. Power Electron., vol. 31, no. 7, pp. 4742~4754, 2016. DOI:10.1109/TPEL.2015.2432012DOI
5 
A. Hussein, A. Castellazzi, P. Wheeler and C. Klumpner, โ€œPerformance benchmark of Si IGBTs vs. SiC MOSFETs in small-scale wind energy conversion systems,โ€ Proc. IEEE Int. Power Electron. Motion Control Conf., Varna, Bulgaria, pp. 963~968, 2016. DOI:10.1109/EPEPEMC.2016.7752124DOI
6 
X. Li, J. Jiang, A. Q. Huang, S. Guo, X. Deng, B. Zhang and X. She, โ€œA SiC Power MOSFET Loss Model Suitable for High-Frequency Applications,โ€ IEEE Trans. Ind. Electron., vol. 64, no. 10, pp. 8268~8276, 2017. DOI:10.1109/TIE.2017DOI
7 
A. Q. Huang, โ€œNew unipolar switching power device figures of merit,โ€ IEEE Electron Device Lett., vol. 25, no. 5, pp. 298~301, 2004. DOI:10.1109/LED.2004.826533DOI
8 
A. Merkert, T. Krone and A. Mertens, โ€œCharacterization and Scalable Modeling of Power Semiconductors for Optimized Design of Traction Inverters with Si and SiC Devices,โ€ IEEE Trans. Power Electron., vol. 29, no. 5, pp. 2238~2245, 2014. DOI:10.1109/TPEL.2013.2294682DOI
9 
Y. Chen, F. C. Lee, L. Amoroso and H. P. Wu, โ€œA resonant gate driver with efficient energy recovery,โ€ IEEE Trans. Power Electron., vol. 19, no. 2, pp. 525~531, 2004. DOI:10.1109/TPEL.2003.823206DOI
10 
A. Jafari, M. Nikoo, N. Perera, H. K. Yildirim, F. Karakaya, R. Soleimanzadeh and E. Matioli, โ€œComparison of Wide Band Gap Technologies for Soft-Switching Losses at High Frequencies,โ€ IEEE Trans. Power Electron., vol. 35, no. 12, pp. 12595~12600, 2020. DOI:10.1109/TPEL.2020.2990628DOI
11 
B. J. Baliga, โ€œPower semiconductor device figure of merit for high-frequency applications,โ€ IEEE Electron Device Lett., vol. 10, no. 10, pp. 455~457, 1989. DOI:10.1109/55.43098DOI
12 
A. Agarwal, K. Han and B. J. Baliga, โ€œ2.3 kV 4H-SiC Accumulation-Channel Split-Gate planar Power MOSFETs with Reduced Gate Charge,โ€ IEEE J. Electron Devices Soc., vol. 8, pp. 499~504, 2020. DOI:10.1109/JEDS.2020.2991355DOI
13 
K. Han, B. J. Baliga and W. Sung, โ€œSplit-Gate 1.2-kV 4H-SiC MOSFET: Analysis and Experimental Validation,โ€ IEEE Electron Device Lett., vol. 38, no. 10, pp. 1437~1440, 2017. DOI:10.1109/LED.2017.2738616DOI
14 
T. Sakai and N. Murakami, โ€œA new VDMOSFET structure with reduced reverse transfer capacitance,โ€ IEEE Trans. Electron Devices, vol. 36, no. 7, pp. 1381~1386, 1989. DOI:10.1109/16.30945DOI
15 
K. Han, B. J. Baliga and W. Sung, โ€œA Novel 1.2 kV 4H-SiC Buffered-Gate (BG) MOSFET: Analysis and Experimental Results,โ€ IEEE Electron Device Lett., vol. 39, no. 2, pp. 248~251, 2018. DOI:10.1109/LED.2017.2785771DOI
16 
D. Ueda, H. Takagi and G. Kano, โ€œA new vertical double diffused MOSFETโ€”The self-aligned terraced-gate MOSFET,โ€ IEEE Trans. Electron Devices, vol. 31, no. 4, pp. 416~420, 1984. DOI:10.1109/T-ED.1984.21543DOI
17 
P. Vudumula and S. Kotamraju, โ€œDesign and Optimization of 1.2-kV SiC planar Inversion MOSFET Using Split Dummy Gate Concept for High-Frequency Applications,โ€ IEEE Trans. Electron Devices, vol. 66, no. 12, pp. 5266~5271, 2019. DOI:10.1109/TED.2019.2949459DOI
18 
W. Chen, B. Zhang and Z. Li, โ€œOptimization of the VDMOSFET structure with reduced gate charge,โ€ Semicond. Sci. Technol., vol. 22, no. 9, pp. 1033~1038, 2007. DOI:10.1088/0268-1242/22/9/010DOI
19 
W. Ni, X. Wang, M. Xu, M. Li, C. Feng and H. Xiao, โ€œComparative Study of SiC planar MOSFETs With Different p-Body Designs,โ€ IEEE Trans. Electron Devices, vol. 67, no. 3, pp. 1071~1076, 2020. DOI: 10.1109/TED.2020.2966775DOI

์ €์ž์†Œ๊ฐœ

๋ฐฑ๋‘์‚ฐ(Dusan Baek)
../../Resources/kiee/KIEE.2025.74.5.905/au1.png

2025-Present: M.S. degree candidate, Pusan National University

2018-2024: B.S. degree, Kumoh National Institute of Technology

E-mail : dsbaek@pusan.ac.kr

์œคํšจ์›(Hyowon Yoon)
../../Resources/kiee/KIEE.2025.74.5.905/au2.png

2025-Present: Ph.D. degree candidate, Pusan National University

2018-2024: B.S. and M.S. degrees, Kumoh National Institute of Technology

E-mail : hwyoon@pusan.ac.kr

๊น€์ƒ์—ฝ(Sangyeob Kim)
../../Resources/kiee/KIEE.2025.74.5.905/au3.png

2025-Present: Ph.D. degree candidate, Pusan National University

2023-2025: M.S. degree candidate, Kumoh National Institute of Technology

2017-2023: B.S. degree, Kumoh National Institute of Technology

E-mail : syk@pusan.ac.kr

๊ฐ•๊ทœํ˜(Gyuhyeok Kang)
../../Resources/kiee/KIEE.2025.74.5.905/au4.png

2023-Present: M.S. degree candidate, Kumoh National Institute of Technology

2019-2023: B.S. degree, Kumoh National Institute of Technology

E-mail : ghkang@kumoh.ac.kr

๋ฐ•์ˆ˜๋ฏผ(Sumin Park)
../../Resources/kiee/KIEE.2025.74.5.905/au5.png

2025-Present: Combined M.S. & Ph.D. Course candidate, Pusan National University

2020-2024: B.S. degree, Kumoh National Institute of Technology

E-mail : smpark@pusan.ac.kr

์„์˜ค๊ท (Ogyun Seok)
../../Resources/kiee/KIEE.2025.74.5.905/au6.png

2024-present: Assistant Professor, Pusan National University

2020-2024: Assistant Professor, Kumoh National Institute of Technology

2014-2020: Senior Researcher, Korea Electrotechnology Research Institute

2013-2014: Postdoctoral Research Associate, University of Illinois at Urbana-Champaign

2008-2013: M.S. and Ph.D. degrees, Seoul National University

2004-2008: B.S. degree, Kookmin University

E-mail : ogseok@pusan.ac.kr