高壓應用GaN元件探秘

採用氮化鎵(GaN)打造的功率開關電晶體會在性能上超越那些採用矽的功率開關電晶體。美國業者Odyssey Semiconductor開發了一種在GaN元件中現區域選擇性摻雜區的方法,開啟了實現垂直導電元件的機會;本集Podcast邀請到該公司執行長Mark Davidson與主持人一起探討高壓應用的GaN元件結構。

時長: 27:38 | 發佈者: EE Times Taiwan | 發佈時間: 2022-10-27

高壓應用GaN元件探秘

Welcome to PowerUP, a podcast show hosted by Maurizio Di Paolo Emilio that brings light to some of the stories on power electronics technologies and products featured on PowerElectronicsNews.com and through other AspenCore Media publications. In this show, you’ll hear both engineers and executives discuss news, challenges, and opportunities for power electronics in markets such as automotive, industrial, and consumer. Here is your host, editor-in-chief of PowerElectronicsNews.com and EEWeb.com, Maurizio Di Paolo Emilio.

歡迎收聽由Maurizio Di Paolo Emilio主持的podcast節目Powerup。本節目為 PowerElectronicsNews.com 和其他 AspenCore Media 旗下網站的內容帶來活力。在本節目中,您將聽到工程師和高層討論電力電子和汽車、工業與消費性電子等市場的新聞、挑戰和商機。歡迎我們的主持人,Power Electronics NewsEEWeb.com主編Maurizio Di Paolo Emilio

MAURIZIO DI PAOLO EMILIO: Hello everyone, and welcome to this new episode of PowerUP. Today, we’ll be talking about gallium nitride for high voltages. Wide-bandgap power electronic device advancements have lately made impressive strides, mostly because of today’s higher switching frequencies compared with silicon devices and their consequent capacity to rise the power density and efficiency of switch-mode power converters. Power-switching transistors built with GaN are superior to those built with silicon because the material’s properties enable the realization of devices with a much smaller wafer area and an equivalent breakdown voltage or on-resistance and current-handling capacity.

MAURIZIO DI PAOLO EMILIO 大家好,歡迎收聽最新一集的PowerUP。今天,我們將討論高壓應用的氮化鎵。寬能隙電力電子元件的進步最近取得了令人矚目的進步,這主要是因為與矽元件相比,它們如今的開關頻率更高,並且因此具有提升開關模式電源轉換器的功率密度和效率的能力。用 GaN 製造的功率開關電晶體優於用矽製造的電晶體,因為該材料的特性能夠實現具有更小晶圓面積和等效擊穿電壓或導通電阻和電流處理能力的元件。

Despite its success to date for lower-voltage applications, about 650 V and under, the most measured gain-based power device, the high-electron–mobility transistor (HEMT) could be unsuitable for high voltage, medium from 1.2-kV to 20-kV applications, including electric-vehicle drivetrains and many great applications, where silicon carbide is going very well. Odyssey Semiconductor has developed a metal to achieve area selective doped regions in GaN, opening the door to the realization of vertical conduction devices, analogs, to the highly developed device geometries that are standard in silicon and SiC but with all the superior material properties of GaN.

儘管迄今為止在約 650 V 及以下的低壓應用中取得了成功,但高電子遷移率電晶體(HEMT) 可能不適用於1.2 kV至20 kV的高壓應用,包括電動車傳動系統和許多出色的應用,其中碳化矽進展順利。 Odyssey Semiconductor開發了一種金屬來實現GaN中的區域選擇性摻雜區,為實現垂直導電元件、類比元件,還有對矽與碳化矽材料材料來說是標準產品、高度發展的元件種類打開了大門,這些元件將具備GaN所有的優異材料特性。

In this podcast with Mark Davidson, CEO of Odyssey Semiconductor, we will discover more about these features. Let’s talk with Mark.

本集Podcast邀請到Odyssey Semiconductor執行長Mark Davidson,我們將更進一步探討這些特性。讓我們和Mark聊聊。

Hi, Mark. Thanks a lot for joining us. How are you?

Hi Mark,非常感謝你加入我們。你好嗎?

MARK DAVIDSON: I’m great, Maurizio. Great to be connected with you. Thank you for letting me be involved in this podcast today.

MARK DAVIDSON:我很好,Maurizio。很高興能跟你連線,謝謝你邀我上這一集Podcast

MAURIZIO DI PAOLO EMILIO: Thank you. Thanks a lot for this opportunity. So today, we will talk about GaN for high voltages. But before that, tell us more about you. Please introduce yourself, your company.

MAURIZIO DI PAOLO EMILIO:謝謝你,非常感謝有這個機會。所以,今天我們將討論高壓應用的GaN。但在開始前,請告訴我們更多一點你的資訊,請介紹你自己還有你的公司。

MARK DAVIDSON: Yeah, great. Thanks, Maurizio. So yeah, my name’s Mark Davidson, CEO of Odyssey Semiconductor. I started this position in April of this year. I’ll tell you a little bit about the company and then a little bit about myself. So Odyssey was formed with the focus to create vertical GaN power FETs to go after the high-voltage power market. And throughout this podcast, I’ll give you some more detail as to why and how we’re doing that. But that’s our place in the market. And in summary, I would say our job is to bring the switching performance and power efficiency of GaN into voltages currently being addressed by SiC. That’s kind of our position.

MARK DAVIDSON好的,很好;謝謝Maurizio。我的名字是Mark Davidson,是Odyssey Semiconductor的執行長,我是從今年4月開始擔任這個職位。我會告訴你一些關於公司的事情,然後是關於我自己的一些事情。Odyssey的成立宗旨是打造垂直GaN功率FET,以高壓電源市場為目標。在這集Podcast裡我會詳細介紹我們為什麼要這麼做,以及會如何做;這是我們的市場定位。總而言之,我想說我們的工作是把GaN的開關性能和電源效率導入目前以SiC元件來因應的電壓應用領域,這是我們的定位。

For myself, [I’ve spent] 20 years in power semiconductors working for a lot of the large established power and analog companies. I started my career as an engineer in automotive doing powertrain electronics design and working with manufacturing. So I have this background in automotive that I’m finding to be useful, as electric vehicles is one of the markets that we’re going to be pursuing. But yeah, 20 years in power semiconductors, and I worked at a bunch of startups as well. And like I said, since April of this year, I have been CEO of Odyssey Semiconductor based out of Ithaca, New York, on the east coast of the U.S.

至於我自己,我在電源半導體領域有20年的經驗,為許多大型老牌電源和類比公司工作過。我的職業生涯一開始是汽車領域的工程師,從事動力系統電子設計和製造。我發現我在汽車產業的背景很有用,因為電動車也是我們的目標市場之一。所以我在電源半導體領域工作了20年,我也在幾家新創公司待過。而就像我前面說的,我從今年4月開始擔任 Odyssey Semiconductor執行長,我們公司總部是在美國東岸的紐約州伊薩卡市

MAURIZIO DI PAOLO EMILIO: So Mark, let’s start with the advantages of GaN compared with silicon, but also SiC, and which are the problems in high voltage for GaN, more than 650 V. So tell us, please explain the differences between lateral and vertical structure.

MAURIZIO DI PAOLO EMILIO:所以Mark,讓我們從GaN相較於矽的優勢開始,還有SiC,以及 GaN在超過650V的高電壓應用問題。所以先請幫我們解釋水平與垂直元件結構的區別。

MARK DAVIDSON: Yeah, great. Yeah, so if we look at power, you know, the three main alternatives that we see are silicon and IGBTs and I think, you know, you’ve done a lot of coverage. We know that silicon is just run out of juice on high voltage, high efficiency, and high power density. So, you know, kind of the movement away from silicon has been happening for a little while. So then we look against lateral GaN and SiC as the two main alternatives to what we’re doing in vertical. So let me start with lateral GaN. And of course, you know, lateral GaN is GaN-on-silicon or GaN-on-sapphire.

MARK DAVIDSON好的,很好。所以如果我們看一下電源領域,你知道,我們看到的三個主要替代品是矽和 IGBT,我認為,你知道,你們已經做了很多報導。我們知道,矽已經在高電壓、高效率和高功率密度上不敷使用。所以,你知道,尋求矽以外材料的行動已經發生了一段時間。因此,我們將水平式GaN和SiC作為我們在垂直結構上所做的兩個主要替代品。因此,讓我從水平式GaN開始。所謂的水平式GaN是GaN-on-silicon或GaN-on-sapphire

So we’re talking about really a GaN layer on top of a more traditional substrate. And born from really RF, you know, that the structures are HEMTs and were developed for RF, and now being adapted by a few companies to go after power. And you know, with this lateral device, we see a lot of the lateral GaN companies going after laptop chargers and, you know, trying to move into some of the higher-performance markets. But we see lateral GaN really going into what I would call the mid-range. And one of the challenges, of course, with lateral GaN and ability to go to higher voltages is inherent in the structure. And instead of talking about the theory or the technology, let me give you a real example.

所以我們談論的實際上是在傳統基板上的GaN層,實際上是因射頻元件而生;這些結構是 HEMT,是為射頻開發的,現在被一些公司採用以追求功率。而且透過這種水平式元件,我們看到很多水平式GaN供應商都在追逐筆電充電器應用,並且試圖進入一些更高性能市場。但我們看到水平式GaN真正進入了我所說的中階應用。當然,水平式GaN和達到更高電壓的能力所面臨的挑戰之一是該結構固有的。撇開談理論或技術,讓我提供一個真實案例。

We saw a lateral GaN device, power device from a competitor that was rated at 1,200 V, and we were very curious about that. So we were able to do some competitive teardown on that product, and the one thing I’ll tell you is, their die, for the same on-resistance, and in this space, the die size is dictated by the on-resistance, by the RDS(on). For the same on-resistance, their die is 5× bigger than ours. Because when you go lateral, and if you want to increase the voltage capability of the device, you’ve got to go larger die area, where when you go vertical, you know, you increase the thickness a little bit. So to me, that’s a great example of why lateral GaN is really limited in going after these really high-performance, higher-voltage applications. And then, you know, the last alternative, of course, is SiC. And I mean, look, and you’ve covered it well. SiC is going into the broad adoption phase finally after many years in power.

我們看到競爭對手的一款水平式GaN元件,額定電壓為1,200 V,我們對此非常好奇。所以我們能夠對該產品進行一些競爭力拆解分析,而我要告訴你的是,它們的晶片以相同的導通電阻來看,在該空間中,晶片尺寸由導通電阻RDS(on)決定;在相同的導通電阻下,他們的晶片比我們的大5倍。因為當你採取水平結構,如果想提高元件的耐壓能力,就得用更大的晶片面積;而當採用垂直結構時,則會增加一點厚度。對我來說這是一個很好的例子,解釋為什麼水平式GaN在追求這些真正高性能、更高電壓的應用時,確實受到限制。然後,最後一個選擇當然是SiC;這方面你們已有很多的相關報導,在進入電源應用領域多年後,SiC終於被廣泛採用。

And that’s great to see, because I appreciate that the SiC companies are making the investment to move the customers from silicon to, you know, a compound semiconductor option. And SiC, you know, obviously it’s significantly better than silicon, but still limited, and still not as good at what vertical GaN’s going to bring. For example, if we look at, and we’re going to talk a little later in the podcast I think about, we’ll call it the figure of merit. But when we look at the capabilities of SiC, first is vertical GaN. Vertical GaN gives about a 6× to 10× improvement over SiC. In the example I gave, lateral versus vertical GaN, I’ll give the same thing. You know, what that 6× to 10× improvement means is, for the same RDS(on) at, let’s say, 1,200 V, you know, six to 10 of my die will fit inside one SiC die.

很高興看到這一點,因為我很欣賞SiC元件業者正在投資,讓客戶從矽轉向化合物半導體選項。SiC顯然比矽好得多,但仍然有其限制,不如垂直式GaN可以帶來的優勢。例如,我們看一下…稍後我想我們還會在節目中討論到一些,我們將稱之為品質因數。當我們看到SiC的性能,首先是與垂直式GaN相較。與SiC相比,垂直式GaN的改善大約是6到10倍。在我提供的範例,水平與垂直式GaN,我會用相同的東西;你知道,6到10倍的改善意味著,以相同的RDS(on)來看,假設為1,200 V,一顆SiC晶片等同於6到10顆我的晶片。

That’s a significant advantage, not only on induction loss, and of course cost, because cost is proportional to die size, but also on switching frequency, the smaller the device. So GaN is already better than SiC for on switching, and then a smaller die is going to give me an even greater advantage. So we see vertical GaN as that kind of big step. The silicon to SiC step is being taken, and SiC to vertical GaN will be the next step that’s taken, and we’re proud that we’re leading the way in vertical GaN.

這是一個顯著的優勢,不僅在於感應損耗,當然還有成本,因為成本與裸晶尺寸成正比,而且還在於開關頻率,以及更小的元件。GaN在開關方面已經優於SiC,更小的晶片將給我帶來更大的優勢。因此,我們將垂直式GaN視為一大步。從矽轉移到SiC的過程正在發生,而從SiC轉移到垂直式GaN將是下一步。我們很自豪在垂直式GaN領域處於領先地位。

MAURIZIO DI PAOLO EMILIO: So your company, Odyssey Semiconductor, is using high-quality bulk GaN wafers as the substrate for your proprietary vertical conduction power-switching transistors. So this vertical conduction device shape is advantageous because it uses the substrate’s surface area effectively and enables the use of a normally off device and, moreover, isolates high voltages that occur between terminals. So in terms of challenges, tell me which are challenges more about your technology that you are working on. Why do we need vertical GaN? You mentioned early in this case, but what are your customers from the design point of view asking you in this case for specific applications?

MAURIZIO DI PAOLO EMILIO:所以你的公司Odyssey Semiconductor正在使用高品質的塊狀GaN晶圓片,作為你們獨家垂直式導電功率開關電晶體的基板。這種垂直式導電元件的形狀是有利的,因為更有效地利用了基板的表面積,並且能夠使用常關元件,此外,它還隔離了端子之間出現的高壓。因此,就挑戰而言,請告訴我哪些是你們正在研究的技術的更多挑戰。為什麼我們需要垂直式GaN?你先前有提到這個案例,從設計的角度來看,你們的客戶是否針對特定應用提出過什麼要求?

MARK DAVIDSON: Yeah, great. So I’ll start with performance, the performance benefits. And actually, we’ll talk about cost of performance. And I talk to a lot of customers regularly. Although I’m CEO, I really come from a marketing and sales background. You know, and one in particular I’ll talk about in automotive OEM that sees vertical GaN as very, very important for electric vehicles. Moving to 800-V batteries, SiC with 1,200-V capability is there now. I think we’ve seen some teardowns of SiC FETs in the traction inverters, but still too expensive, still too large and bulky. So the problem they want to solve is continuing down that price performance curve for 800-V battery packs in a traction inverter. So that’s, you know, I think a great example.

MARK DAVIDSON好的。我會從性能開始講,性能優勢;實際上,我也會提到性能成本。我經常與很多客戶交談,雖然我是執行長,但我來自行銷和業務背景。我會特別談到的一點是,車廠認為垂直式GaN對電動車非常非常重要,當轉向採用800V電池,具備支援1,200V電壓的SiC已經就緒。我認為我們已經看到牽引逆變器中的SiC FET的一些拆解,但仍然過於昂貴,仍然太大且笨重。因此,他們想要解決的問題是繼續降低牽引逆變器中800V電池組的價格性能曲線。這是我認為一個很好的例子。

And those examples exist in other markets as well, but I think that’s a great example of why the market and customers are looking for vertical GaN. That’s on the cost performance side. If we look on the reliability side, you know, when we go GaN-on-silicon versus GaN-on-GaN, it’s really about defect density. And with our GaN, number one, less defects, and of course, this has a big impact on reliability. But then as we scale, because we scale vertically, we’re not intersecting more defects. So from a reliability point of view, you know, we see vertical GaN-on-GaN as an inherently more reliable solution. Now I’m not saying that the other companies aren’t reliable. They clearly have products that are qualified.

這些案例也存在於其他市場,但我認為這是市場和客戶尋找垂直式GaN的一個很好的例證;那是在性價比方面。而如果我們從可靠性方面來看,當我們選擇GaN-on-silicon與GaN-on-GaN時,它實際上與缺陷密度有關。使用我們的GaN,第一,缺陷更少,當然,這對可靠性有很大影響。但是當我們擴展時,因為我們是垂直擴展,並沒有交叉更多的缺陷。因此,從可靠性的角度來看,我們將垂直式GaN-on-GaN視為本質上更可靠的解決方案。現在我並不是說其他公司不可靠,他們顯然有合格的產品。

They have found ways to overcome the challenges for long-term reliability. But if you just look at material properties, lower defect count and then less intersection because of vertical scale versus the horizontal scale, I think that’s a really big benefit. And I’ll also remind that when we look at the power, discrete business, power FETs, SiC, silicon, they’re vertical conduction devices, right? Power is really designed to be a vertical conduction transistor. And I think we’re bringing that in GaN where it hasn’t been brought before. So I think, you know, we combine all those things. And yeah, of course we still have challenges to solve. We’re not qualified in production yet.

他們找到了克服長期可靠性挑戰的方法。但如果只看材料特性、較低的缺陷數量,然後由於垂直尺度與水平尺度相比,交叉點較少,我認為這是一個非常大的好處。我還要提醒一下,當我們查看電源、離散業務、功率FET、SiC與矽,它們是垂直導電元件,對嗎?電源真的被設計成一個垂直導電電晶體。我認為我們正在將它帶到GaN元件,而這是以前從未導入的。我們結合了所有這些東西;當然我們仍有挑戰需要克服,我們還不到可以量產的資格。

We’ll talk about it at the end of the podcast, I think, but we have our first samples coming out. They’ll be assembled this year and we’ll put them into customers’ hands next year, and we’re going to learn a lot more. We’re going to learn a lot more about what the customers see, what they observe, what they expect from their products. So, you know, we still have some challenges to solve, but I’ll go back to the inherent capabilities of the material, the capabilities of a vertical structure. You know, we know we’re bringing the right combination of technology and solution into the market.

我想我們會在Podcast結束前再談,我們的第一顆樣本已經出來了,它們將在今年組裝,我們將在明年將它們送到客戶手中,我們將學到更多。我們將更充分了解客戶所看到的、觀察到的以及他們對產品的期望。所以,我們還有一些挑戰要解決,但我會回到材料的固有能力,垂直結構的能力。我們知道我們正在將技術和解決方案的正確組合帶到市場。

MAURIZIO DI PAOLO EMILIO: So in terms of manufacturing and cost, so we are talking about vertical GaN. So the manufacturing will be the same obviously on silicon carbide, silicon. So in theory, you are using the same facilities. And in terms of cost, which is the direction? How now and in the future can we compare vertical GaN with the equivalent of silicon and SiC in higher voltages?

MAURIZIO DI PAOLO EMILIO:所以在製造和成本方面,我們談論的是垂直式GaN。因此,無論是在SiC或矽材料上,製造顯然是相同的。所以理論上,使用的是相同的設備。而在成本方面,趨勢走向如何?現在和未來我們如何在更高壓的應用上,比較垂直式GaN與矽和SiC

MARK DAVIDSON: Yeah. And you know, I’m not going to, if it’s okay with you, I’m not going to talk about the cost comparisons between us and silicon, because for silicon, in the places that we’re going, cost doesn’t matter because they’re not meeting the performance requirements. But I think the big question people have is vertical GaN versus SiC.

MARK DAVIDSON好的。但如果你同意的話,我不會談論我們和矽元件之間的成本比較;因為對於矽,在我們鎖定的應用領域,成本不是重點,因為矽元件不符合性能要求。我認為人們面臨的最大問題是垂直式GaN與SiC

MAURIZIO DI PAOLO EMILIO: Yes.

MAURIZIO DI PAOLO EMILIO:好的。

MARK DAVIDSON: So we’ll start with manufacturing. So, you know, at Odyssey, we have our own, I call it a microfab. So we have a 10,000-square-foot fab, and with minimal investment, we can get to 100 wafers per month, probably even more. So we can do quite a bit out of this facility with very modest investment. That’s one of the advantages we have as a company, because, yeah, we’re using all the same equipment as would be used by traditional silicon, but you know, the IP, the know-how, the expertise that we have is how to fabricate vertical GaN devices using this equipment. And that’s the hard part. There are plenty of papers talking about in theory how to build vertical GaN, but what I have is a team of really smart people who have figured out using this equipment, and they’ve figured out how to fabricate vertical GaN power devices and large devices.

MARK DAVIDSON:所以我們從製造開始講。在Odyssey,我們有自己的──我稱之為微型工廠;我們有一個佔地10,000平方英呎的晶圓廠,只需最少的投資,我們每月可以生產100片晶圓,甚至可能更多。所以我們可以用非常少的投資,在這個製造據點做很多事情。這是我們作為一家公司的優勢之一;因為是的,我們使用的設備與傳統矽元件使用的設備相同,但我們擁有的IP、專有技術和專業知識,是如何使用那些設備製造垂直式GaN元件,這是最難的部分。理論上有很多論文在談論如何製造垂直式GaN,但我有一個非常聰明的團隊,他們已經想出如何使用這些設備,他們已經想出如何製造垂直式GaN功率元件和大型元件。

You know, the product that we have in fabric now is our first sample. It’s a 65-mΩ you know, nominal RDS(on) device. So it’s by far not the largest. You know, we will be going to much lower RDS(on) in time. But it’s not just a tiny little test chip. It’s a chip that’s actually going to generate, or it’s going to conduct high power. And we’re doing that using this fully depreciated legacy semiconductor equipment, silicon equipment. What I’m really excited about is, we’re acquiring a new piece of equipment, actually two pieces of equipment. And this equipment was used by a Tier 1, non-analog, non-power, but you know, a Tier 1 semiconductor company in their own fab. We know the equipment was handled very well. We’re buying it for about 10 cents on the dollar. If I was going to buy the new equipment, this equipment new would be millions and millions of dollars.

我們正在打造的產品就是我們的第一個樣品,這是一款65-mΩ的標稱RDS(on)元件;它到目前為止還不是最大的,我們會及時更進一步降低RDS(on)。它不僅僅是一款小小的測試晶片。它個實際上將會是產生或傳導高功率的晶片。我們正在使用完全折舊的傳統半導體設備,生產矽元件的設備來做到這一點。而我真正興奮的是,我們正在採購一套新設備,實際上是兩套設備;該設備曾經被一家Tier One的非類比、非電源半導體公司在他們自己的晶圓廠中使用。我們知道設備能處理得很好,我們只以大概10美分的價格就買到了;如果要購買全新設備,花費會是數百萬美元。

We’re getting it for about 10 cents on the dollar. And that’s a huge advantage for us, obviously, on keeping our costs in control. But we’re able to use it, yeah, of course because of device size and all those things, but really because of the expertise of our team, we have materials and process people who have figured out how to use this equipment to build vertical GaN devices at scale, at eventually high volume, but right now being able to build large devices. So very excited about that. And yeah, like I said, that’s happening in our facility.

我們只花10美分左右的代價就取得該設備,這顯然對我們來說是一個巨大的優勢,可以控制我們的成本。但是我們能夠使用它,當然是因為設備尺寸和所有這些東西,但實際上是因為我們團隊的專業知識,我們有材料和製程人員,他們已經弄清楚如何用這些設備來打造具規模的垂直式GaN元件,最終達到量產;現在能打造大尺寸的元件。我們對此非常興奮,就像我說的,這正在我們的據點發生。

Twenty feet from me right now is the entrance to the fab. So that’s a unique advantage we have, being able to innovate that close to our R&D team, and of course, when we get to production, being able to control fab. As we’ve learned in the last few years, obviously it’s why the CHIPS and Science Act, being able to control source of fab is very important for the semiconductor business. So you know, it’s a huge advantage that we have.

我現在坐的地方就距離晶圓廠入口約20英呎。這是我們擁有的獨特優勢,能夠在我們的研發團隊附近進行創新;當然,當我們開始生產時,能夠控制晶圓廠。正如我們在過去幾年中了解到的那樣,顯然這就是為什麼《晶片與科學法案》認為能夠控制晶圓廠的來源對半導體產業非常重要,這是我們擁有的巨大優勢。

MAURIZIO DI PAOLO EMILIO: So in GaN-on-GaN, so vertical GaN, I see in comparison with other substrate, GaN-on-SiC, so in particular that SiC is much more thermally conducted than GaN. Another thing is that the electromobility in GaN is much higher than SiC, but only in a lateral device. And so if you switch to a vertical device, you could lose some advantages in this case. What do you think?

MAURIZIO DI PAOLO EMILIO:所以在GaN-on-GaN和垂直GaN中,我看到與其他基板,即GaN-on-SiC相較,SiC特別在導熱性上高於GaN。另一件事是GaN的電子遷移率遠高於SiC,但僅在水平元件中。因此,如果切換到垂直式元件可能會失去一些優勢。對此你怎麼看?

MARK DAVIDSON: Yeah. I think on your thermal, you know, that’s a true statement. Of course, we’re able to thin our wafers to improve thermal conductivity, so that, you know, gives us, I’d say, it improves the thermal, to the point where, you know, I think we’ll be okay. And of course, time will tell. We’re getting parts packaged. But I think on the thermal side, we feel pretty good about that. Regarding your point on electromobility, you know, so we look at the whole equation for, we’ll call it figure of merit, figure of merit around specific on-resistance, etc. You know, and there are really three big factors: electromobility, dielectric constant, and then of course critical field.

MARK DAVIDSON你提出的、關於熱的問題確實存在,當然,我們能夠打薄我們的晶圓片以提高導熱性,這讓我們能改善熱的問題,我認為我們可以克服,時間會證明一切。我們正在準備封裝零件,我認為在散熱方面我們相當有信心。關於電子遷移率的問題,讓我們來看整個方程式,也就是品質因數,圍繞特定導通電阻的品質因數,實際上有三個主要元素:電子遷移率、介電常數,當然還有臨界電場。

And in the equation, mobility and dielectric constant, you know, they’re linear in the equation. And you know, yeah, there’s a little bit of what I would call, you know, puts and takes between GaN and SiC. The dominant factor is critical field. So relative to SiC, we have what I’d call a quantifiable advantage over SiC on critical field. But what’s really valuable for us is, in the equation, that factor’s cubed. So it’s to the third power, which is where we get significant advantage, you know, when I talk about that kind of 6× to 10× improvement, it’s really based on that.

在方程式中,電子遷移率和介電常數是線性的,有一點是我稱之為GaN和SiC之間的折衷。主導因素是臨界電場。因此,相對於SiC,我們擁有在臨界電場超越SiC的可量化優勢。但對我們來說真正有價值的是,在方程式中,這個因素是立方的,也就是三次方;這是我們獲得顯著優勢的地方;我前面提到6倍到10倍的改善,實際上是以此為基礎。

So you know, like everything in technology, you know, it’s all about tradeoffs. And I think when we look at that figure of merit, when we look at the overall tradeoffs, you know, we have a pretty distinct advantage at the material level that we’ll take advantage of on our vertical GaN devices.

所以就像技術中的一切,都是與折衷有關。而且我認為,當我們查看該品質因數時,當我們查看整體的折衷,我們在材料層面具備非常明顯的優勢,我們將在我們的垂直式GaN元件上利用該優勢。

MAURIZIO DI PAOLO EMILIO: Which are, if there are differences, issues, in terms of integration, I mean, with respect to on-board drivers that we have on GaN-on-silicon, in this case, differences in terms of lateral and vertical ones.

MAURIZIO DI PAOLO EMILIO:如果存在差異,那就是整合性方面的問題;我的意思是,以GaN-on-silicon的車載驅動器來看,在這個案例中,水平和垂直元件的差異。

MARK DAVIDSON: Yeah. You know, I think, so in our structure, our vertical power FET, we will not be able to do integration. So we will be a discrete FET. It doesn’t mean we won’t have some sensing capabilities, but you won’t see us do what we see some of the lateral GaN companies do. So when you have a HEMT, you could build small, you could put your gate drivers on the same die, and we see that as an advantage they have, and really they need, because, you know, lateral GaN, let’s say GaN-on-silicon as an example, or GaN-on-substrate.

MARK DAVIDSON:在我們的結構中,我們的垂直式功率FET無法進行整合,我們會是一個獨立的FET。這並不意味著我們不會有一些感測能力,你不會看到我們做一些水平式 GaN公司所做的事情;當擁有HEMT 時,可以打造小型產品,可以把閘極驅動器放在同一個晶片上,我們認為這是他們擁有的優勢,而他們真正需要的是水平GaN,例如GaN-on-silicon

You know, they tend to be fabless companies working oftentimes in the same fab as their competitors, and it’s pretty hard to differentiate at the device or process flow level. Right? The design rules are the design rules at the foundry. So the lateral GaN companies, you know, they’re looking to create differentiation through integration, as you say, maybe even with packaging, you know, those sorts of things, right? And there’s a lot of room for innovation there, and we see them doing some very impressive things.

那些公司往往是無晶圓廠業者,經常會與競爭對手用同一家晶圓代工廠,很難在設備或製程層面上差異化,對吧?設計規則是代工廠的設計規則,所以水平式GaN業者,正在尋求透過整合來創造差異化,正如你所說,甚至可能透過封裝,諸如此類的事情,對嗎?那裡有很大的創新空間,我們看到他們做了一些非常令人印象深刻的事情。

And I think that’s why integration’s important on the lateral. But for us, you know, our roadmap is to build a vertical GaN FET, a discrete FET, maybe discrete FETs, right? Maybe integration could be in multi FETs, but we’re going to stay purely in a FET. We don’t see integration on our roadmap.

我認為這就是為什麼整合對水平元件很重要。但對我們來說,我們的技術藍圖是打造垂直式GaN FET、離散式FET,對吧?也許整合可以在多個FET進行,但我們將僅在FET中進行。我們沒有在我們的藍圖看到整合。

 MAURIZIO DI PAOLO EMILIO: So Mark, in conclusion, you announced that you have achieved 1,200 V, and you are fabricating a first-generation engineering sample. So tell me, what areas do you think there will be opportunity with your technology, and what’s next in this case? So are you also providing development boards for testing, for practice, I mean, for your customers?

MAURIZIO DI PAOLO EMILIO:所以Mark,最後的結論,你們宣布已經達到可支援1,200V高壓,並且正在生產第一代工程樣品。那麼你認為你們的技術在哪些領域會有機會,在這種情況下,下一步是什麼?還有你們是否還會為客戶提供用於測試和實作的開發板?

MARK DAVIDSON: Yeah, absolutely. And thanks for taking note. So earlier in September, we made the announcement that we were able to build a 1,200-V vertical GaN FET, and that was really the stated objective of our company. We had already shown the world that we could build a 650- or 700-V vertical GaN FET, which is valuable in the market if we look at a SiC 650-V node, there’s a lot of businesses, a lot of growth there. But of course, in addition to that, we wanted to get to 1,200 V. So we’ve announced we’ve done that, and that was a significant accomplishment for the company.

MARK DAVIDSON好的,當然。感謝你的注意。在9月初,我們宣布我們能夠打造1,200V垂直式GaN FET,這確實是我們公司的既定目標。我們已經向世界展示了我們可以打造650或 700V垂直式GaN FET,如果我們看看 SiC 650V節點,這在市場上很有價值,那裡有很多生意、有很多成長。但當然,除此之外,我們還想達到1,200 V。我們宣布我們已經做到了,這對公司來說是一項重大成就。

So yeah, so we’re fabricating samples. We’ll put them in packages by the end of the year, do our internal testing, and then pass them to the initial customers. I’m committing to three customers at the beginning, and the markets we’re going to start with are, there are some automotive companies. So we’ll pick one that we’ll give first samples to. I can’t go too wide, because we’re a small team and I don’t want to overwhelm the team with too many customer inputs. So automotive is one, electric vehicles, of course. We have a great relationship with an innovative electric motor company that’s looking, you know, they’ve moved from silicon to SiC and now they’re looking for us to take them to that next technology step with high-voltage GaN. So that’s another company that we’ll be giving initial samples to.

我們正在製造樣品,將在年底前封裝並進行內部測試,然後將它們提供給初始客戶。我們一開始能承諾三家客戶,而一開始會進入的市場中,有一些是車廠,所以我們會選擇一家提供第一個樣品。我們不能一下子跨太大步,因為我們是一個小團隊,我不想有太多的客戶讓團隊無法應付,所以車用會是其中之一,當然是電動車。我們與一家創新的電動馬達業者建立了良好的關係,該公司已經從矽元件轉向SiC,正在尋找利用高壓GaN的下一個技術步驟;這是我們會提供第一批樣品的另一家公司。

We see electric motors. I read a stat: About half the energy in the U.S. is consumed by electric motors. And honestly, I would fact-check that, but it’s a significant amount. And I was surprised by that, and I understand why the electric motors are so excited to come up with a higher power density, more efficient solution provided by our technology. Third market is renewable, DC-to-AC inverters for solar, photovoltaics, etc. We see that as an opportunity as well. And then, you know, we have some conversations going with some companies that built industrial power supplies. I have a call next week with a company that does power for high-rail and government applications, space, etc.

關於電動馬達,我看到一個統計數字:美國大約有一半的能源是被電動馬達消耗的。老實說,我會去做事實查驗,因為這是一個很大的數字。我對此感到很驚訝,我可以理解為什麼電動馬達業者會對我們的技術可提供的更高功率密度、更高效率如此興奮。第三個市場是太陽能光電等再生能源使用的DC-AC逆變器,我們也將之視為商機。我們已經與一些製造工業用電源供應器的業者進行洽談。接下來我還會與一家為高鐵和政府應用,還有航太應用提供電力的業者洽談。

So, you know, we see a lot of electrification, sustainability, driving voltages higher, and obviously, we see that’s the problem we’re going to go solve. And then to your last question, for sure, I have a team we’re just building now of systems and applications, building evaluation boards, demo platforms, etc. So yeah, of course we’ll give discrete FETs to people to test, but we also want to give them some boards where they can just plug them in and see the performance benefits of our products. So evaluation boards, demo boards will absolutely be part of the go-to-market strategy.

我們看到很多電氣化、永續、驅動更高電壓的需求,顯然這就是我們要解決的問題。然後是你的最後一個問題;當然,我們有一個團隊正在打造系統和應用、打造評估板與展示平台等等工具。所以是的,我們當然會提供離散FET給客戶測試,我們也想提供一些開發版,讓他們可以實際插上電源看看我們產品的性能優勢,評估板、展示板絕對是產品上市場戰略的一部分。

MAURIZIO DI PAOLO EMILIO: Great. So looking forward to seeing vertical again in the near future. Thank you, Mark. Thanks a lot for joining us. It’s been a pleasure to have you in this podcast. Thank you.

MAURIZIO DI PAOLO EMILIO太好了,期待在不久的將來能看到垂直式GaN元件問世。謝謝Mark,非常感謝你加入我們。很高興在這一集的Podcast能邀請到你,謝謝。

MARK DAVIDSON: Maurizio, thank you for the great questions. It was a pleasure speaking with you. Thank you.

MARK DAVIDSON:謝謝Maurizio提出的這些好問題,很高興與你談話。謝謝。

MAURIZIO DI PAOLO EMILIO: After talking to Mark, SiC is significantly better than silicon, but still limited, and still not as good as what vertical GaN is going to be. When we look at the capabilities of SiC versus vertical GaN, vertical GaN, according to Mark, gives about a 6× to 10× improvement over SiC. Mark said if you just look at the material properties, we see lower defect count and then less intersection because of vertical scale versus the horizontal scale. There are still challenges to solve, but as Mark said, we have our first samples about vertical GaN.

MAURIZIO DI PAOLO EMILIO在跟Mark聊過之後,我們了解SiC明顯優於矽元件,但仍有其限制,並且達不到垂直式GaN的水準。當我們比較SiC與垂直式GaN的能力時,根據Mark的說法,垂直式GaN的性能比SiC高大約6到10倍。Mark說,如果你只看材料特性,我們會發現缺陷數量較少,然後由於垂直尺度與水平尺度相比,交叉點較少。雖仍有挑戰待克服,但正如 Mark 所說,將有第一款垂直式GaN的樣品。

They are using all the same equipment that will be used by traditional silicon, but the IP expertise how to fabricate vertical GaN devices using this equipment is a challenge. But according to Mark, they have to figure out how to fabricate vertical GaN power devices. They will not be able to do integration. They will be a discrete component. They were able to build a 1,200-V vertical GaN, according to Mark. There is a lot of business, a lot of growth there.

它們採用傳統矽元件使用的所有相同設備,而如何使用那些設備打造垂直式GaN元件的IP/ 專業知識則是一個挑戰。根據Mark的說法,他們必須弄清楚如何製造垂直式GaN功率元件。不過該類元件無法進行整合,將是離散元件的形式。而據Mark介紹,他們能打造1,200V垂直式GaN,那裡有很多業務、很多成長機會。

 

參考原文GaN Devices Design for High Voltages

 

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