Thank you, Rick. Please turn to Slide 10 for December quarter 2019 financial highlights. This was a strong quarter for KLA with revenue and EPS each coming in at the high end of our guidance ranges. Total revenue for the December quarter was $1.509 billion which was at the upper end of the range of guidance of $1.435 billion to $1.515 billion. Gross margin for the quarter was 60.8% in the upper end of the guided range for the quarter of 60% to 61% driven by incremental revenue growth and product mix. Operating margins was at 34%. GAAP EPS was $2.40 and non-GAAP EPS was $2.66. Both of which were also at the upper end --of the range of guidance at $2.13 to $2.43 and $2.39 to $2.69 respectively. Cash from operations and free cash flow were both strong and above our internal targets coming in at $388 million and $353 million respectively. Our financial results this quarter were exceptionally strong all around and we remain laser focused on our overall execution, as well as our integration and synergy plans for Orbotech. During the quarter, we remained consistent and effective in our capital return framework by returning 119% of quarterly free cash flow to investors. Our capital return was accomplished by repurchasing $285 million of common stock and also distributing $135 million in quarterly dividends. We currently have $1.3 billion remaining under our share repurchase authorization and plan to continue to execute our repurchasing consistently going forward. A key pillar of our investment thesis is KLA long-standing commitment to returning cash to shareholders. For calendar 2019, KLA returned approximately $1.5 billion or 127% of our free cash flow to shareholders through our dividend and share repurchase programs. Our capital return included more than $1 billion in stock buybacks. Please turn to Slide 11 for revenue breakdown by reportable segments and end markets. Revenue for the semi process control segment which includes the associated service business was healthy at $1.248 billion in the quarter, up 7% sequentially on the back of continued strength and foundry and logic. As Rick mentioned, our initial view of the WFP demand environment for 2020 is for solid growth off of a better than expected finish to 2019, driven by continued strong investment from multiple foundry and logic customers. Investment in the EUV and expanded memory investment in the year. In addition, continued high levels of demand from native China is expected to contribute to overall industry growth in 2020. As I mentioned, foundry was very strong in Q4 at approximately 52% of semi process controlled revenue, up from 44% last quarter. Memory was 40% in December, down from 43% last quarter. Logic was 8% versus 13% last quarter and in line with our expectations. I'll turn now to the specialty semiconductor process segment. As a reminder SPTS was formerly part of Orbotech and as a leader in TBD and H process solutions in fast-growing specialty semiconductor applications like MEMS, sensors, power and RF devices as well as in advanced packaging markets. Revenue for SPTS was $75 million, up 9% sequentially. While SPTS revenue for 2019 was impacted by global trade issues, we expect 2020 to be a strong year -- to be a year of strong growth driven by expanding RF demand to support 5G investment and a potential recovery in the automotive electronics market in the second half of the calendar year. On a very encouraging note, SPTS has ended the December 2019 quarter with record backlog and quarterly bookings. Revenue for the PCB display and component inspection segment was $186 million, up 4% sequentially and in line with expectations. This segment includes the former PCB and display businesses of Orbotech and KLA's component inspection business. After a cyclical low, we expect 2020 to be a modest year growth for PCB driven by the transition to 5G smartphones. Please turn to Slide 12 for a breakdown of revenue by major products and region. The distribution of revenue by major product category in the December quarter was as follows. Wafer inspection was 40%; patterning which includes reticles inspection was 19%; wafer inspection and patterning are part of our semiconductor process control segment. Specialty semiconductor process was 4%; PCB displaying component inspection revenue was 9%; service was 24% of revenue in the quarter; other was 4%. In terms of regional split, Taiwan was 30%; China was 25%; Japan was 13%; Korea was 12%; the US was 11%; Europe was 6% and the rest of Asia was 3%. Please turn to Slide 13 for other income statement highlights. Total operating expenses were $391 million in the quarter including $220 million of R&D expense. Operating expenses were slightly higher than expected in the quarter due to non headcount related engineering and development expenses and modest variable compensation adjustments. Operating margin was 60 basis points higher than modeled at 34.8%. Other income and expense in the December quarter was $38 million. The effective tax rate was 13.5% in line with our long-term tax planning rate of 14%. Going forward, based on our expectations for the geographic distribution of profit, you should now use 13% as the long-term tax planning rate. Net income is $422 million and we had just under $159 million diluted weighted-average shares outstanding. Please turn to Slide 14 for a look at our balance sheet highlights and debt maturities profile. We ended the quarter with $1.7 billion in cash. Total debt of $3.4 billion and a flexible and attractive debt maturity profile supported by investment grade ratings from all three agencies. In October, we retired our $250 million, 3.375% senior notes due November 2019. We intend to refinance our $500 million senior notes due November 2021 during the March quarter. Please turn to Slide 15 for review of free cash flow. KLA has a history of consistent free cash flow generation and high free cash flow conversion. Over the past five years, we have averaged 99% free cash flow conversion and in calendar 2019 it was nearly 90%. Our innovation and differentiation in the marketplace are what drives our industry-leading growth and operating margins and ultimately our free cash flow conversion. Please turn to Slide 16 for a review of our capital return to investors. KLA continues to execute on its commitment to return capital shareholders in the form of both dividends and share repurchases. The dividend payout has increased at a CAGR at 15% since inception 13 years ago. Share repurchases have also increased over the years with the average price paid for repurchase shares being slightly under $70 and with approximately $3.8 billion deployed for repurchases since 2010. The only exception to the company systemic repurchasing activity was during the periods when it was blacked out due to acquisition proceedings. Please turn to Slide 17 for March quarter 2020 guidance. The fluid situation accompanying the Coronavirus response is adding complexity to our forecasting process. As seen with others, we are operating with key assumptions regarding the resumption of business activities in China both in Hubei province in addition to the rest of the country. To date, we do not expect a protracted disruption of our business for calendar year 2020. Policy changes regarding the response could affect our ability to ship and support shipments into China as well as the access key components from our China based supply chain necessary to meet system shipment commitments to our worldwide customer base. In short, this is a situation with limited visibility that could impact our near-term results and we will be prudent in providing you with the best information we have as we proceed through the quarter. As Rick mentioned, the range of guidance has been widened to reflect this quarter's uncertainty and our current estimate of potential disruption. We expect total revenue to be in the range of $1.325 billion to $1.525 billion in the March quarter. This revenue guidance would have approximately been 3% to 5% higher to midpoint without the adjustments for the Coronavirus impact. Foundry is forecasted to be about 60% and semi process control system revenue in the March quarter depicting the strength we continue to see amongst our foundry customer base. We expect memory to be approximately 28% of system revenue, reflecting continued headwinds we see in the memory market. Logic is expected to be about 12% of semi process control system revenue in next quarter. Based on product mixed expectations for the March quarter, we forecast gross margins to be in the range of 59.5% to 61.5%. Operating expenses will be in the range of $380 million to $385 million, down sequentially from December as prototype material expenses normalized to run rate. Given expected revenue levels for 2020, new product development investments of multiple product technologies to support the industry's transition to high-volume production of EUV lithography. And initiatives to reduce our long-term structural cost position, we expect quarterly operating expenses to remain in this range for the remainder of the calendar year. For 2020 operating margin, we are running the company and to perform in line with the $5.5 billion to $6 billion revenue interval of our business model presented at Investor Day back in September. We expect other interest and expense to be approximately $39 million in the quarter and the effective tax rate to be 13%. For earnings, we expect GAAP diluted EPS of $1.79 to $2.57 per share and non GAAP diluted EPS at $2.04 to $2.82 per share. Our EPS guidance is based on a fully diluted share count of approximately 158 million shares. In conclusion, the December quarter results demonstrated strong performance and relative strength for KLA across many areas of our business. With our diversified end markets, continued technology leadership across a broadening product portfolio, and operational discipline, KLA is delivering on our mission, strategy and objectives. As we begin the new year, calendar 2020 is shaping up for another year of growth in line with or slightly better than our long-term revenue growth rate target of 7% to 9% earnings per share growth of 1.5x the revenue growth rate and demonstrating progress towards our 2020 revenue and non-GAAP EPS targets of $7 billion to $7.5 billion and $14.50 to $15.50 per share. With that I'll now turn the call back over to Kevin to begin with the Q&A.